U.S. patent application number 12/963798 was filed with the patent office on 2012-06-14 for subsurface vortex assisted distributed propulsion active hull.
Invention is credited to Ron M. King.
Application Number | 20120145066 12/963798 |
Document ID | / |
Family ID | 46198027 |
Filed Date | 2012-06-14 |
United States Patent
Application |
20120145066 |
Kind Code |
A1 |
King; Ron M. |
June 14, 2012 |
Subsurface Vortex Assisted Distributed Propulsion Active Hull
Abstract
High velocity subsurface craft, apparatus or method positively
affecting propulsion and limiting drag by the use of a rotating
body with selected Surface Treatment. The Active Hull Platform
provides Apparent Flows that allow for shorter more dispersed blade
arrays and boundary layer management that impacts vorticity on skin
surfaces by controlling the angular momentum of the vortices
formed. By converting drag forces into thrust, vortices need not be
avoided and an even non pulsating distributed thrust is the
result.
Inventors: |
King; Ron M.; (Port Angeles,
WA) |
Family ID: |
46198027 |
Appl. No.: |
12/963798 |
Filed: |
December 9, 2010 |
Current U.S.
Class: |
114/333 ;
114/337 |
Current CPC
Class: |
F42B 19/125 20130101;
F42B 10/38 20130101; B63G 8/26 20130101; B63B 1/107 20130101; B63H
5/00 20130101; B63H 1/12 20130101; B63G 8/08 20130101; B63H
2001/122 20130101; B63B 2001/345 20130101; Y02T 70/121 20130101;
B63H 2023/005 20130101; Y02T 70/10 20130101 |
Class at
Publication: |
114/333 ;
114/337 |
International
Class: |
B63G 8/08 20060101
B63G008/08; B63G 8/22 20060101 B63G008/22 |
Claims
1. A submersible Craft, apparatus or method that utilizes boundary
layer conditions and distributed propulsion comprising: (1) the
Active Hull Platform.
2. A submersible Craft, apparatus or method of claim 1 further
comprising: (1) an Active Hull; and (2) managed Apparent Flow by
rotational and fore-aft velocity sensors and velocity control
systems; and (3) means of sealing, expanding, controlling or
limiting the flow of fluids in Area (2) to control fluid properties
and fluid dynamics including mass flows, boundary layer, and shear
layer conditions in Area (2); and (4) Surface Treatment in Area (1)
or Area (1) and Area (2).
3. An underwater Craft or apparatus that utilizes boundary layer
conditions and distributed propulsion comprising: (1) an Active
Hull; and (2) managed Apparent Flow in Area (1) and Area (2); and
(3) Surface Treatment in Area (1) or Area (1) and Area (2).
4. A submersible Craft or apparatus that utilizes boundary layer
conditions and distributed propulsion comprising: (1) an Active
Hull; and (2) means of power and power conveyance to all systems
including rotation of the Active Hull and traditional propulsion
when applicable such as propellers or screws for the Fixed Hull
within; and (3) means to provide anti-torque for the inner Fixed
Hull to stabilize rotational moments; and (4) mechanical and/or
electromagnetic means for support and bearing including radial and
thrust bearing to limit noise and friction between the Active Hull
and Fixed Hull; and (5) velocity sensors and control systems to
measure and control rotational velocities for the Active Hull and
fore-aft velocities for the Fixed Hull and Craft and maintain some
ratio of the two; and (6) means of balancing the Active Hull either
during fabrication or during operation or both to allow smooth
running and less bearing pressures; and (7) means of controlling
ballast to regulate buoyancy including maintaining neutral buoyancy
either during fabrication or during operation or both for the
Active Hull and Fixed Hull within; and (8) means of sealing,
expanding, controlling or limiting the flow of fluids in Area (2);
and (9) at least one of the following: a. traditional means of
accelerating and directing mass flows into and out of Area (2) such
as turbine fins, fixed and/or variable blades, and nozzles; b.
traditional means of propelling, guidance, ballasting, and/or
stabilizing the Fixed Hull within allowing the Active Hull to
become inoperable, disengaged from power, or jettisoned and still
maintain a functioning Craft; c. traditional means of propelling,
guidance and/or stabilizing the Active Hull that are used in
conjunction with Surface Treatment in Area (1); d. Surface
Treatment in Area (1); e. a means of controlling fluid properties
and additives in Area (2); f. Surface Treatments in Area (2).
5. A submersible Craft or apparatus of claim 4 wherein: (1) the
Active Hull partially covers an internal Fixed Hull that is a
Pressure Hull; and (2) means of power such as nuclear power to
generate electrical energy and rotate the Active Hull and
traditional means of thrust such as propellers in the Fixed Hull
when applicable; and (3) power conveyance or torque on the Active
Hull is done traditionally by mechanical means or accomplished by
electromagnetic means making the Active Hull a large rotor and the
Fixed Hull a stator or utilizing both mechanical and
electromechanical means to rotate the Active Hull; and (4) computer
aided balancing by controlling chambers in the Active Hull that can
be filled or purged with surrounding fluid during operation to
correct for imbalance; and (5) computer aided ballast system in the
Active Hull coordinating the chambers of the ballast system with
the balancing system to maintain a neutral buoyancy within the
Active Hull or such buoyancy as needed; and (6) fluid is allowed to
enter and equalize pressure with minimal through flow in Area (2)
making the Active Hull a Light Hull and affecting fluid dynamics in
the Area (2); and (7) traditional means of propelling, guidance,
ballasting, and stabilizing the Fixed Hull within allowing the
Active Hull to become inoperable or jettisoned and still maintain a
functioning Craft; and (8) Surface Treatments Fixed or Variable on
the external Skin surfaces of the Active Hull in Area (1) including
at least one of the following: (a) Vortex Generators that allow for
the creation of non random specific vortices within the boundary
layer that delivers at least some energy in the forward direction
to result in a distributed thrust; (b) vortex enhancers which
absorb or extract energy delivered from vortices to the skin within
the boundary layer such as cilia or hair like projections,
structures such as shelves or geometric shapes or the like that
vortices can react with and transfer momentum; (c) vortex
protection to maintain the momentum of vortices moving in an
advantageous direction and position such as corrugations, cells or
the like within the boundary layer; (d) Fixed and/or Variable
Blades or other elements that interact with bulk flow; and (9) Area
(2) Surface Treatments Fixed or Variable and fluid additives
including at least one of the following: (a) Vortex Generators that
allow for the creation of vortices within the boundary layer that
delivers at least some energy in the forward direction to result in
a distributed thrust; (b) vortex enhancers which absorb or extract
energy such as cilia hair like projections, rough surface or
structures within or on the skin within the boundary layer such as
shelves or geometric shapes or the like that vortices can react
with or against and exert or transfer momentum; (c) vortex
protection to keep the momentum moving in an advantageous direction
such as corrugations, cells or the like; (d) surface roughness,
cilia or methods to increase friction between the fluid in Area (2)
and the inside surfaces of the Active Hull to facilitate and
accelerate the rotation of fluid in Area (2); (e) Fixed and/or
Variable Blades or other protuberances that can take advantage of
the rotational flows in Area (2); (f) fluids, fluid additives and
methods of controlling properties in Area (2) such as low shear
fluids and/or rheological fluids to positively affect such things
as drag, sound attenuation, magnetic flux, and viscosity.
6. A submersible Craft or apparatus of claim 4 wherein: (1) fluid
is allowed to enter and exit in an appreciable manner in Area (2);
and (2) Surface Treatment Fixed and/or Variable in Area (2) on the
external surface of the Fixed Hull being turbine fins or short
blades with pitch to increase mass flow and add thrust to the
Craft; and (3) nozzles to direct and improve thrust from the
increased mass flows for guidance or propulsion or both; and (4)
Surface Treatment in Area (2) on the internal surface of the Active
Hull allowing increased friction on the surface such as a roughed
surface; and (5) Surface Treatments Fixed or Variable on the
external Skin surfaces of the Active Hull in Area (1) including at
least one of the following: (a) Vortex Generators that allow for
the creation of non random specific vortices within the boundary
layer that delivers at least some energy in the forward direction
to result in a distributed thrust; (b) vortex enhancers which
absorb or extract energy delivered from vortices to the skin within
the boundary layer such as cilia or hair like projections,
structures such as shelves or geometric shapes or the like that
vortices can react with and transfer momentum; (c) vortex
protection to maintain the momentum of vortices moving in an
advantageous direction and position such as corrugations, cells or
the like within the boundary layer; (d) Fixed and/or Variable
Blades or other elements that interact with bulk flow.
7. A submersible Craft or apparatus of claim 4 wherein: (1) fluid
is not allowed to enter Area (2) utilizing seals such as face
seals, bearing seals and shaft seals making Area (2) dry and the
Active Hull a Pressure Hull; and (2) sound attenuation added to
Area (2); and (3) Surface Treatments Fixed or Variable on the
external Skin surfaces of the Active Hull in Area (1) including at
least one of the following: (a) Vortex Generators that allow for
the creation of non random specific vortices within the boundary
layer that delivers at least some energy in the forward direction
to result in a distributed thrust; (b) vortex enhancers which
absorb or extract energy delivered from vortices to the skin within
the boundary layer such as cilia or hair like projections,
structures such as shelves or geometric shapes or the like that
vortices can react with and transfer momentum; (c) vortex
protection to maintain the momentum of vortices moving in an
advantageous direction and position such as corrugations, cells or
the like within the boundary layer; (d) Fixed and/or Variable
Blades or other elements that interact with bulk flow.
8. A submersible Craft or apparatus of claim 1 or claim 3 or claim
5 wherein: (1) stabilizing, propulsion, ballast and anti-torque on
the inner Fixed Hull is by traditional means allowing the Active
Hull to become inoperable or jettisoned and still maintain a
functioning Craft; and (2) additional anti-torque supported by a
side thruster in the sail; and (3) the Surface Treatments in Area
(1) are low drag Vortex Generators and cilia; and (4) Surface
Treatments in Area (2) are Fixed and/or Variable Blades on the
Fixed Hull and a roughed surface on the inside surface of the
Active Hull; and (5) Area (2) additives to increase magnetic
flux.
9. A submersible Craft or apparatus of claim 1 or claim 3 or claim
5 wherein: (1) two or more pair of counter rotating Active Hulls
are used; and (2) traditional propulsion is introduced from the
Fixed Hull; and (3) side thruster in the sail with and stabilizers
in the Fixed Hull to provide anti-torque; and (3) Surface
Treatments in Area (1) are low drag Vortex Generators and Fixed
and/or Variable Blades along with a cilia; and (4) the Surface
Treatments in Area (2) are Fixed and/or Variable Blades on the
Fixed Hull and a roughed surface on the inside surface of the
Active Hull; and (5) Area (2) additives to decrease friction and
increase magnetic flux.
10. A submersible apparatus of claim 1 or claim 3 or claim 5
wherein: (1) One or more apparatus are placed below the surface for
the purpose of propelling a ship on or above the surface.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] None
GOVERNMENT INTEREST
[0002] None
JOINT RESEARCH
[0003] None
SEQUENCE LISTING
[0004] None
BACKGROUND OF THE INVENTION
A. Field of the Invention
[0005] The field of this invention relates generally to drag,
stealth, vortices, and propulsion in subsurface craft. More
specifically it relates to managing specific Apparent Flows over
selected Surface Treatment to exploit those forces available and
generate distributed propulsion in underwater craft and
devices.
B. Description of Related Art
[0006] U.S. Pat. No. 4,516,747 Lurz, 1985, Method of and apparatus
for controlling the boundary layer flow over the surface of a body
[0007] U.S. Pat. No. 5,791,275 Bandyopadhyay, 1998, Surface layer
comprising micro-fabricated tiles for electromagnetic control of
fluid turbulence in sea water. [0008] U.S. Pat. No. 4,812,251
Stangroom, 1989, Electro-rheological fluids/electric field
responsive fluids [0009] U.S. Patent 20070175380 Au, 2007, Water
craft with new configuration of active hulls and stationary hulls
for better hydrodynamic performance . . . . [0010] U.S. Pat. No.
4,671,474 Haslund, 1984, Fluid control apparatus and method
utilizing cellular array containing mini-vortex flow patterns
[0011] U.S. Pat. No. 3,578,264 Kuethe, 1971 Boundary layer control
of flow separation and heat exchange [0012] U.S. Patent 005417391
Savitsky, 1995, Method for control of the boundary layer on the
aerodynamic surface of an aircraft, and the aircraft provided with
the boundary layer control system [0013] U.S. Pat. No. 5,171,623
Yee, 1990, Drag reducing surface depressions [0014] U.S. Pat. No.
5,058,837 Wheeler, 1992 Low drag vortex generators showing both
left and right handed vortices [0015] U.S. Patent 20080121301
Norris, 2008, Externally mounted flow duct generators for flow duct
passage [0016] U.S. Pat. No. 6,427,948 Campbell, 2002 Controllable
vortex generator [0017] U.S. Pat. No. 6,963,810 Mangalam 2005
Method and system for locating flow feature indicators in three
dimensional flow regimes [0018] U.S. Pat. No. 5,265,069 Wardle 1993
Blanket array adhesion system [0019] U.S. Pat. No. 4,734,067
Elias-Reyes, 1988, Hydro-rotor [0020] U.S. Patent 20090200416 Lee,
2009, Boundary layer propulsion airship [0021] U.S. Patent
20020152947 Hilleman, 2002, Bow mounted system and method for jet
propelling a submarine [0022] U.S. Pat. No. 6,659,030 Ha, 2003,
Apparatus and method for decreasing drag force by controlling
turbulent flow on hull surface of ship [0023] U.S. Pat. No.
6,508,188 Dong, 2003 Drag-free hull for marine vessels [0024] U.S.
Pat. No. 3,779,199 Mayer 1973 Boundary layer control means [0025]
U.S. Pat. No. 6,948,910 Polacsek 2005, Spirial Based Axial Flow
Devices [0026] U.S. Patent 20090250129 Bernitsas 2009 Enhancement
of vortex induced forces through surface roughness control [0027]
U.S. Pat. No. 3,730,123 Lang, 1973 High speed ship with submerged
hull [0028] Lathrop, Fineberg, & Swinney Volume 46, Number 10
Physical Review Letters Mar. 9, 1992 Turbulent Flow between
Concentric Rotating Cylinders at Large Reynolds Number
http://www.pppl.gov/.about.mnornber/Documents/Papers/Lathrop/Transition%2-
0to%20 shear-driven%20turbulence%20in%20Couette-Taylor%20flow.pdf
or http://complex.umd.edu/papers/PRLCouette1992.pdf [0029]
Investigation of Vortex generators for Augmentation of wind turbine
power performance. Dayton A Griffin December 1996 NREL/SR-440-21399
http://www.osti.gov/bridge/purl.cover.jsp;jsessionid=EB6528188B0B258C0707-
4EEA0C 42EF7B?purl=/414367-2i25d4/webviewable/
[0030] The fore-aft motion of Fixed Hulls is generally affect most
by skin drag which produces vortices in the boundary layer. The
energy stored in the angular momentum of the fluid or vortices
coalesces in the boundary layer and shear layer and forms large
vortices or break away vortices known as von Karman vortices. As
these eddies are shed or separate from the craft they do so at
great expense or drag to the efficient fore-aft motion of the
craft.
[0031] With Fixed Hulls, all net drag forces traditionally are
overcome by the propeller or centralized propulsion system which as
the craft increases in size and speed increases the problem of
hydrodynamic noise and cavitation around the propulsion system. The
application of power to the rear of a craft creates an inverted
pendulum, with stability and guidance problems. The application of
power or guidance to the forward position of a craft cause
turbulent flows that increase drag and noise aft down the length of
the craft. The stern drive requires the vehicle to be pushed
through the water, which generates geometrically disproportionate
wave drag resistance with any increase in speed. This frontal wave
generation limits stability, efficiency and speed. Most importantly
the more concentrated approach to thrust gives an uneven pulsating
noisy result.
[0032] A moving submerged vessel or underwater craft that is
subject to hydrodynamic noise is easily detected, located and
identified as these noises have a unique quality for each craft.
Stealth is generally a high priority in underwater craft such as
submarines with velocity being the factor that has been reduced to
maintain stealth. U.S. Pat. No. 6,659,030 and U.S. Pat. No.
3,779,199 are two examples that sucked and ejected large volumes of
fluids to vary the turbulent field and improve propulsion. They
require large pumps or propellers that would cause large Reynolds
numbers and noisy cavitation in an underwater craft.
[0033] With traditional fore-aft motion on Fixed Hulls, random
vortices using scales or texturing can be developed with slight
benefit thus giving surface texturing or scales a small statistical
advantage over a smooth skinned Fixed Hull as seen in U.S. Pat. No.
5,171,623. Vortex Generators (VG) on Fixed Hulls or wings have only
been beneficial at certain times and not at others and thus within
the art there are controllable or Variable VG that are utilized
during take off and landings and not during cruise conditions. A
Variable VG is illustrated in U.S. Pat. No. 6,427,948.
[0034] U.S. Pat. No. 4,516,747 is a method for controlling the flow
in the boundary layer at the surface of a body over which flow
takes place, based on the active change of the original motion of
flow particles in close proximity to the surface. It doesn't
utilized VG or an Active Hull but rather numerous sensors and
vibration transmitters to alter a low volume flow. Similarly U.S.
Pat. No. 5,791,275 utilizes electromagnetic tiles to alter flow at
the micro level near the skin surfaces which would require a very
large complex fragile system on the exterior of the craft.
[0035] Dynamic hulls or hulls with parts moving across their
surface have also been explored previously. U.S. Pat. No. 6,508,188
considers a conveyer approach to "push" on fluid on a more standard
above surface boat hull with obvious limitations to speed and
stealth. U.S. Pat. No. 4,734,067 is closer in appearance externally
to the concept described herein but it uses an auger approach or "a
helical flight" to push on fluid to give an equal and opposite
reaction in the forward direction. An auger or a flight is excluded
from the definition of Surface Treatment used herein for two
reasons. They do not satisfy the "distributed" portion of the
definition because when motionless they cover little surface area
as seen from above and they do not address drag. Elias-Reyes does
however develop one of many possible systems to mechanically rotate
a device from inside a craft that could be utilized by this
invention.
[0036] U.S. Pat. No. 6,948,910 develops a class of rotor blades
that mesh with flows outside the boundary layer in the axial shear
plane and take advantage of some of the energies normally lost
through separation of vortices on propellers or blades. Polacsek's
blades make no attempt to limit the drag vortices on the skin of
the hubs that employ his blades. Clearly his blades have a
different purpose and would be far more fragile than the more
traditional shorter Blades described herein. His devices are
mentioned as they are axial flow devices and take on some of the
same problems dealt with herein but further down stream and within
the art of blade design. He does develop the useful concept of a
"meta element" with a minute positive thrust gleaned from drag
forces along his blades. Most importantly he clearly describes the
difficulties and "imponderabilities" involved with a mathematical
approach or modeling to complex flow problems.
[0037] Prior art also establishes a large rotating fan body with
shrouds that is bow mounted that increases flows down the external
surface areas of a submarine that has random surface treatment such
as scales or dimples on the skin. (See U.S. Patent 20020152947) The
purpose is to reduce the bow wave and he does address large
portions of the external skin of the craft by energizing the
boundary layer. Hilleman also gives an excellent history of prior
art and the problems inherent therein. However his invention does
not address the direction of bulk flow over the hull and therefore
has no opportunity to create some advantage from specific VG. He
would also have a very noisy system particularly if he employed the
supercavity characteristics he describes.
[0038] Prior art in naval craft does utilizes boundary layer forces
from vortices generated on the skin of the craft. U.S. Patent
20090250129 gives a clear account of Vortex Induced Forces and
Motion (VIFM) on a bluff body. He utilizes surface roughness to
produce random vortices and then captures or harness those vortices
as a source of power. He is not concerned with controlled vortex
generation on those surfaces but his studies do show the harnessing
of useful power within vortices.
[0039] Propellers and Fixed Hulls have pressed limits so far in
subsurface vessels in order to accommodate a larger faster quieter
envelope that now nothing is too complicated or fragile to be
overlooked. Biometrics has been explored to help with the solution
through robotic fish which use a "flexible" body or hull utilizing
vortices to affect greater relative mass flows than their tails
alone could provide. However, the state of the art for craft
utilizing vortices and flexible dynamic hulls is far from
delivering large payloads under harmful conditions.
[0040] The other area of active or dynamic hulls that has been
studied has a rotation on an axis perpendicular to the longitudinal
or fore-aft axis and is generally meant to be a floating craft. One
of the more common examples is a very large wheeled vehicle that
uses the rotary motion of the tires to keep the flotation and give
propulsion at the same time with an aggressive tread. More
sophisticated versions can be found in US Patent 20070175380. These
designs have limitations as to its velocity and effectiveness as an
underwater craft.
[0041] U.S. Patent 20090200416 dealt with boundary layer propulsion
and control issues on airships and did so with an eye to the needed
distributed propulsion systems. It placed a "plurality of micro
propellers and riblets" in the boundary layers or boundary layer
separation areas but did not use a rotating hull or anything
similar to accomplish the desired ends. It did mention the
impracticality and implementation complexity of a great number of
power sources for low powered micro propulsion units that the
Active Hull contained herein is able to address.
[0042] Previous patents and literature have covered vortex
generation, arrays of VG, surface treatment both random and
specific, boundary layer propulsion, extracting energy from
vortices, and ships with large rotating structures. But none
accomplish the mission of propelling a rugged high velocity
underwater craft or device utilizing boundary layer forces and
distributed propulsion while avoiding the noise of cavitation.
SUMMARY
[0043] A submersible vehicle, apparatus and method utilizing the
Active Hull Platform to decrease drag and hydrodynamic noise while
increasing thrust through boundary layer vortex control and
distributed propulsion.
BRIEF DESCRIPTION OF DRAWINGS
[0044] FIG. 1 Exploded view showing embodiment of a Active Hull
before docking on Fixed Hull
[0045] FIG. 2 Detail shows a Blade on the Active Hull in Area (1)
and .psi.=45.degree.
[0046] FIG. 3 Detail shows a Blade in Area (2) on Fixed Hull and
.psi.=90.degree.
[0047] FIG. 4 shows an Active Hull docked with three detailed
sections delineated
[0048] FIG. 5A Detail cross section showing Area (1) and Area
(2)
[0049] FIG. 6A Detail cross section showing rotor and stator
embodiment
[0050] FIG. 7A Detail cross section showing ballast and balance
system with Surface Treatments
[0051] FIG. 8 embodiment utilizing counter rotating Active Hulls
and a fixed bow sonar system
[0052] FIG. 9 Left Handed VG array
[0053] FIG. 10 embodiment with large ram bow intakes and counter
rotating Active Hulls
[0054] FIG. 11A Detail elevation section shows VG, Blades, cilia
and Apparent Flow
[0055] FIG. 12 chart comparing different rotational velocities,
apparent flows and forces in the incremental X-Y plane
[0056] FIG. 13 Above water craft utilizing Active Hull
apparatus
[0057] FIG. 14 3d rendering showing corrugation and tubes to
generate and stitch down vortices
[0058] FIG. 15A Detail cross section showing Area (1), Area (2),
corrugation, vortices and tubes
[0059] FIG. 16 Detail showing tubes that connect Area (1) and Area
(2)
[0060] FIG. 17 top view of Variable Surface Treatment showing Blade
altering angle of attack
[0061] FIG. 18 top view illustrates morphing camber in Blade
[0062] FIG. 19A Detail side view of morphing camber in Blade in
FIG. 18
[0063] FIG. 20 shows flow strength and detection using strain
gauges on temporary installations
IDENTIFICATION OF DETAILS WITHIN THE DRAWINGS
[0064] 101 Active Hull [0065] 102 Sail or tail of a craft [0066]
103 the internal surface area or Skin of the embodiment [0067] 104
the external Skin of the Pressure Hull [0068] 105 Fixed Hull often
a Pressure Hull 102 herein [0069] 106 mechanical means of gears and
bearings [0070] 107 rotor--the rotating component built into and
made a part of the Active Hull making a large electrical motor
[0071] 108 stator--the stationary part of the large electrical
motor built into the Fixed Hull [0072] 109 Surface Treatment [0073]
110 fixed sonar (non rotating) [0074] 111 Vortex Generator (VG)
[0075] 112 traditional means of guidance and stabilizing including
horizontal and vertical stabilizers [0076] 113 external Skin of an
embodiment [0077] 114 permanent magnets that are part of a large
rotor 107 built into an embodiment [0078] 115 electro magnets, part
of the Fixed Hull stator assembly 108 [0079] 116 corrugated Surface
Treatment [0080] 117 flow detection and strain gauge showing
positive result from VG [0081] 118 flow detection and strain gauge
showing negative momentum [0082] 119 Boundary layer and boundary
layer flow [0083] 120 Apparent Flow vector or Bulk Flow [0084] 121
Left Handed vortices [0085] 122A ballast and balance tube purged
[0086] 122B ballast and balance tube filled [0087] 123 feeding
tubes which can create vortices, or another form of VG [0088] 124
return tubes or stitch down tube [0089] 125 bow tube or bow intake
[0090] 126 side thrusting anti torque system to oppose the torque
reaction a rotating hull [0091] 127 partition for balance or
ballast tubes [0092] 128 Variable Surface Treatment before change
in dimension or placement [0093] 129 Variable Surface Treatment
after change in dimension or placement [0094] 130 Blade [0095] 131
holes allowing a differential pressure on Blade forcing it to
collapse and change shape [0096] 132 forward sector that is paired
with a counter rotating aft sector 133 of an embodiment [0097] 133
aft sector that is paired with a counter rotating forward sector
132 of an embodiment [0098] 134 conventional propulsion system
[0099] 135 stern tube or exhaust [0100] 136 cilia like slender
protuberances to increase affect of vortices by absorbing energy
[0101] 137 rotor housing [0102] 138 above water Craft powered by 2
embodiments [0103] 139 variably pitched Blade [0104] 140 positioned
holes in Variable Blades that can morph camber [0105] A1 Area (1)
[0106] A2 Area (2) [0107] L distance from center of rotation of
embodiment to side thruster 126 [0108] V.theta. rotational velocity
of the embodiment [0109] Vf forward velocity of the Craft or
embodiment [0110] Vx 2 d incremental velocity vector in forward x
plane direction [0111] Vy 2 d incremental velocity vector in the y
plane from direction of rotation (V.theta.) [0112] Vx+Vy or Vxy is
the 2 d incremental Apparent Velocity vector adding Vx and Vy
[0113] Fx 2 dimensional (2 d) incremental vector force in the
forward direction of the Craft [0114] Fy 2 d incremental vector
force in the y plane or against incremental direction of rotation
[0115] Fxy Total 2 d incremental force combining Fx and Fy [0116]
Ux 2 d incremental flow velocity resulting from Vx or forward
motion [0117] Uy 2 d incremental fluid velocity resulting from
incremental rotational velocity Vy [0118] Uxy vector sum of
incremental 2 d fluid velocities combining Ux and Uy [0119] .psi.
is the angle formed by the Apparent Flow to axis of rotation or
forward direction
DETAILED DESCRIPTION
[0120] In the following detailed description of the invention,
numerous specific details are provided for a thorough understanding
of the invention. However, it will be appreciated by those skilled
in the art that the invention may be practiced without utilizing
every one of these details in any one embodiment. In addition,
well-known methods, procedures, materials, components and circuitry
have not been described in elaborate detail to avoid an unnecessary
obscuring of the invention. Many of these "means" are described by
those in "related art" and as such are included as if written
herein. However enough information is given so a Craft could be
built and methods could be followed using the information contained
herein along with state of the art methods and materials. The
reference materials included herein and simplified drawings
attached hereto and made a part hereof in absence of the ability to
present a working model are deemed the best way to concisely convey
the substance of the invention.
[0121] For the sake of brevity much of the fluid dynamic
terminology and underlying concepts are not restated herein and are
well known in the art. There are words listed in the terminology
section that the applicant would like to clarify or may have used
differently from the art due to the uniqueness of the system and
Craft. Words listed in the terminology section are capitalized when
used herein including the claims section. Whenever there is a
conflict between word usage in the art and the capitalized words
listed in this terminology section, the definitions of words listed
in TERMINOLOGY will take precedence and supersede those used in the
art.
TERMINOLOGY
[0122] Active Hull refers to one or more powered rotating bodies,
elements, shells, hulls or the like, whether that body is a
Pressure Hull or a Light Hull or both of any shape, length and
diameter, which rotates about a fore-and-aft axis that can be
hydrodynamically or rotationally balanced. An Active Hull may cover
wholly a Fixed Hull or partially, thereby exposing some elements of
that non rotating entity. An Active Hull will always have Surface
Treatments in Area (1) but may have either a Right Handed or Left
Handed rotation (counter-clockwise or clockwise) or both as in the
case of two counter-rotating Active Hulls.
[0123] Active Hull Platform is the formation and exploitation of
Apparent Flows and Surface Treatment in Area (1) or Area (1) and
Area (2) by utilizing an Active Hull.
[0124] Apparent Flow refers to the actual flow of fluid as seen by
an incremental area on or within the embodiment or Active Hull. It
is the resultant or vector sum of the rotational flows and axial
fore-aft flows. For example it is the fluid as it appears to a
Vortex Generator (VG) on an embodiment while the Craft is in
motion.
[0125] Area (1) refers to the area that contains the external Skin
of an embodiment or Active Hull, Surface Treatment if any, and the
external boundary layer and the area beyond as illustrated in FIG.
5A Detail.
[0126] Area (2) as depicted in FIG. 7A Detail is the area between
the Fixed Hull and the Active Hull and includes the internal
surface area or Skin of the Active Hull 103 and the external Skin
of the Fixed Hull 104 that lies beneath the Active Hull, and all
the area between the two including any Surface Treatment attached
to either.
[0127] Blade refers to a short wing whose purpose is to interact
with Apparent Flow but need not necessarily have some pitch or
angle of attack to Apparent Flow. A Blade's purpose is to create
thrust and is similar to traditional blades of a propeller in their
design in those stations more distal from the axis of rotation.
These Blades can exist in great numbers or arrays, be shorter in
length, be made from more flexible materials, have little or no
need for a "twist", and when distributed in great numbers have
smaller individual thrusts giving a smoother overall increased
impulse.
[0128] Boundary Layer Thrust refers to forces on or near the Skin
that are a result of vortices with some component of their momentum
nearest the Skin in the forward direction.
[0129] Bulk Flow is fully developed stream flow and for the
purposes of this application is the Apparent Flow beyond the
boundary layer and shear layer flow.
[0130] Craft is the sum of all systems that make a finished
independent water vessel that would include such systems required
to guide, propel, and limit drag whether traditional or some
embodiment of an Active Hull.
[0131] Fixed Hull is a hull, body or craft that has a general
velocity only in the fore-aft plane normally against the direction
of bulk fluid flow external to the craft. It refers to a hull that
has no flexibility in surfaces and does not rotate. In this
application a non rotating inner hull or body is an example of a
Fixed Hull as is the traditional hull of a craft.
[0132] Fixed when referring to a Surface Treatment is the apposite
of Variable Surface Treatment and allows for no alteration to size
or position of the Surface Treatment.
[0133] Left Handed vortex refers to a vortex downstream of a Vortex
Generator (VG) that has the rotation in the direction that fingers
of the left hand wrap when the thumb is pointed in the direction of
flow approaching the VG.
[0134] Light Hull is a hull that allows pressure to equalize
between inside and external surfaces so as to avoid the structural
requirements of a Pressure hull.
[0135] Pressure Hull refers to a hull that can structurally
withstand subsurface pressures and is generally dry on the inside
surfaces.
[0136] Right Handed vortex refers to a vortex downstream of a
Vortex Generator (VG) that has the rotation in the direction that
fingers of the right hand wrap when the thumb is pointed in the
direction of flow approaching the VG.
[0137] Skin refers to any surface of a craft, Fixed Hull or Active
Hull in Area (1) or Area (2) in contact with a fluid.
[0138] Surface Treatment refers to any surface condition or
conditions whether Fixed or Variable including a plurality of
various attachments, protrusions or valleys, of any size, shape, or
in any combination, joined to or made a part of the Skin in Area
(1) or Area (1) and Area (2). Area (1) Surface Treatment when
considered collectively with all other Surface Treatment on a Craft
within the Active Hull Platform must pass a functionality test of
both limiting traditional skin drag in a non random fashion and
increasing thrust in a distributed area over the majority of Skin
area in Area (1). This restriction is not placed on Surface
Treatment in Area (2) due to the unusual and controlled nature of
the flows in that area.
[0139] Trapped Vortices refer to vortices kept on or near the Skin
at least in part within the boundary layer by such means as
corrugations, cells, chambers and differential pressures.
[0140] Variable (as apposed to Fixed) when used in connection with
Surface Treatment refers to some alteration to size, shape,
concavities, convexities, placement, pitch or angle of attack.
[0141] Vortex Generator(s) (VG) refers to upstream structures in
Apparent Flow that create controlled vortices with specific
orientation of their axis of angular momentum in the boundary layer
downstream. These vortices are in contrast to random vortices
originating from random skin conditions such as dimples or
scales.
[0142] Referring now to the drawings to best explain the Active
Hull Platform contained herein, FIG. 1 is an exploded view that
depicts an embodiment that is an Active Hull 101 which is a Light
Hull that rotates about the fore-aft axis of a Fixed Hull 105 which
is a Pressure Hull for the embodiment. An Active Hull would have
the greatest advantage if the managed Apparent Flows created by
combining axial flows and specific rotational flows were exposed to
Surface Treatment 109 that could positively affect thrust and limit
drag in the area surrounding the Active Hull. The direction of
rotation is optional as long as the flow with correct angle of
attack to Surface Treatment 109 is maintained.
[0143] For simplicity in FIG. 1 the Light Hull embodiment is in the
shape of a cylinder with convex dished nose that is larger in
diameter and therefore able to fit over or be docked on an
underwater craft and Pressure Hull that is smaller in diameter also
the shape of a cylinder. The Fixed Pressure Hull within has
traditional means of guidance 112 and propulsion in the stern 134
and a sail 102 with side thruster 126.
[0144] The definition of Active Hull does not mandate physical
symmetry about the fore-aft axis but this application depicts only
bodies symmetrical about the fore-aft axis of rotation. However
variations including such things as shapes, cut outs, Surface
Treatment both Fixed and Variable, and pattern as viewed from
different perspectives could be asymmetrical in appearance and
still balance when rotating using hydrodynamic pressures from such
things as Variable Stabilizers or rudders in combination with the
balancing tubes described later. It is easy to see intuitively that
any form of an Active Hull as long as it is hydrodynamically
balanced at design angular velocities would satisfy the spirit of
this application and thereby be included herein.
[0145] The controlled rotational or angular velocity is introduced
into the embodiment as shown in FIG. 1 by supplying torque to the
embodiment. The torque could be supplied by normal mechanical means
106 of gears and bearings from a power source inside the Fixed Hull
105 as illustrated in prior art. The means chosen in a preferred
embodiment uses electromagnetic means within a rotor housing 137
made a part of the Active Hull as shown in FIG. 4. FIG. 6A Detail
illustrates such a means of applying power by utilizing permanent
magnets 114 hermetically sealed and built into a large rotor 107
attached to the Active Hull 101. The Fixed Hull has attached a
large armature stator ring 115 using brushless means to form the
electromagnets 108 to make the entire assembly a large
electromechanical motor.
[0146] The greater the torque applied to the embodiment the greater
the need for anti-torque forces to keep the Fixed Hull 105 within
from rotating. The Fixed Hull could have the torque of propellers
to help counter balance the torque of the embodiment in some
measure. Also in Area (2) A2 described later and illustrated in
FIG. 7A Detail, the circumferential flows over Surface Treatment
could provide a counter moment to the torque applied to rotate the
embodiment. For fine tuning purposes, it could also be aided by a
sail propeller or side thruster 126 shown in FIG. 1. The greater
the distance L as shown in FIG. 1 the anti torque side thruster is
from the fore/aft axis of rotation the less force required to
supply the anti-torque moment to the Craft thereby quieting the
Craft further. However in a preferred embodiment, the anti-torque
is mainly provide by using coupled Active Hulls rotating in
opposite directions as shown in FIG. 8, FIG. 10 and FIG. 13. An
Active Hull by definition is one or more bodies so even numbered
bodies could be set to rotate in opposite directions to fulfill
this need.
[0147] There is generally a need for ballast in underwater Craft
and with higher rotational velocities of an Active Hull there comes
the need for rotational balancing as well. Bearing loads would be
substantially reduced if the Active Hull embodiment is balanced by
a ballast and balance tube system coupled with hydrodynamic
balancing using blades or rudders. FIG. 5A Detail and FIG. 7A
Detail shows tubes purged 122A and filled 122B with tube partition
127 to contain and distribute the ballast as needed. Dynamic
rotational balancing could be accomplished by a computer aided
system of sensing and then filling or purging the tubes as needed.
These same or similar tubes can be used to affect buoyancy or
maintain neutral buoyancy.
[0148] Bearing loads are both radial and axial and could be managed
by purely mechanical means of roller and thrust bearings or
electromagnetic bearings or some combination of the two. Both
electromagnetic and mechanical bearings are well known in the art.
Axial loads on thrust bearings would be reduced if there were
similar thrusts provided by both the Fixed Hull and Active
Hull.
[0149] This invention alters large fluid flows relative to the
customary axial velocities encountered by a Fixed Hull on its
external surfaces. It does so without the disadvantages of systems
employing a plurality of fragile micro systems or noisy,
inefficient, piping and pumping systems with large Reynolds
numbers. The managed flows are a resultant of the forward velocity
and specific angular velocity of an Active Hull and can be seen by
Surface Treatment in Area (1) to give a distributed thrust. Area
(2) may also have managed flows that will be discussed later.
[0150] Area (1) A1 as depicted in FIG. 5A Detail and FIG. 7A Detail
contains all the area from external Skin 113 of the Active Hull 101
outward, including the external boundary layer, shear layer and the
area beyond in contact with the bulk or free stream flow of the
external environment. For the purposes of this application Bulk
Flow is generally the Apparent Flow. Area (2) A2 is the area
between the Fixed Hull and the Active Hull 101 embodiment and
includes the internal surface area or Skin 103 of the Active Hull
101, and the external Skin 104 of the inner Fixed Hull 105 covered
by the Active Hull, and all the area between the two as depicted in
FIG. 5A Detail and FIG. 7A Detail.
[0151] Surface Treatment has been defined in the terminology
section but it might help to clarify the definition by illustrating
what is not a Surface Treatment in Area (1). Augers, flights,
blades or foils are not Surface Treatment by themselves which is
easily seen when motionless and viewed from above. They don't cover
large portions of total skin areas of a craft and are not meant to
address boundary layer conditions that are the source of skin drag.
Smooth skin is an example that is not Surface Treatment if used by
itself or not used collectively with other Surface Treatment
because it does not address traditional skin drag and increase
thrust when used with an Active Hull. Rough skin, scales or dimples
may prove slightly advantageous to the formation of vortices in the
boundary layer but they don't satisfy the "non random" part of the
definition as they randomly energize the boundary layer and do not
form vortices with a specific axis of rotational momentum to aid in
thrust and limit drag. Therefore even if numerous augers or blades
were placed on rough or smooth skin they do not satisfy the
definition in Area (1) even though they might cover the majority of
a craft.
[0152] There are three basic types of Surface Treatment as defined
herein. The first general category discussed refers to devices
mechanically attached to or made a part of the Skin that create
vortices or are Vortex Generators (VG) and generally have a depth
within the boundary layer or shear layer. The second general type
of Surface Treatment is structures of or on the Skin or within the
Skin itself that can absorb, maintain, amplify, limit, dampen,
protect, trap or affect vortices or the forces and energies
imparted by vortices. Some examples are small cells, corrugations,
roughed surfaced or cilia. A third category of Surface Treatment
would be those that reach into the free stream or bulk flows beyond
the boundary and shear layer that have some benefit in those flows
such as Blades or Blade arrays.
[0153] Benefits of the Active Hull Platform from the first category
in Area (1) A1 will be focused on first with Area (2) A2 discussed
later. Vortex Generators (VG) 111 are shown in FIG. 1, FIG. 5A
Detail, FIG. 7A Detail, FIG. 9, FIG. 11A and FIG. 20 whose primary
function is to generate vortices with specific orientation within
the boundary layer make up the first category. They have depth h as
shown in FIG. 9 where h is equal to or less than the boundary layer
thickness 119 that varies with parameters that are unique to each
embodiment and are illustrated in FIG. 11A Detail elevation. A
plurality of VG each generating vortices make up arrays. These
arrays with specific placements and densities of VG are discussed
later and shown in FIG. 9 and FIG. 20.
[0154] FIG. 9 illustrates the affect of a low drag VG 111 from an
array of VG in Area (1) A1 similar to one depicted in U.S. Pat. No.
5,058,837 or US Patent 20080121301. The vortices 121 in FIG. 9
generated by the VG 111 on the embodiment have an axis parallel to
the Skin at any given point and transverse to the Apparent Flow
120. By producing Left Handed vortices 121 by the managed Apparent
Flow 120 the lower portion of the vortices next to the Skin has an
angular momentum orthogonal or 90.degree. to the Apparent Flow
120.
[0155] It is known in the art that generally the optimum angle of
attack of VG to flow is approximately 15.degree. as shown in FIG. 9
upper left hand corner. A constant flow direction or a constant
angle of attack to Fixed VG in Area (1) A1 is critical and can be
maintained with this invention by a constant ratio of V.theta./Vf
or altering the angular velocity with any increase or decrease in
forward velocity. If the angle of attack is varied too much, the VG
is nothing but a drag producing impediment or has little or no
affect at all.
[0156] It is important then to control the angle of attack to
Surface Treatment and this is best accomplished by managing
Apparent Flow. Managed Apparent Flow is done by velocity censors
and power control systems that maintain any desired ratio of
V.theta./Vf. As shown in FIG. 12 column A, a traditional fore-aft
flow Uf is the result of the fore-aft velocity Vf as with any Fixed
Hull underwater craft. A rotational flow U.theta. is added from the
rotary motion V.theta. inherent with the Active Hull. These two
flows combine to form an Apparent Flow. These flows can allow for a
constant flow direction over Fixed Surface Treatment by varying the
rotational velocity V.theta. to some constant ratio to the forward
velocity Vf or V.theta./Vf. It is well known in the art
methodologies of measuring and controlling such velocities by use
of sensors for both radial and forward velocities and applying
torque as needed to the Active Hull to maintain the desired ratio
of V.theta./Vf.
[0157] FIG. 12 gives a vector analysis of the incremental two
dimensional (2 d) velocities in the X-Y planes of Vf and V.theta.
which are Vx and Vy respectively. Column A shows Fx as an
incremental drag force found on a traditional hull apposing the
forward velocity Vf. Column A Row 1 shows V.theta.=Vf and Row 2
shows V.theta.=2Vf or the rotational velocity doubles in Row 2 with
the same fore-aft velocity. Column B illustrates the 2 d
incremental velocities of Vx+Vy or Vxy when Vx is the incremental 2
d forward velocity in the X plane and Vy is the incremental 2 d
velocity in the direction of rotation in the Y plane.
[0158] FIG. 12 Column C illustrates the flows generated from the
velocities in Column B which when combined is the incremental
Apparent Flow 120. These flows are Ux and Uy or Uxy when combined
at some angle `.PSI.` to the axis of rotation. The angle .psi. as
shown in Column C increases as the ratio V.theta./Vf increases as
shown by the three solid arrows in Row 1 for the direction of the
Apparent Flow 120 when V.theta.=Vf and three dashed arrows in Row 2
to show the direction when V.theta.=2Vf. Column C therefore
illustrates graphically what can be seen intuitively, as the ratio
of V.theta./Vf increases, the resulting flow vectors become more
perpendicular to the forward direction of the embodiment.
[0159] FIG. 9 shows that the momentum of vortices 121 closest to
the Skin is orthogonal to the Apparent Flow 120. FIG. 12 Column D
compares the forces on the Skin from the momentum of the vortices
121 as the flow vectors in Column C become more perpendicular to
the fore-aft direction of the embodiment. Incremental negative drag
vortices -(-Fx) can be written as a positive force in the forward
direction and shown as Fx in Column D. Therefore the 2 d momentum
of the vortices formed when nearest the Skin can be broken down
into incremental forces applied to the Skin of Fx and Fy in the
simplified condition of no slippage. Slippage and increasing
frictional affects from vortices is dealt with later. Fx is the
resulting incremental force from vortices in the forward direction
of the embodiment as the vortices 121 loses momentum to the nearest
incremental area of Skin. The change in momentum from the vortices
produced from Row 1 to Row 2 in FIG. 12 shows an increase in the
incremental force Fx with a decrease in incremental force Fy as
V.theta. increases relative to Vf.
[0160] Column D shows the related positive Skin forces Fx when the
rotational velocity V.theta. increases relative to forward velocity
Vf on an embodiment as shown in Column A, Row 1 and Row 2
respectively. The constant flow direction maintains beneficial
forces from vortices in the forward direction (negative drag)
facilitating dispersed areas of Boundary Layer Thrust even if the
forward velocity is increased, decreased or kept constant during
cruise conditions.
[0161] There are numerous benefits of putting the center of effort
further forward on a Craft but with the traditional fixed hull
craft they must be ignored as too costly because of the increased
skin drag after the forward propulsion system due to the disruption
of laminar flow. Here the more forward center of effort from
accumulated Boundary Layer Thrust which is the result of the sum of
all the beneficial incremental forces Fx comes with an added
benefit of decreasing skin drag.
[0162] Summarizing, skin drag is a result of friction and vortices
formed by that friction. It is normally considered a negative force
or a positive force in a negative direction which could be stated
as -Fx as shown in Column A. However, the direction of -Fx can be
altered with the addition of rotational flow and Surface Treatment
that is introduced by the Active Hull. These tangential or
repositioned flows respond to selected VG with an appropriate angle
of attack to produce vortices with some incremental momentum
nearest the Skin in the forward direction of the Craft to give a
-(-Fx) or +Fx and Fy. Fy can be overcome by additional torque
supplied by the power source to the Active Hull and not be a burden
to other more traditional propulsion systems normally found in the
stern.
[0163] Therefore the Active Hull Platform is utilizing the momentum
forces in vortices for an incremental forward Boundary Layer Thrust
which is doing far more than just energizing the boundary layer to
randomly break up or slow the formation of von Karman vortices.
However these specific non random vortices would additionally
interfere with the formation of von Karman vortices as they are
interjecting energy into the boundary layer that oppose the
formation of drag causing vortices.
[0164] As the axis of angular momentum of the vortices approaches
perpendicularity to the direction of forward motion, an even larger
force in the forward direction of the embodiment is possible.
However, as the velocity of the Craft in the forward direction is
increased, the greater the need for an increased angular velocity
for the Active Hull in order to preserve a constant angle of attack
to the Surface Treatment without resorting to a myriad of Variable
Surface Treatments.
[0165] The second category of Surface Treatment considered herein
to illustrate the advantages of the Active Hull Platform are
structures of the Skin or within the Skin itself that can among
other things absorb, maintain, amplify, limit, dampen or affect
vortices or the forces and energies imparted by vortices. Some
Surface Treatment that fall into this category are surface
roughness, channels, shelves, cells, tubes, concavities,
convexities, and slender protuberances or cilia on the Skin that
can absorb Fx and limit the effect of Fy as developed in FIG. 12.
Examples in previous patents are U.S. Pat. Nos. 4,671,474,
005417391 and 3,578,264.
[0166] The example used for the purposes of this application are
cilia 136 which are illustrated in FIG. 11A Detail elevation. They
aid in capturing the momentum of the vortices generated in the
area. With their increased surface area and flexibility they can
follow the motion of the vortices nearest the Skin and absorb and
amplify the energies imparted by the controlled vortices discussed
above.
[0167] Another example is shown in FIG. 14 where the surface has
corrugations and tubes that link both areas A1 and A2 and
establishes an interaction between the two areas when the
embodiment is a Light Hull. This is also an alternate method of
producing and maintaining the angular momentum of vortices 121
generated upstream by feed tubes 123 shown in FIG. 16 Detail and
stitched down return tubes 124 by the porting of fluid through and
between the two areas A1 and A2. Stitching down vortices is
discussed in U.S. Pat. No. 4,671,474 and is a form of Trapped
Vortices.
[0168] The outflow feed and return tubes port fluid by utilizing
the higher ram pressures against scuppers and lower pressures
affected by Bernoulli principle as shown in FIG. 15A Detail to
create the needed flows. This system could create vortices without
the strict adherence to some ratio of Vf/V.theta. but would also
necessitate maintenance problems keeping the tubes clear of debris.
Its main purpose for being mentioned here is that there are
additional degrees of freedom available with the Active Hull
Platform which is interaction and relative motions of the two
bodies.
[0169] The third group of Surface Treatment utilized herein to show
the positive affects of the Active Hull Platform have a primary
purpose enhancing thrust in the bulk flows outside the boundary
layer. Although they might inadvertently affect boundary layer
flow, their main purpose is to interact with bulk flows beyond the
shear layer. Long flagella like whips or slender flexible even
chain like protuberances that are outside the boundary layer would
fall into this category but the example used herein to illustrate
the advantages of this Active Hull Platform is Blades 130. They are
shown in several drawings such as FIG. 1, FIG. 2 Detail, FIG. 3
Detail, and FIG. 11A Detail in both areas A1 and A2 as the art is
fully developed and well studied for Blades.
[0170] Control of flow velocity in Area (1) A1 is the same for all
categories of Surface Treatments. Therefore the methodology of
controlling fluid vector direction and speed won't be repeated
again here and can be found above as it applies to Vortex
Generators.
[0171] Where VG can be placed with an angle of attack of 15.degree.
to Apparent Flow, Blades may also be placed with some angle of
attack or pitch to Apparent Flow to increase mass flow and thereby
increase thrust. Depending upon design criteria and acceptable
hydrodynamic noise levels, Blades could alternately be placed
parallel to Apparent Flow and have no angle of attack and rely
solely on lift for thrust thereby limiting noise.
[0172] As can be seen in FIG. 1, Blades in Area (1) A1 can be
placed in a direction parallel to Apparent Flow 120 that allow
forward convex surfaces or driving faces to facilitate forward
thrust. It can be seen in FIG. 2 the Blades 130 attached to the
Active Hull 101 are at angle .psi.=45.degree. to the axis of
rotation which is the expected Apparent Flow 120 if Ux/Uy=1. (See
FIG. 12 Row 1)
[0173] FIG. 2 Detail shows the vector diagram that illustrates
incremental Blade forces for Area (1) A1 ignoring frictional forces
on the Blade. Fx being the force in the direction of forward motion
of the Craft and Fy the force apposing the direction of angular
velocity V.theta.. It is easily seen that the greater the Fy force
the less efficient the Blades will be. Therefore, the greater
V.theta. is relative to Vf (or the larger the ratio V.theta./Vf)
the more efficient the use of Blades in Area (1) is going to be as
Fy approaches zero. Blades in Area (2) are discussed later.
[0174] The Active Hull Platform employs relatively short Blades or
Blade arrays over large surface areas and can exploit large bulk
flows over the embodiment thereby lessoning the opportunity for
cavitation. A large benefit of the Active Hull Platform is that
speeds in the forward direction will not have to originate solely
from a centralized propulsion system. Therefore velocity will not
be sacrificed in order to avoid hydrodynamic noise provided that
the Blades are designed with the appropriate camber to accommodate
the design flows intended or they are Variable in nature as
discussed later. They may also be designed with a slight rake as
shown in FIG. 11A Detail so as to slip debris that comes their
way.
[0175] If increased mass flow providing additional thrust is
acceptable and desired a Blade could be designed as is known in the
art that would provide same. By altering the ratio of V.theta./Vf
and taking advantage of the altered Apparent Flows to the pitch
angles of the Blades an increased mass flow may be produced. Once
acceleration in the forward direction is completed to some new
faster speed, the Craft may once again return to a ratio of
V.theta./Vf that is parallel to the pitch angle of the Blades.
[0176] Shorter Blades a long distance away from the theoretical
axis of rotation would allow for a very uniform structure with
negligible twist required. These numerous shorter Blades would also
not be subject to the large loading that centralized propeller
propulsion sees and is therefore in a position to be constructed of
a variety of materials that may enhance their usage further as
discussed later in Variable Surface Treatments. There is also the
benefit of putting the center of effort further forward on a Craft
without the disadvantages of increased turbulence aft because the
Blades can be mounted parallel to fluid flow and have little effect
on laminar conditions especially when used in conjunction with VG
that can also provide thrust and energize the boundary layer to
counter coalescing drag vortices.
[0177] The larger diameter of a traditional subsurface craft the
larger the form drag and skin drag. However with the larger
embodiments of an Active Hull there come advantages that help
nullify these such as a larger overall net thrust from the
increased surface areas that provide thrust. Another advantage with
increased diameters is the decreased probability of vortex momentum
breakaway as the incremental surface area exposed to fluid
approaches a flat plane.
[0178] Focusing now on Area (2) A2 as seen in FIG. 5A Detail and
FIG. 7A Detail. Area (2) may be sealed by use of mechanical seals
or face seals commercially available and left dry. This condition
would have the Active Hull be a Pressure Hull. With rotational
velocities found appropriate for water Craft, Surface Treatment in
Area (2) would be superfluous according to the art but there would
also not be drag surfaces within Area (2). There is also the
opportunity for sound attenuation to be placed between the Active
Hull and the inner Fixed Hull.
[0179] When fluid is allowed to flow inside so as to equalize
pressure on both sides of the Active Hull, an Active Hull could be
a Light Hull. The area could be closed or nearly so with negligible
through flow and effectively filled with special fluids or
additives to affect such properties as friction, sound attenuation
and/or magnetic flux densities. Such Treatment might include
surfactants, polymers, and plasma or ion production to reduce drag
between the two bodies. See U.S. Pat. No. 4,812,251. With
negligible through flow the constant addition of specialized
additives could also be minimized or nearly eliminated.
[0180] If Area (2) had negligible axial flows or only those flows
needed to equalize pressure, it would replicate closely the
Couette-Taylor system (Ref: Lathrop, Fineberg, & Swinney Volume
46). With the Active Hull the outer cylinder is in rotation and is
the driving cylinder rather than the inside Fixed Hull. Therefore,
the centrifugal force against the driving Active Hull would
increase the frictional affects and accelerate the fluid in Area
(2) at an even faster rate than if the inside cylinder were the
rotating force as in the Couette-Taylor system thus giving an
advantage to the Active Hull.
[0181] If appropriate Surface Treatment such as cilia or surface
roughness were added to surface 103 as shown in FIG. 7A Detail, it
would increase the traction and therefore increase acceleration of
flow even more to compensate for energy lost to friction over Skin
104 and Surface Treatment on Skin 104 such as Blades 130. At cruise
the fluid and surface 103 are traveling at similar velocities.
However, the energy stored in this rotating fluid could be
converted to forward thrust or forward lift if allowed to flow over
such Surface Treatment as Blades 130 on surface 104 with their
convex surfaces facing forward.
[0182] In open through flow situations in Area (2), unstable flows
continue as Reynolds numbers increase. In a negligible flow
scenario in Area (2) a Light Hull at high Reynolds numbers >10
4.sup.th has great instabilities in vortices formed so as to limit
their coalescing affect as those vortices become too fragmented.
(Ref: Lathrop, Fineberg, & Swinney Volume 46) These Reynolds
numbers are quickly and easily reached within Area (2) with
negligible through flow even with low rotational velocities of an
Active Hull. It is easily seen then that the flows would quickly
result in no turbulent Taylor vortices between the two cylinders
making it an efficient system should the rotating fluid be utilized
with the Active Hull Platform and translated into linear motion
with Surface Treatment such as Blades on surface 104.
[0183] The definition of Surface Treatment allows for Blades alone
provided they are placed in Area (2) and not Area (1). The exploded
view of FIG. 1 shows Surface Treatment 109 of type Blades 130
attached to the Fixed Hull 105 on Skin 104. After the embodiment is
docked the Blades are covered and within Area (2) A2. The Blades on
the Fixed Hull 105 are perpendicular to fore-aft axis of rotation
and are parallel to the rotational flow or Apparent Flow 120 with
Ux=0. As discussed above there would be a vigorous flow in a
direction perpendicular to forward motion if negligible through
flow existed.
[0184] The placement of Blades in Area (2) A2 in FIG. 1 is in a
direction parallel to Apparent Flow 120 that is purely
circumferential in the case of negligible through flow. This flow
allows forward driving convex faces to be placed directly forward
to parallel the axial movement of the Craft. FIG. 3 Detail shows
the vector diagram that illustrates the forces on Blades for Area
(2) A2 with negligible through flow. Fx being the force in the
direction of forward motion of the Craft and Fy is the force in the
direction of fluid motion. Fy has a frictional force omitted in
this simplified example and is countered by the application of
continued torque on the embodiment and not overcome by additional
thrust from a centralized propulsion system in the stern.
[0185] In Area (1) the direction of flow as seen by Surface
Treatment can be controlled by managing the rotation of the
embodiment and more particularly the ratio Vf/V.theta.. Area (2)
has the added benefit of controlling the through flow or mass flow
which gives Area (2) an added degree of freedom for managing
Surface Treatments and drag forces.
[0186] Area (2) has the potential of one body moving relative to
another so it also has the opportunity of creating mass flows
either as a positive displacement pump with one body moving axially
relative to the other, or in a rotational plane as is illustrated
herein with the preferred embodiment utilizing turbine fins or
Blades, or both. Area (2) has the potential for combined rotational
flows and fore-aft axial flows (through flow) if fluid were allowed
to enter and exit the area in an appreciable manner. These
increased mass flows or thrusts could easily be ported to give some
measure of guidance.
[0187] Hatches could easily control the through flow In Area (2)
and could be negligible, ram pressure flow, or increased flows to
aid in mass flow propulsion. FIG. 8 and FIG. 10 show an embodiment
with portals or intakes 125 and stern tubes or exhausts 135.
[0188] Bow intakes as shown in FIG. 10 can interfere with sonar
installations. FIG. 8 shows an embodiment with Fixed Hull sonar
installation exposed and bow intakes 125 aft of the sonar
installation. The Active Hull rotates aft of the fixed sonar
installation.
[0189] Surface Treatment may be either Fixed or Variable as defined
herein so as to alter some aspect of their dimensionality or
positioning. U.S. Pat. No. 6,427,948 illustrates a Variable Vortex
Generator. FIG. 17 shows a Variable Blade, with an individual
mechanical change to position or pitch relative to flow in a before
128 and after 129 positioning. FIG. 18 and FIG. 19A Detail
illustrate a change in camber utilizing deformation of materials
sensitive to flow velocities made of a semi rigid material such as
HDPE or the like and does not require an individual mechanical
control over each Blade. With the resiliency of these materials as
flow velocities decrease they would regain their original shape or
camber.
[0190] Morphing wings are well documented in the art and can
include more flexible or pliable material that can morph camber by
increasing or decreasing rib length of the Blade. In the case shown
in FIGS. 18 and 19 Detail Bernoulli's principle is utilized over
strategically placed holes 140 or slots to lower the pressure
inside the Blade to more than compensate the lower pressures on the
driving face of the Blade on the external surface. This would not
be possible with the stresses put on large propeller blades in a
centrally located propulsion system. A preferred embodiment evading
hydrodynamic noise would use the deformable or morphing Blade that
would decrease camber as the flow velocities increase so as to
eliminate cavitation and noise at the high flows of maximum design
velocities.
[0191] It can be seen that some modification of Surface Treatment
could be advantageous particularly with guidance or acceleration in
limited areas as shown by Variable Blade 139 near the bow in FIG. 1
and is considered to be part of the Active Hull Platform contained
herein.
[0192] Little space will be devoted to a large plurality of
individually electro-mechanically controlled Variable Surface
Treatment that cover great areas of a Craft because of the
impractical nature of supplying power and control over that many
mechanical devices in a larger Craft. However within the scope of
the Active Hull Platform individually controlled Variable Surface
Treatment could be accomplished with mechanical and
electro-mechanical means to benefit thrust and control over the
Craft such as larger variably pitched bow blades and are therefore
included herein.
[0193] It's important to note that by using Apparent Flows to keep
a constant flow direction, much of the need for individually
controlled Variable Surface Treatment is avoided but as seen above
with the example of the morphing Blade, there are Variable Surface
Treatment when used with the Active Hull Platform that are
practical to implement. Other morphing or changing Surface
Treatment that takes advantage of fluid speeds or centrifugal
forces could be a subject of future applications.
[0194] The art of vortex generation in each design is unique to
that embodiment. VG placement and density is affected by such
things as Reynolds number, configuration of VG including VG height
and type, diameters and velocities of hulls and surrounding
locations of other structures and other Surface Treatments. The
Active Hull Platform is a method or system that is the amalgamation
of a managed Active Hull, Surface Treatments and design
criteria.
[0195] From Investigation of Vortex Generation Dayton A Griffin
December 96 RNEL for non random surface VG the data shows an
optimum placement for Reynolds numbers in the magnitude of E6 to be
10h where h=depth of VG and s=distance apart or spacing of VG as
shown in FIG. 4. At lower Reynolds numbers a more sparse density
was appropriate and in most cases a staggered array (See FIG. 9)
showed better results. Reynolds numbers can be greater than E6 with
an embodiment making the placement denser or closer together than
10h. To give some sense in a dimensional world, h would likely be
in the approximate range of 1 centimeter depending upon the
Reynolds numbers and the desired embodiment so they could be
constructed to withstand abuse and still maintain their
functionality.
[0196] Although general knowledge of placement is known in the art,
optimum placement of Surface Treatment is best found through
experimentation on an actual Craft of similar size, speed, Skin
conditions and placement of other structures that may cast a flow
shadow. This can most easily be accomplished by temporary
applications of arrays utilizing suction or magnetic pads
containing Surface Treatments. Placement of such devises as
described in U.S. Pat. No. 6,963,810 B2 on an embodiment by
utilizing a quick installation and removal as described in U.S.
Pat. No. 5,265,069 or the like would give an optimum placement for
any given embodiment, location and Reynolds number.
[0197] Flow strength and detection using strain gauge capability
will show direction and momentum intensity of vortices produced
within the boundary layer as shown in FIG. 20. These results could
be transmitted and recorded to a computer to show optimum placement
of Surface Treatment which are VG 111 in this embodiment. Positive
detection gauge 117 shows momentum in a positive direction with
respect to Vf and a gauge showing a negative result 118 is shown in
a near by area in FIG. 20.
[0198] This application thus far has only illustrated the Active
Hull as a Craft but it can also be used as an apparatus or device.
One such apparatus or power pod can power and maintain a surface or
above surface craft. FIG. 13 illustrates an Active Hull apparatus
as a means to reduce drag and provide propulsion on an above water
vessel. U.S. Pat. No. 3,730,123 High Speed Ship with Submerged Hull
is a similar system that doesn't utilize an Active Hull as
described herein.
* * * * *
References