U.S. patent number RE33,158 [Application Number 06/713,716] was granted by the patent office on 1990-02-06 for fluidic oscillator with resonant inertance and dynamic compliance circuit.
This patent grant is currently assigned to Bowles Fluidics Corporation. Invention is credited to Peter Bauer, Ronald D. Stouffer.
United States Patent |
RE33,158 |
Stouffer , et al. |
February 6, 1990 |
Fluidic oscillator with resonant inertance and dynamic compliance
circuit
Abstract
The fluidic oscillator consists of a resonant fluid circuit
having a fluid inertance and a dynamic fluid compliance. The
inertance is a conduit interconnecting two locations of a chamber
on each side of a working fluid jet issuing into one end of the
chamber, the inertance conduit serving to transfer working fluid
between the two locations. Through one or more output orifices
located approximately at the opposite end of the chamber, the fluid
exits from a chamber exit region which is shaped to facilitate
formation of a vortex (the dynamic compliance) from the entering
fluid. The flow pattern in the chamber and particularly the vortex
in the chamber exit region provide flow aspiration on one side and
surplus of flow on the opposite side of the chamber, which effects
accelerate and respectively decelerate the fluid in the inertance
conduit such as to cause reversal of the vortex after a time delay
given by the inertance. The vortex in the chamber exit region will
thus cyclically alternate in velocity and direction of rotation to
direct outflow through the output orifice such as to produce a
cyclically repetitive side-to-side sweeping stream our spray
pattern whose direction is determined, at an instant in time, as a
function of the vectorial sum, at the output orifice, of the
tangential vortex flow spin velocity vector and the static pressure
vector as well as the dynamic pressure component, both directed
radially from the vortex. By changing these parameters by suitable
design measures and operating conditions and by appropriately
configuring the oscillator, sweep angle, oscillation frequency,
distribution, outflow velocity, break up into droplets, etc. can be
readily controlled over large ranges.
Inventors: |
Stouffer; Ronald D. (Silver
Spring, MD), Bauer; Peter (Germantown, MD) |
Assignee: |
Bowles Fluidics Corporation
(Columbia, MD)
|
Family
ID: |
21792222 |
Appl.
No.: |
06/713,716 |
Filed: |
March 19, 1985 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
019250 |
Mar 9, 1979 |
04231519 |
Nov 4, 1980 |
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Current U.S.
Class: |
239/589.1;
137/826; 137/835 |
Current CPC
Class: |
B05B
1/08 (20130101); F15C 1/22 (20130101); Y10T
137/2234 (20150401); Y10T 137/2185 (20150401) |
Current International
Class: |
B05B
1/02 (20060101); B05B 1/08 (20060101); F15C
1/22 (20060101); F15C 1/00 (20060101); B05B
001/08 (); B05B 001/34 (); F15C 001/22 () |
Field of
Search: |
;239/4,101,102,589,590,DIG.3,102.2,589.1
;137/810,811,826,829,832,835,836,839 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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181013 |
|
Dec 1979 |
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JP |
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1007881 |
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Oct 1965 |
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GB |
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Primary Examiner: Kashnikow; Andres
Attorney, Agent or Firm: Zegeer; Jim
Claims
What I claim is:
1. A fluidic oscillator having a chamber, an inlet opening for
issuing a jet of working fluid into said chamber, and an outlet
opening for issuing working fluid from said chamber into the
ambient environment, characterized by a fluid inertance flow
conduit transferring working fluid between first and second
locations on opposite sides of said jet and near said inlet opening
in said chamber, and a dynamic compliance in the form of a vortex
region defined between sidewalls of said chamber which generally
converge towards said outlet opening and near said outlet opening
such that working fluid in the jet forms in said vortex region a
vortex which alternately flows in opposite directions, the vortex
alternately aspirating fluid from and supplying fluid to said first
and second locations in opposite phase and thereby through said
inertance in alternately opposite directions.
2. The oscillator according to claim 1 further including an
adjustment for changing the inertance of said flow conduit. .[.3.
The oscillator according to claim 1 further including a pressure
control device for permitting adjustment of the static working
fluid pressure in said vortex region to change the frequency and/or
outlet spray pattern of said oscillator..]. .[.4. The oscillator
according to claim 1 further including a first adjustment for the
oscillator frequency in the form of an adjustment for the length of
said inertance flow conduit, and a second adjustment for the
oscillator frequency in the form of a control of the static
pressure in said vortex region, the effect on oscillator frequency
of the first and second adjustments being multiplicative..]. .[.5.
A showerhead employing the oscillator of claims 1, 2, 3, or 4..].
.[.6. The oscillator according to claims 2 or 4 wherein the
inertance flow conduit is the closed end of a hollow cylinder open
at one end and closed at the other end with a cylindrical piston
axially slidable therein, the closed end of the cylinder being of
greater diameter than the portion of the cylinder immediately
adjacent thereto and being pressure sealed therefrom, whereby the
axial movement of the piston in the cylinder varies the volume and
the shape of the volume of the closed end and hence the
inertance
thereof..]. .[.7. The oscillator according to claims 3 or 4 wherein
control of static pressure in the vortex region is provided by a
valve which controllably supplied pressurized working fluid to said
vortex region through an opening therein..]. .[.8. A fluid spray
device in the form of a fluidic oscillator having a power nozzle
issuing a jet of working liquid into a chamber, an outlet opening
for issuing working liquid spray from said chamber, and means in
said chamber for oscillating the issued liquid spray back and forth
transverse to the general direction of the jet, said device being
characterized by means for adjusting the shape of the pattern
formed by said issued spray by controlling the static pressure in
said chamber downstream of said nozzle..]. .[.9. The fluidic spray
device according to claim 8 wherein said means for adjusting is a
valve for supplying pressurized working fluid into said chamber
through another opening therein..]. .[.10. The fluidic spray device
according to claim 8 wherein said chamber includes a vortex region
in which a vortex flow of said working fluid alternately flows in
opposite directions at the frequency of said oscillator and wherein
said means for adjusting includes an opening in said chamber at
said vortex region and means for controllably admitting pressurized
working fluid into said vortex region
through said opening..]. 11. A fluid spray device comprising:
a chamber;
inlet means for issuing a jet of working fluid into said
chamber;
outlet means for issuing working fluid from said chamber in a flow
pattern and direction determined by the static pressure and flow
velocity of working fluid in said chamber;
dynamic compliance means in the form of sidewalls which converge
toward said outlet opening and near said outlet opening for
establishing a vortical flow of the working flow issued into said
chamber; and
fluid inertance means for cyclically reversing said vortical flow
between first and second flow directions, said fluid inertance
means interconnecting first and second locations in said chamber on
opposite sides of said jet proximate said inlet means such that
vortical flow in said first flow direction aspirates fluid from
said fluid inertance means at said first location and feeds fluid
into said fluid inertance means at said second location, and such
that vortical flow in said second direction aspirates fluid from
said fluid inertance means at said second location and feeds fluid
into said fluid inertance means at said first location, said fluid
inertance means including means establishing a flow inertia for
delaying changes in flow conditions through said fluid inertance
means in response to differential pressure changes across said
first and second
locations. 12. The spray device according to claim 11, further
comprising frequency control means for permitting selective control
of the frequency
at which said vortical flow reverses directions. 13. The spray
device according to claim 12 wherein said fluid inertance means
comprises a flow passage of small cross-section extending between
said first and second locations, and wherein said frequency control
means comprises means for
selectively adjusting the length of said flow passage. .[.14. The
spray device according to claim 12 wherein said frequency control
means comprises further means for selectively controlling the
static working fluid pressure in said vortical flow..]. .[.15. The
spray device according to claim 14 wherein said further means
comprises valve means for supplying pressurized fluid to said
chamber at a location downstream of said inlet means..]. .[.16. The
spray device according to claim 15 further comprising means for
simultaneously adjusting the flow rates of working fluid through
said inlet means and said vale means..]. .[.17. The spray device
according to claim 11 wherein said fluid inertance means comprises
a flow passage of small cross-section extending between said first
and second locations, said device further comprising first and
second independently adjustable frequency control means having a
combined multiplicative effect on the frequency at which said
vortical flow reverses directions, said first frequency control
means comprising means for selectively adjusting the length of said
flow passage, said second frequency control means comprising means
for selectively controlling the static pressure in said chamber..].
.[.18. The spray device according to claim 11 wherein said fluid
inertance means comprises the closed end of a hollow cylinder open
at one end and closed at the other end and having a cylindrical
piston axially slidable therein, the closed end of the cylinder
being of greater diameter than the portion of the cylinder
immediately adjacent thereto and being pressure sealed therefrom,
whereby the axial movement of the piston in the cylinder varies the
volume and the shape of the volume of the closed end and hence the
inertance thereof..]. .[.19. The spray device according to claim 11
wherein said outlet means includes an opening in said chamber
positioned at the periphery of said vortical flow to issue working
fluid from said vortical flow in the form of a swept jet which
oscillates between extreme diverging sweep positions as a function
of the changing vortical flow velocity and static pressure within
said chambers, said device further comprising control means for
selectively controlling the angle between said two extreme sweep
positions..]. .[.20. The spray device according to claim 19 wherein
said control means comprises means for selectively varying the
static pressure in said chamber from a location downstream of said
inlet means..]. .[.21. The spray device according to claim 11
wherein said outlet means comprises a plurality of outlet openings
for issuing individual spray patterns of working fluid from said
chamber..]. .[.22. The combination according to claim 11 comprising
two of said spray devices and further including further means for
synchronizing the two spray devices in frequency of vortical flow
reversal, said further means comprising:
a first flow conduit interconnecting said first locations in said
two spray devices; and a second flow conduit interconnecting said
second locations in said two spray devices..]. .[.23. The
combination according to claim 22 disposed in a shower head..].
.[.24. The combination according to claim 11 wherein a plurality of
said spray devices are part of a spray assembly, comprising;
a common supply passage for delivering working fluid to all of said
plurality of spray devices, said spray devices being positioned
at
locations along said common supply passage and oriented to issue
outlet spray generally toward a common location..].
Description
BACKGROUND OF THE INVENTION
The present invention relates to improvements in fluidic
oscillators and particularly to a novel fluidic oscillator capable
of providing a dynamic output flow of a broad range of properties
which is obtainable by simple design variations and which can be
further readily controlled during operation by appropriate
adjustment means to achieve extensive performance flexibility, thus
facilitating a wide variety of uses.
Fluidic oscillators and their uses as fluidic circuit components
are well known. Fluidic oscillators providing dynamic spray or flow
patterns issuing into ambient environment have been utilized in
such manner in: shower heads, as described in my U.S. Pat. No.
3,563,462; in lawn sprinklers, as described in U.S. Pat. No.
3,432,102; in decorative fountains, as described in U.S. Pat. No.
3,595,479; in oral irrigators and other cleaning apparatus, as
described in U.S. Pat. No. 3,468,325; (also see U.S. Pat. Nos.
3,507,275 and 4,052,002, etc.). Most of these oscillators are
constructed to produce outflow patterns which are suitable only for
use in the specific apparatus for which they were designed and lack
flexibility and adjustability for use in other applications. In
most applications for prior art oscillators it has been found that
performance is adversely affected by relatively small dimensional
variations in the oscillator passages and chamber. It has also been
found that most prior art oscillators require configurations of
relatively large dimensions to satisfy particular performance
requirements such that they are barred from many uses by practical
size restrictions. Furthermore most prior art oscillators have not
had the capability for extensive in-operation adjustments of
performance characteristics to fulfill numerous uses necessitating
such adjustment capabilities.
Many prior art fluidic devices, such as in U.S. Pat. Nos. 3,016,066
and 3,266,508, have relied in operation on well established fluidic
principles, such as the Coanda effect. It is, in my opinion, this
reliance on such well-known effects which has brought about the
aforementioned limitations and disadvantages.
It is an object of the present invention to provide a fluidic
oscillator which functions largely on different principles than
previous fluidic oscillators and, therefore, overcomes the
aforementioned limitations and disadvantages, and provides
capabilities hitherto unavailable to meet application requirements
for which prior art fluidic oscillators have not been suited.
It is another object of the present invention to provide a fluidic
oscillator whose outflow pattern performance can be varied over
broad ranges by simple design measures.
It is yet another object of the present invention to provide a
fluidic oscillator which is relatively insensitive to dimensional
manufacturing tolerances and dimensional variations resulting from
its operation.
It is a further object of the parent invention to provide a fluidic
oscillator of relatively small dimensions to meet practical size
restrictions of many applications. For example, where as most prior
art fluidic oscillators require, for satisfactory functions,
lengths, between the feed-in of supply fluid and the final outlet
opening of at least 10 (but more than 12 to 20 and in some cases as
much as 30) times the respective supply feed in nozzle widths, the
present invention fluidic oscillator operates already with such
relative lengths of as little as 5. Similarly, whereas most prior
art fluidic oscillators require relative widths for the total
channel configuration of at least 7 or more, the present invention
oscillator configuration spans a relative width of 5 or less in
many applications. One can readily appreciate the application
advantages offered by such practical size reductions in the total
oscillator configuration area to about one half or one third.
It is yet another object of the present invention to provide a
fluidic oscillator allowing and facilitating extensive adjustments
of performance characteristics over broad ranges during operation.
Oscillation frequency and angle of output flow sweep pattern and,
therefore, also such dependent characteristics as waveform,
dispersal distribution, velocity, etc. may be adjusted by simple
means such that performance can be varied and adapted to changing
requirements during operation. Furthermore, it is also an object of
the present invention to provide a fluidic oscillator whose
performance may be adjusted or modulated continuously in the
aforementioned characteristics by externally applied fluid control
flow pressure signals. By way of an example, tests have been
performed with experimental models of fluidic oscillators of the
present invention, which have shown a frequency adjustment range of
over one octave and an output sweep angle adjustment range from
almost zero degrees to over ninety degrees by application of an
external fluid pressure flow to the oscillator control input
connection with control pressure ranging between zero gage (no
control flow) and the same pressures as supplied to the oscillator
fluid power input. Additionally, inertance adjustments of the fluid
inertance conduit of the oscillator have shown practical continuous
control over oscillation frequency during operation over several
octaves.
It is still another object of the present invention to provide
arrays of two or more similar fluidic oscillators capable of being
accurately synchronized with each other in any desired phase
relationship by means of appropriate simple fluid conduit
interconnections between such oscillators.
It is further an object of the present invention to provide fluidic
oscillators for use in shower heads to provide dispersal of water
flow into suitable spray and/or massaging and improved cleansing
effects due to the cyclically repetitive flow impact forces on body
surfaces, to further provide shower heads including fluidic
oscillators for the aforementioned purposes, wherein oscillation
frequency and spray angle are adjustable over broad ranges, and
wherein the oscillators, if more than one are used, are
synchronized with each other, and wherein manual controls are
provided for such adjustments, and wherein the shower head has
manually settable valving means for the mode selection of
conventional steady spray or oscillator generated spray and
massaging effects or any combination thereof.
SUMMARY OF THE INVENTION
The invention concerns a fluidic oscillator for use in dispersal of
liquids, in mixing of gases, and in the application of cyclically
repetitive momentum of pressure forces to various materials,
structures of materials, and to living body tissue surfaces for
therapeutic massaging and cleansing purposes.
The fluidic oscillator consists of a chamber, fluid inertance
conduit interconnecting two locations within the chamber, and a
dynamic compliance downstream of these locations. A fluid jet is
issued into the chamber from which the fluid exits through one or
more small openings in form of one or more output streams, the exit
direction of which changes angularly cyclically repetitively from
side to side in accordance with the oscillation imposed within the
chamber on the flow by the dynamic action of the flow itself.
The fluid inertance conduit interconnects two chamber locations on
each side of the issuing jet, and acts as a fluid transfer medium
between these locations for fluid derived from the jet. The exit
region of the chamber is shaped to facilitate formation of a
vortex, which constitutes the dynamic compliance, such that the
jet, in passing through the chamber, tends to promote and feed this
vortex in a supportive manner in absence of any effect from the
inertance conduit and, after the conduit's fluid inertance responds
to the chamber contained flow pattern influences, the jet will tend
to oppose this vortex, will slow it down, and reverse its direction
of rotation. The chamber-contained flow pattern, at one particular
instant in time, consists of the jet issuing into the chamber,
expanding somewhat, and forming a vortex in its exit region. In
view of the continuous outflow of fluid from the periphery of the
vortex through the small exit opening, the vortex would like to
aspirate flow near the chamber wall on the side where the jet feeds
into the vortex and it would like to surrender flow near the
opposite chamber wall. Until the mass of the fluid contained in the
inertance conduit, which interconnects the two sides of the
chamber, is accelerated by these effects of the vortex on the
chamber flow pattern, flow can be neither aspirated on one side nor
surrendered on the other side, and the flow pattern sustains itself
in this quasi-steady state. As soon as the fluid in the inertance
conduit is accelerated sufficiently to feed the aspiration region
and deplete the surrendering region, the flow pattern will cease to
feed the vortex in the chamber exit region and the vortex will
dissipate. Even though now the cause for the acceleration of the
mass of fluid in the inertance conduit has ceased to exist, this
mass of fluid continues to move due to its inertance and it is only
gradually decelerating as its energy is consumed in first
dissipating and them reversing the previous flow pattern state in
the chamber to its symmetrically opposite state, at which time the
mass of fluid in the inertance conduit will be accelerated in the
opposite direction; after which the events continue cyclically and
repetitively in the described manner. An outlet opening from the
exit region of the chamber issues a fluid stream in a sweeping
pattern determined, at the outlet opening, by the vectorial sum of
a first vector, tangential to the exit region vortex and a function
of the spin velocity, and a second vector, directed radially from
the vortex and established by the static pressure in the chamber
together with the dynamic pressure component directed radially from
the vortex. By changing the average static pressure and the vortex
spin velocity and their respective relationship by suitable design
measures, the angle subtended by the sweeping spray can be
controlled over a large range. By suitably configuring the
oscillator, concentrations and distribution of fluid in the spray
pattern can be readily controlled. By changing the inertance of the
fluid inertance conduit, the oscillation frequency can be varied.
By externally imposed pressurization of the chamber exit region,
the oscillation frequency and the sweep angle can be readily
controlled. Two or more oscillators can be synchronized together in
any desired phase relationship by means of appropriate simple
interconnections.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and still further objects, features, and advantages of
the present invention will become apparent upon consideration of
the following detailed description of one specific embodiment
thereof, especially when taken in conjunction with the accompanying
drawings, wherein:
FIG. 1 is an isometric representation of a fluidic oscillator
constructed in accordance with the present invention as could be
seen if, for example, the device were constructed from a
transparent material;
FIG. 2 is a top view in plan of the bottom plate of another fluidic
oscillator according to the present invention;
FIG. 3 is a top view in plan of the bottom plate of another fluidic
oscillator according to the present invention;
FIG. 4 is a top view in plan of the bottom plate of another fluidic
oscillator of the present invention, illustrating diagrammatically
the output waveform associated therewith;
FIGS. 5, 6, 7, 8 and 9 are diagrammatic illustrations showing
successive states of flow within a typical fluidic oscillator of
the present invention;
FIG. 10 is a top view inplan of the silhouette of a fluidic
oscillator of the present invention with a diagrammatic
representation of the waveforms of the output sprays issued from a
typical plural-outlet exit region of a fluidic oscillator according
to the present invention;
FIG. 11 is a top view in plan of the silhouette of a fluidic
oscillator of the present invention, showing diagrammatically means
for adjustment of length of the inertance conduit interconnection
and indicating external connections for additional performance
adjustments and control in accordance with the present
invention;
FIGS. 12 and 13 are diagrammatic top and side view sections,
respectively, of adjustment means for varying the inertance for use
as the fluid inertance conduit of, for example, the oscillators of
FIGS. 1, 10, 11, or 14 in accordance with the present
invention;
FIG. 14 is a diagrammatic representation of the top views in plan
of a multiple fluidic oscillator array synchronized by
interconnecting conduit means in accordance with the present
invention;
FIG. 15 is a perspective external view of a typical shower head,
equipped with performance adjustment means and mode selection
valving and containing two synchronized fluidic oscillators in
accordance with the present invention showing diagrammatically the
output waveforms associated therewith;
FIG. 16 is a diagrammatic front view representation of a shower or
spray booth or shower or spray tunnel multiple spray head and
supply plumbing installation, utilizing as spray heads or nozzles
the fluidic oscillator of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Specifically with reference to FIG. 1 of the accompanying drawings,
an oscillator 14 is shown as a number of channels and cavities,
etc., defined as recesses in upper plate 1, the recesses therein
being sealed by cover plate 2, and a tubing or inertance conduit
interconnection 4 between two bores 5 and 6 extending from the
cavities through the upper plate 1. It is to be understood that the
channels and cavities formed as recesses in plate 1 need not
necessarily be two dimensional but may be of different depths at
different locations, with stepped or gradual changes of depth from
one location to another. For ease in reference, however, entirely
planar elements are shown herein. It is also to be understood that,
whereas a two-plate (i.e. plates 1 and 2) structure is implied in
each of the embodiments, this is intended only to show one possible
means of construction for the oscillator of the present invention.
The invention itself resides in the various passages channels,
cavities, conduits, etc., regardless of the type of structure in
which they are formed. The oscillator 14, as formed by recesses in
plate 1 and sealed by plate 2, includes an upstream chamber region
3 which is generally of an approximately `U`-shaped outline, having
an inlet opening 15 approximately in the center of the base of the
`U`, which inlet opening 15 is the termination of inlet channel 9
directed into the upstream chamber region 3. The open `U`-shaped
upstream chamber region 3 reaches out to join the chamber exit
region 11 which is generally again `U`-shaped, whereby the
transition between the two chamber regions 3 and 11 is generally
somewhat necked down in width near chamber wall transition sections
12 and 13, such that the combination in this embodiment may give
the appearance of what one might loosely call an hour-glass shape.
An outlet opening 10 from the base of the U-shaped chamber exit
region 11 leads to the environment external to the structure
housing the oscillator. Short channels 16a and 16b lead in a
generally upstream direction from the upstream chamber region 3 on
either side of inlet opening 15 (from approximate corner region 8
and 7) to bores 6 and 5, respectively.
Operation of oscillator 14 is best illustrated in FIGS. 5 through
9. For purposes of the description herein, it is assumed that the
working fluid is a liquid and that the liquid is being issued into
an air environment; however, it is to be noted that the oscillator
of the present invention operates as well with gaseous working
fluids, and that any working fluid can be issued into the same or
any other fluid environment. Upon receiving pressurized fluid
through inlet opening 15, a fluid jet is issued and flows through
upstream chamber region 3 and chamber exit region 11 and egresses
through output opening 10, as shown in FIG. 5. However, as a
consequence of the expansion of the fluid jet during its transition
through chamber regions 3 and 11 and a certain loss of cohesiveness
of the jet due to shear effects some portions of its flow are
peeled off before egressing through opening 10, and such portions
of flow quickly fill voids in the chamber cavities as well as
filling the inertance conduit interconnection 4, as further
indicated in FIG. 5. Asymmetries inherent in any structure and
asymmetries inherent in the portions of peeled-off flow on either
side of the jet ensure that complete filling occurs, for all
practical purposes, almost instantaneously. The same aforementioned
inherent asymmetries will cause more flow to be peeled back on one
side of the jet than on the other side, which will necessarily
cause the jet to veer into a vortex flow pattern tending toward the
pattern indicated in the chamber exit region 11 of FIG. 6 (or its
symmetrically opposite pattern). The tendency of the jet to veer
off into the vortex pattern in FIG. 6 is supported and reinforced
by the increasingly larger amount of peeled off flow due to the
more angled approach of the jet to outlet opening 10. Opposed to
this tendency is the jet flow momentum which acts toward a
straightening of the jet. A mutually balance of these influences on
the jet is necessarily reached before the jet can deflect
completely toward the respective side of the chamber exit region
11. By the inherent nature of this flow pattern, a powerful
aspiration region established itself in the approximate area where
the jet flow enters the vortex near the transition between the
chamber regions 3 and 11 on the opposite side of the jet to the
center of the vortex, and the vortex would like to surrender flow
on its side of the jet. The only path which can permit an exchange
of flow between this aspirating region and the surrendering region
is along both sides of the jet in an upstream direction through the
sides of upstream chamber region 3 and via inertance conduit
interconnection 4. However, as the inertance conduit
interconnection 4 represents a significant inertance and thus an
impedance to flow changes by virtue of its physical design, the
mass of fluid contained within this conduit interconnection 4 and
within the remainder of this path between the aspirating and
surrending regions has to be accelerated before a flow between
these two regions may influence and change the described
quasi-steady state flow pattern shown in FIG. 6. As soon as the
flow in inertance conduit connection 4 is accelerated sufficiently
to feed the aspiration region and deplete the surrendering region,
the previously established flow pattern will gradually cease to
feed the vortex in chamber exit region 11 and the vortex will
dissipate, as indicated in FIG. 7. Even though now the cause for
the acceleration of the mass of fluid within inertance conduit
interconnection 4 has ceased to exist, this mass of fluid continues
to move due to its inertance and it will only gradually decelerate
as its dynamic energy is consumed in first dissipating and later
gradually reversing the previous flow pattern state in the chamber
to its symmetrically opposite state, as indicated in FIGS. 8 and 9,
after which this mass of fluid in the inertance conduit connection
will begin to be accelerated in the opposite direction; thereafter,
the sequence of events continues cyclically and repetitively in the
described manner. The sequence of events depicted in FIGS. 6, 8, 8
and 9 (in this order), and as described above, represents flow
pattern states and their changes at various timers within one half
of an oscillation-cycle. In order to visualize the events of the
second half cycle of the oscillation, one need only symmetrically
reverse all depicted flow patterns, starting with the one shown in
FIG. 6 and continuing through FIGS. 7, 8 and 9.
It should perhaps be mentioned here that, whereas the inertance
effect of inertance conduit 4 is clearly analogous to an electrical
inductance L, the effect of a reversing vortex spin within a
confined flow pattern, as occuring within the oscillator of the
present invention, may be considered to represent a dynamic
compliance (even when operating with incompressible fluids), and it
provides an analogous effect not unlike the one of an electrical
capacitance C. From the preceding descriptions, one can readily
visualize the alternating energy exchange between the inertance of
the fluid in the inertance conduit interconnection and the dynamic
compliance of the vortex flow pattern to be somewhat analogous to
the mechanism of a resonant electrical inductance/capacitance (LC)
oscillator circuit.
As a consequence of the aforementioned alternating vortical flow
pattern in chamber exit region 11, flow egresses through output
opening 10 in a side-to-side sweeping pattern disconnects at the
output opening, by the vectorial sum of a first vector, tangential
to the exit region vortex and a function of the spun velocity, and
a second vector, directed radially from the vortex and established
by the static pressure in chamber exit region 11 together with the
dynamic pressure component directed radially from the vortex at
output opening 10. A resulting typical output flow pattern 16 is
shown diagrammatically in FIG. 4. It can be seen in FIG. 4, that
this output flow pattern 16 takes on a sinusoidal shape, wherein
the wave amplitude increases with downstream distance. Since the
shown pattern 16 represents the state in one instant of time, one
must visualize the actual dynamic situation; the wave of pattern 16
travels away from the output opening 10 as it expands in amplitude
subtending angle .alpha..
Referring to FIG. 2, the shown oscillator 17 is represented with
only the plate 18 within which the recesses forming the
oscillator's channels and cavities are contained, the cover plate
being removed for purposes of simplification and clarity of
description. In fact, for most of the oscillators shown and
described hereinbelow, the cover plate has been removed for these
purposes. Oscillator 17 includes an inlet opening 19 similar to
inlet opening 15 of FIG. 1 and an inertance conduit 20 similar to
inertance conduit interconnection 4 of FIG. 1, except that the
latter is in form of a tubing interconnection external to the
oscillator upper plate 1 of FIG. 1 and the former is in form of a
channel interconnection shaped within plate 18 of FIG. 2 itself.
Inlet passage and hole 21 corresponds to inlet channel 9 of FIG. 1.
An upstream chamber region 22 and a chamber exit region 23
correspond to upstream chamber region 3 and chamber exit region 11
in FIG. 1, respectively, except that the chamber wall transition
sections 23 and 24, corresponding to sections 12 and 13 of FIG. 1,
are inwardly curved in a downstream direction until they meet with
sharply inwardly pointed wall sections 25 and 26 which lead to
output opening 10 (same as output opening 10 in FIG. 1). Chamber
exit region 23, even though of slightly different shape to the
corresponding region 11 of FIG. 1, serves the same purpose as
described before. Whereas the necked down transition between
regions 3 and 11 of FIG. 1 provides certain performance features
under certain specific operating conditions, the inwardly curved
wall transition of wall sections 23 and 24 of FIG. 2 provide other
performance features under different operating conditions without
changes in fundamental function of the oscillator, already
described in relation to FIG. 1. For example, the chamber regions
22 and 23 cause the output spray pattern to provide smaller
droplets (among other features) than the hourglass shape of the
corresponding regions of FIG. 1. Inertance conduit 20, being within
plate 18, does not affect the oscillation differently to inertance
conduit 4 of FIG. 1, except insofar as a different inertance
results due to different physical dimensions. Fundamentally, the
inertance is a function of the contained fluid density and it is
proportional to length of the conduit and inversely proportional to
its cross-sectional area. Consequently, longer conduits and/or
conduits with smaller cross-sectional areas provide larger
inertances and thus cause lower oscillation frequencies of the
oscillator.
Referring to FIG. 3, an oscillator 27 is again represented with
only the plate 28 within which the recesses forming the
oscillator's channels and cavities are contained, depicted as such
for the same reason as already described in relation to FIG. 2. The
oscillator 27 of FIG. 3 has the same general configuration shape as
shown for oscillator 17 of FIG. 2, except that the inertance
conduit 29 takes a circular path and chamber regions 30 and 31
define a more smoothed out wall outline even more inwardly curved
and already beginning its curvature approximate to both ends of
inertance conduit 29. As discussed in relation to FIG. 2, different
layouts of inertance conduits have no bearing on the fundamental
oscillator operation, yet the flexibility of layout provides
distinct advantages in design and construction of actual products
comprising the oscillator of the present invention, and it is a
particular purpose of FIGS. 1, 2, 3, and 4 to show such
flexibility. Oscillator 27 of FIG. 3, in view of its discussed more
inwardly curved smoothed out chamber wall outline, in comparison
with oscillator 17 of FIG. 2, provides certain different
performance characteristics, for example narrower spray output
angles, move cohesive output flow with larger droplets in a
narrower range of size distribution, etc. The fundamental function
and operation of oscillator 27 is the same as already described in
relation with the oscillator 14 of FIG. 1.
Referring specifically to FIG. 4, an oscillator 32 is represented
with only the plate 33 within which the recesses forming the
oscillator's channels and cavities are contained, depicted as such
for the same reason as already described in relation to FIG. 2.
Oscillator 32 has the same general configuration and shape as shown
for oscillator 14 of FIG. 1, except that the inertance conduit 34
is shaped similarly to inertance conduit 29 of FIG. 3 and that it
is also contained as a recess within plate 33, corresponding to the
construction shown in FIG. 3, and that inertance conduit 34 is laid
out in a very short path, the effect of which is an increase in
oscillation frequency for reasons already discussed in relation to
FIG. 2. Chamber region 34 is simply adapted in its width near inlet
opening 19 to mate its walls with the outer walls of the ends of
inertance conduit 34, which has no bearing on the general function
and operation of the oscillator 32 as distinct from oscillator 14,
17, and 27 (FIGS. 1, 2, and 3, respectively). Chamber exit region
36 corresponds to chamber exit region 11 of FIG. 1 in configuration
and function. In comparison with, for example, the configuration of
oscillator 27 of FIG. 3, the chamber shape, particularly the wider
and generally larger exit region 36 of FIG. 4, will cause different
performance characteristics; for example, wider spray output angles
.alpha., still more cohesive output flow with narrower size
distributions of droplets, smoother output waveforms of more
sinusoidal character, etc. A typical output waveform applicable in
general to all the oscillators of the present invention is
diagrammatically shown as the output flow pattern 16 of FIG. 4. The
fundamental function and operation of oscillator 32 of FIG. 4 is
the same as already described in relation with oscillator 14 of
FIG. 1.
It is to be noted, with respect to the effects of relatively gross
changes of inertances of the inertance conduits in relation to
particularly the width and length dimensions of chamber exit
regions, that definite performance tendencies have been
experimentally verified, as indicated in the following: Very high
relative inertances cause output waveforms to take on more and more
trapezoidal characteristics. Gradually reduced relative inertances
cause output waveforms to approach and eventually attain a
sinusoidal character. And further relative reductions in inertance
cause sharpening of wavepeaks whereby waveforms eventually attain
triangular shapes. Additional relative inertance reductions result
in little, if any, additional wave shape changes but they cause
gradual sweep or spray angle reductions (which up to this point
remain virtually constant with inertance changers). Naturally,
oscillation frequencies changed during these experiments in
accordance with the different relationship between applicable
characteristic oscillator parameters and employed inertances.
Design control over output waveforms is an important aspect of the
present invention since the output waveform largely establishes the
spray flow distribution or droplet density distribution across the
output spray angle and different requirements apply to different
products and uses. For example, trapezoidal waveforms generally
provide higher densities at extremes of the sweep angle than
elsewhere. Sinusoidal waveforms still provide somewhat uneven
distributions with higher densities at extremes of the sweep angle
and usually lower densities near the center. Triangular waveforms
generally offer even distribution across the sweep angle.
Referring to FIG. 10, an oscillator of the general type illustrated
in FIG. 1 is modified by replacing output opening 10 of FIG. 1 with
three output openings 37, 38, and 39 located in the same general
area. In fact, any number of output openings may be provided along
the frontal (output) periphery of chamber exit regions at any
desired spacings and of same or different sizes. Output openings
37, 38, and 39 in FIG. 10 will each issue an output flow pattern
which will exhibit the same characteristics as described in detail
in relation to FIGS. 1 or 4. The sweep angles of the multiple
output flow patterns may be separated or they may overlap, as
required by performance needs. Waveforms will be of generally
identical phase relationship (and frequency). Inertance conduit
interconnection 40 is shown to interconnect areas 41 and 42
directly without employment of intermediate channels such as ones
shown in FIG. 1 as short channels 16 and 17. This variation is
shown purely to indicate another design option possible when size
and other construction criteria allow or impose such differences,
and it does not affect the fundamental function and operation of
the oscillator shown in FIG. 10, which is the same as already
described in relation with the oscillator 14 of FIG. 1. The purpose
for multiple output openings in oscillators, as illustrated in FIG.
10, is to be able to obtain different output spray characteristics;
for example, different distributions, spray angles, smaller droplet
sizes, low spray impact forces, several widely separated spray
output patterns, etc.
Referring to FIG. 11, an oscillator of the general type illustrated
in FIG. 1 is modified by provision of an opening 43 into the
chamber exit region 44, by employment of an inlet opening and an
inlet hole 47 like inlet opening 19 and inlet passage and an inlet
hole 47 like inlet opening 19 and inlet passage and hole 21, both
in FIG. 2, and by utilization of an adjustable length inertance
conduit interconnection 45. FIG. 11 shows further fluid supply
connections to the inlet hole 47 as well as to opening 43, both
leading from valving means 46, represented in block form. The
oscillator of the arrangement in FIG. 11, operating in the same way
as oscillator 14 of FIG. 1, upon receiving pressurized fluid
through opening 47, is not affected by the presence of opening 43
as long as the feed to opening 43 is closed off, and it is not
affected by the presence of the adjustable length inertance conduit
interconnection 45, except to the extent that the oscillation
frequency will change as a function of a change in length of
interconnection 45. The oscillation frequency may be further
changed by adjustment of valving means 46 in admitting pressurized
fluid through opening 43 into region 44. Such admittance of fluid
is of relatively low flow velocities and generally does not affect
the fundamental flow pattern events in region 44. However, as
pressure is increased to opening 43, predominantly the static
pressure increases in region 44, and also in the remainder of the
oscillator. This has two main effects: For one, the supply flow
through opening 47 will be reduced due to the backpressure increase
experienced, and consequently the oscillation frequency will be
reduced, as the jet velocity reduces also; and secondly, the static
pressure increased particularly in region 44. A change in the
vectorial sum, at the oscillator output opening, of the various
velocities, described in detail in relation to the operation of the
oscillator embodiment shown in FIG. 1, such that the second vector
which is directed radially from the vortex increases in relation to
the first vector which is tangential to the exit region vortex, and
consequently the output flow sweep angle decreases. Thus one can
see that an adjustment of pressure supplied to opening 43 changes
oscillation frequency and output flow sweep angle. At the same
time, only minimal total flow rate changes for the oscillator are
experienced, because pressurization of region 44 via opening 43 and
the inflow of additional fluid caused thereby through opening 43 is
to some extent compensated by the concomitant decrease in supply
flow through inlet hole 47. Pressure adjustment by way of valving
means 46 may be applied exclusively to opening 43, whilst holding
pressure to inlet hole 47 constant, or both pressure supplies may
be independently adjusted, or both pressures may be adjusted by
valving arrangements ganged together in any desired relationship.
Furthermore, the pressure (and flow) input into opening 43 may be
fed from any suitable source of fluid, for example one which will
provide a time or event dependent variation in pressure such as to
control or modulate the oscillator onput as a function thereof.
Experimental results have shown practical a frequency adjustment
range of over one octave and an output sweep angle adjustment range
from almost zero degrees to over ninety degrees without exceeding
the supply pressure to inlet hole 47 by the adjustment pressure to
opening 43. In addition to the performance adjustments afforded by
the aforementioned means, oscillation frequency si independently
adjustable by means of length adjustment of the adjustable length
inertance conduit interconnection 45, which is simply an
arrangement similar to the slide of a trombone, whereby the length
of the conduit may be continuously varied. Experiments have shown
practical adjustment ranges up to several octaves employing such an
arrangement. It is feasible to provide valving arrangements ganged
to adjust not only the pressures to opening 43 and to inlet hole 47
but also mechanically coupled to adjust the length of inertance
conduit interconnections 45 with a single control means, such that,
for example, a single manually rotatable knob causes an oscillator
output performance change over a further extended very wide range.
The aforementioned performance adjustment capabilities are
particularly useful in processes where in-operation requirements
vary. In other applications, adjustability is needed to adapt
performance to subjective requirements; for example, oscillators
employed in massaging shower heads for therapentic or simple
recreational purposes would exhibit particularly advantageous
appeal if their effects more capable to be adjusted in a wide range
of individual subjective needs and desires.
Referring to FIGS. 12 and 13, a compact adjustment means for
varying the inertance of the inertance conduit interconnection of
any of the oscillators shown in FIGS. 1 through 11 and 14 is
illustrated. A cylindrical piston 47a is axially movably arranged
within a cylindrically hollow body 48, wherein piston 47a is
peripherally sealed by seal 49. A portion of the body 48 is of a
somewhat larger internal diameter than piston 47a, such that an
annular cylindrical void 48a is formed between piston 47a and body
48 when piston 47a is fully moved into body 48, and such that, in a
partially moved-in position of piston 47a, a partially annular and
partially cylindrical void is formed, and such that a cylindrical
void is formed when piston 47a is withdrawn further. The internal
peripheral wall of the cylindrical hollow body 48 as two conduit
connections in proximity to each other and oriented approximately
tangentially to the internal cylindrical periphery, wherein the
conduit entries point away from each other. The conduits lead to
interconnection terminals 50 and 51, respectively. Since the
inertance between the two terminals 50 and 51 is a proportional
function of the length and an inversely proportional function of
the cross-sectional area of the path a fluid flow would be forced
to take when passing between terminals 50 and 51 through the means
shown in FIGS. 12 and 13, it can be shown that the inertance of
this path is continuously varied as piston 47a is moved in body 48
and as the internal void changes shape and volume between one
extreme of a cylindrical annulus, when highest inertance is
obtained, and the other extreme of a cylinder, when lowest
inertance is reached. In comparison with the variable inertance
conduit interconnection 45 of FIG. 11, the arrangement of FIGS. 12
and 13 offers compactness, simpler sealing, and a less critical
construction. Replacing the slide of interconnection 45 of FIG. 11
with the arrangement of FIGS. 12 and 13 by connecting terminals 50
and 51 respectively to the two conduit stubs opened up by the
removal of interconnection 45, all operation and adjustment
described in relation to FIG. 11 applies.
Referring to FIG. 14, two oscillators of the general type
illustrated in FIG. 1 are interconnected by suitable synchronizing
conduits 52 and 53 between symmetrically positioned locations of
the respective inertance conduit interconnections, particularly
between such locations in proximity to the chamber entries 54, 55,
56, and 57 of the inertance conduit interconnections. Conduit 52
connects entry 54 with entry 57 and conduit 53 connects entry 55
with entry 56. The two oscillators in the shown connection will
oscillate in synchronism, provided they are both of a like design
to operate at approximately the same frequencies if supplied with
the same pressure, and their relative phase relationship will be
180 degrees apart when viewed as drawn. Interchanging the
connections of two entries only at one oscillator, for example
re-connecting conduit 52 to entry 55 and conduit 53 to entry 54
will provide an in-phase relationship. Different lengths and
unequal lengths of conduits 52 and 53, as well as changes of the
connecting locations of synchronizing conduits along the inertance
conduit interconnections result in a variety of different phase
relationships. It is also feasible to thusly interconnect unlike
oscillators to provide shaving at harmonic frequencies. More than
two oscillators may be interconnected and synchronized in like
manner and such arrays may be interconnected to provide different
phase relationships between different oscillators. Furthermore,
series interconnections between plural oscillators may be employed,
wherein synchronizing conduits can be employed to provide the
inertance previously supplied by the inertance conduit
interconnections and wherein individual oscillator's inertance
conduit interconnections may be omitted.
Referring to FIG. 15, a typical hand-held massaging shower head is
illustrated to contain two synchronized oscillators of the general
type shown in FIG. 1, interconnected by an arrangement as indicated
in FIG. 14, and equipped with variable performance adjustment
arrangements generally described in relation to FIG. 11 and FIGS.
12 and 13. The shower head is supplied with water under pressure
through hose 58 and it commonly contains valving means for the mode
selection between conventional steady spray and massaging action.
Manual controls 59 and 60 are arranged such as to advantageously
provide not only mode selection control but also the adjustment
control for frequency and sweep angle (as described in relation to
FIG. 11, by means of the pressure adjustment to opening 43 and/or
by ganged or combined pressure adjustment to supply hole 47), all
the preceding adjustment controls and the mode selection being
preferably arranged in one of the two manual controls 59 or 60, and
to provide the independent frequency adjustment (as described in
relation to FIGS. 11, 12 and 13, by means of the inertance
adjustment of inertance conduit interconnection 45 or by means of
the arrangement shown in FIGS. 12 and 13) in the other of the two
manual controls 59 or 60. The gauged or combined mode selection and
frequency and sweep angle control may be a valving arrangement
which allows supply water passage only to the conventional steady
spray nozzles when the manual control is in an extreme position.
When the manual control is rotated by a certain angle, the valving
arrangement permits supply water passage also to the supply inputs
of the oscillators and on further control rotation, water passage
is allowed only to the supply inlets of the oscillators. Yet
additional rotation of the manual control will reduce the frequency
and sweep angle by adjustment of the respective pressures to the
oscillators. The independent frequency adjustment is a mechanical
arrangement facilitating the translational motion needed to the
respective inertance conduit interconnection adjustment described
earlier in detail. Thus for example, the respective manual control
59 or 60 may be adjusted by rotation between two extreme position
whilst the oscillation frequency changes between corresponding
values. It should be noted here that the frequency adjustments bear
such a relationship with respect to each other that the frequency
range ratio of one is approximately multiplied by the frequency
range ratio of the other to obtain the total combined frequency
range, which is, therefore, greatly expanded due to the two control
adjustments.
In FIG. 16 there is illustrated an application of the oscillator of
the present invention in a shower or spray booth (or shower or
spray tunnel), wherein a plurality of oscillators in form of
identical nozzles 61 is arranged and mounted in various locations
along a liquid supply conduit 62 which feeds liquid under pressure
to each nozzle 61. Conduit 62 is shaped along its length into a
door-outline or any appropriate form for the particular
application. Nozzles 61 are oriented inwardly such as to provide
overlapping spray patterns. Nozzles 61 are preferably oriented with
the plane of their spray patterns in the plane defined by the shape
of supply conduit 62. It is the purpose of such an arrangement to
provide large spray area coverage with minimal flow consumption,
for example in shower booths or in spray booths, wherein one or
more such arrangements may be installed. The oscillator nozzles of
the present invention not only are capable of providing the large
area coverage with relatively fine spray at minimal flow
consumption, but they provide additional advantages, in
arrangements as shown in FIG. 16, of being much less liable to
clogging in comparison with conventionally utilized steady stream
or spray nozzles due to the latter's small flow openings in
relation to the much larger oscillator channels. Furthermore, for
equal effect, orders of magnitude larger numbers of conventional
nozzles are needed than the few side angle spray nozzles required
to provide the same coverage.
While I have described and illustrated various specific embodiments
of my invention, it will be clear that variations from the details
of construction which are specifically illustrated and described
may be resorted to without departing from the true spirit and scope
of the invention as defined in the appended claims.
* * * * *