U.S. patent application number 14/807667 was filed with the patent office on 2016-07-07 for solid grain structures, systems, and methods of forming the same.
This patent application is currently assigned to Utah State University. The applicant listed for this patent is Spencer Mathias, Daniel P. Merkley, Mansour Sobbi, Sean D. Walker, Stephen A. Whitmore. Invention is credited to Spencer Mathias, Daniel P. Merkley, Mansour Sobbi, Sean D. Walker, Stephen A. Whitmore.
Application Number | 20160194256 14/807667 |
Document ID | / |
Family ID | 56286127 |
Filed Date | 2016-07-07 |
United States Patent
Application |
20160194256 |
Kind Code |
A1 |
Whitmore; Stephen A. ; et
al. |
July 7, 2016 |
SOLID GRAIN STRUCTURES, SYSTEMS, AND METHODS OF FORMING THE
SAME
Abstract
Devices, methods, and systems for providing a solid grain fuel
for a hybrid rocket. In one embodiment, the solid grain fuel
includes a housing having a length extending between a first side
and a second side. The housing defines a central axis and a bore
extending from the first side to the second side. The bore of the
housing extends with a helical configuration along the length of
the housing. Further, the housing includes multiple segments
configured to interlock together to form the bore along the length
of the housing.
Inventors: |
Whitmore; Stephen A.;
(Logan, UT) ; Merkley; Daniel P.; (Layton, UT)
; Sobbi; Mansour; (Twin Falls, ID) ; Walker; Sean
D.; (Logan, UT) ; Mathias; Spencer; (North
Logan, UT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Whitmore; Stephen A.
Merkley; Daniel P.
Sobbi; Mansour
Walker; Sean D.
Mathias; Spencer |
Logan
Layton
Twin Falls
Logan
North Logan |
UT
UT
ID
UT
UT |
US
US
US
US
US |
|
|
Assignee: |
Utah State University
North Logan
UT
|
Family ID: |
56286127 |
Appl. No.: |
14/807667 |
Filed: |
July 23, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13953877 |
Jul 30, 2013 |
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14807667 |
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62029368 |
Jul 25, 2014 |
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61677254 |
Jul 30, 2012 |
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61677266 |
Jul 30, 2012 |
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61677418 |
Jul 30, 2012 |
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61677426 |
Jul 30, 2012 |
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61677298 |
Jul 30, 2012 |
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Current U.S.
Class: |
149/2 ;
149/109.6 |
Current CPC
Class: |
C06B 45/00 20130101;
C06B 21/0033 20130101; F05D 2250/25 20130101; F02K 9/72
20130101 |
International
Class: |
C06B 21/00 20060101
C06B021/00; C06B 45/00 20060101 C06B045/00 |
Goverment Interests
GOVERNMENT SPONSORED RESEARCH
[0003] This invention was made with government support under
contracts NNX09AW08A and NNX12AN12G awarded by NASA. The government
has certain rights in the invention.
Claims
1. A solid grain fuel for a hybrid rocket, comprising: a housing
having a length extending between a first side and a second side,
the housing defining a central axis and a bore extending from the
first side to the second side, the bore extending with a helical
configuration along the length of the housing, the housing
including multiple segments configured to interlock together to
form the bore along the length of the housing.
2. The solid grain fuel of claim 1, wherein: each of the multiple
segments comprises multiple flat layers and each flat layer defines
a plane that is transverse relative to the central axis of the
housing, and the bore extends through each of the multiple flat
layers
3. The solid grain fuel of claim 1, wherein the housing is formed
of acrylonitrile butadiene styrene (ABS).
4. The solid grain fuel of claim 1, wherein the bore comprises a
circular cross-section.
5. The solid grain fuel of claim 1, wherein the multiple segments
include opposite ends, at least one of the opposite ends including
an orientation feature configured to couple to an end of another
one of the multiple segments so that the bore in each of the
multiple segments collectively defines the helical configuration
within the coupled multiple segments.
6. A solid grain fuel for a hybrid rocket, comprising: a housing
having a length extending between a first side and a second side,
the housing defining a central axis and a bore extending from the
first side to the second side, the bore extending with a helical
configuration along the length of the housing, the housing
including acrylonitrile butadiene styrene (ABS).
7. The solid grain fuel of claim 6, wherein the housing comprises
multiple segments configured to interlock together to form the bore
along the length of the housing.
8. The solid grain fuel of claim 7, wherein the multiple segments
include opposite ends, at least one of the opposite ends including
an orientation feature configured to couple to an end of another
one of the multiple segments so that the bore in each of the
multiple segments collectively defines the helical configuration
within the coupled multiple segments.
9. The solid grain fuel of claim 7, wherein each of the multiple
segments comprises multiple flat layers.
10. The solid grain fuel of claim 7, wherein the bore comprises a
circular cross-section.
11. A method of forming a solid grain fuel for a hybrid rocket, the
method comprising: forming multiple solid grain segments with
additive layering with acrylonitrile butadiene styrene (ABS)
wherein each of the multiple solid grain segments define a bore
extending therethrough; and coupling the multiple solid grain
segments together to form an elongated housing such that the bore
extending through each of the solid grain segments collectively
defines a helically extending bore that extends along a length of
the elongated housing between opposite first and second sides.
12. The method according to claim 11, wherein the forming
comprises: forming each of the multiple solid grain segments with
multiple flat layers with fused deposition modeling.
13. The method according to claim 12, wherein the forming comprises
forming the multiple solid grain segments with acrylonitrile
butadiene styrene (ABS).
14. The method according to claim 11, wherein the forming comprises
forming the multiple solid grain segments with inter-locking
features to inter-lock the multiple solid grain segments together
to form the elongated housing.
15. The method according to claim 11, wherein: the forming
comprises forming the multiple solid grain segments with a keying
feature on at least one of the oppositely facing sides of the
multiple solid grain segments, and the coupling comprises orienting
each one of the multiple solid grain segments relative to another
one of the multiple solid grain segments with the keying feature to
form the helically extending bore of the elongated housing.
16. A hybrid rocket system, comprising: a container sized to
contain liquid or gaseous fuel; a solid grain portion having a
length extending between a first side and a second side, the first
side configured to receive fuel from the container, wherein: the
sold grain portion defines a central axis and a bore extending
between the first side and the second side; the bore extends with a
helical configuration along the length of the solid grain portion;
and the solid grain portion comprises multiple segments configured
to interlock together to form the bore along the length of the
housing; and a nozzle coupled to the second side of the solid grain
portion, the nozzle configured to manipulate thrust to the rocket
system.
17. The hybrid rocket system of claim 16, wherein each of the
multiple segments comprises multiple flat layers and the bore
extends through each of the multiple flat layers.
18. The hybrid rocket system of claim 16, wherein the solid grain
portion is formed of acrylonitrile butadiene styrene (ABS).
19. The hybrid rocket system of claim 16, wherein the bore
comprises a circular cross-section.
20. The hybrid rocket system of claim 16, wherein the multiple
segments include opposite ends, at least one of the opposite ends
including an orientation feature configured to couple to an end of
another one of the multiple segments so that the bore in each of
the multiple segments collectively defines the helical
configuration within the multiple segments.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part application to
U.S. Non-provisional application Ser. No. 13/953,877, filed on Jul.
30, 2013 and entitled "Multiple Use Hybrid Rocket Motor," which is
hereby incorporated by reference in its entirety and which claims
the benefit under 35 U.S.C. .sctn.119(e) of U.S. Provisional
Application Nos. 61/677,254; 61/677,266; 61/677,418; 61/677,426;
and 61/677,298; all filed Jul. 30, 2012, and all of which are
hereby incorporated by reference in their entirety.
[0002] This application also claims priority to U.S. Provisional
Application No. 62/029,368, filed on Jul. 25, 2014, and entitled
"Solid Grain Structures, Systems, and Methods of Forming the Same,"
which is herein incorporated by this reference in its entirety.
TECHNICAL FIELD
[0004] The present invention relates generally to hybrid rocket
systems and, more specifically, to devices, systems and methods of
forming a solid grain structure for a hybrid rocket system.
BACKGROUND
[0005] Hybrid rocket motors, in spite of their well-known safety
and handling advantages, have not seen widespread commercial use
due to internal motor ballistics that produce fuel regression rates
typically 25-30% lower than solid fuel motors in the same thrust
and impulse class. These lowered fuel regression rates tend to
produce unacceptably high oxidizer-to-fuel (O/F) ratios. These high
O/F ratios lead to grain and nozzle erosion and reduced motor duty
cycles. To achieve O/F ratios that produce acceptable combustion
characteristics, traditional cylindrical fuel ports have been
fabricated to have a longer length-to-diameter ratio. This high
aspect ratio results in poor volumetric efficiency and presents the
potential for lateral structural loading issues in the motor during
high thrust burns.
SUMMARY
[0006] Applicants of the present disclosure have identified that it
would be advantageous to provide a hybrid rocket system that
provides acceptable fuel regression rates and O/F ratios similar or
better than solid fuel motors without the deficiencies of poor
volumetric efficiency and lateral structural loading.
[0007] Embodiments of the present invention are directed to various
devices, systems and methods of forming a solid grain fuel for a
hybrid rocket. For example, in one embodiment, the solid grain fuel
includes a housing having a length extending between a first side
and a second side. The housing defines a central axis and a bore
extending from the first side to the second side. The bore of the
housing extends with a helical configuration along the length of
the housing. Further, the housing includes multiple segments
configured to interlock together to form the bore along the length
of the housing.
[0008] In one embodiment, each of the multiple segments includes
multiple flat layers. Such flat layers may be formed by fused
deposition modeling or three dimensional printing, or the like. In
another embodiment, each of the multiple flat layers define a plane
that is transverse relative to the central axis of the housing. In
still another embodiment, the bore extends through each of the
multiple flat layers.
[0009] In another embodiment, the housing is formed of
acrylonitrile butadiene styrene (ABS). In another embodiment, the
bore includes a circular cross-section. In still another
embodiment, the multiple segments include opposite ends, at least
one of the opposite ends including an orientation feature
configured to couple to an end of another one of the multiple
segments so that the bore in each of the multiple segments
collectively defines the helical configuration within the coupled
multiple segments.
[0010] In accordance with another embodiment of the present
invention, a solid grain fuel for a hybrid rocket is provided. In
one embodiment, the solid grain fuel includes a housing having a
length extending between a first side and a second side. Such
housing defines a central axis and a bore extending from the first
side to the second side such that the bore extends with a helical
configuration along the length of the housing. The housing in this
embodiment includes an acrylonitrile butadiene styrene (ABS)
material.
[0011] In another embodiment, the housing includes multiple
segments configured to interlock together to form the bore along
the length of the housing. In another embodiment, the multiple
segments include opposite ends, at least one of the opposite ends
including an orientation feature configured to couple to an end of
another one of the multiple segments so that the bore in each of
the multiple segments collectively defines the helical
configuration within the coupled multiple segments. In another
embodiment, each of the multiple segments includes multiple flat
layers. In yet another embodiment, the bore includes a circular
cross-section.
[0012] In accordance with another embodiment of the present
invention, a solid grain fuel for a hybrid rocket is provided. In
one embodiment, the solid grain fuel includes a modular housing
including multiple segments each configured to be coupled together
to form the modular housing. The modular housing includes a length
extending between a first side and a second side. Such modular
housing defines a helical extending bore extending along the length
and between the first side to the second side of the modular
housing. Further, the modular housing includes an acrylonitrile
butadiene styrene (ABS) material.
[0013] In another embodiment, each of the multiple segments
includes multiple flat layers. In another embodiment, the multiple
segments include opposite ends, at least one of the opposite ends
including an orientation feature configured to couple to an end of
another one of the multiple segments so that a bore in each of the
multiple segments of the modular housing collectively defines the
helically extending bore.
[0014] In accordance with another embodiment of the present
invention, a method of forming a solid grain fuel for a hybrid
rocket is provided. The method includes: forming multiple solid
grain segments such that each of the multiple solid grain segments
define a bore extending therethrough; and coupling the multiple
solid grain segments together to form an elongated housing such
that the bore extending through each of the solid grain segments
collectively defines a helically extending bore that extends along
a length of the elongated housing between opposite first and second
sides.
[0015] In another embodiment, the forming step includes the step of
forming each of the multiple solid grain segments with multiple
flat layers. In another embodiment, the forming step includes the
step of forming the multiple solid grain segments with fused
deposition modeling. In still another embodiment, the forming step
includes the step of forming the multiple solid grain segments with
an acrylonitrile butadiene styrene (ABS) material. In yet another
embodiment, the forming step includes the step of forming the
multiple solid grain segments with additive layering with an
acrylonitrile butadiene styrene (ABS) material.
[0016] In another embodiment, the forming step includes the method
step of forming the multiple solid grain segments with
inter-locking features to inter-lock the multiple solid grain
segments together to form the elongated housing. In another
embodiment, the forming step includes the method step of forming
the multiple solid grain segments with an orientation feature or
keying feature on at least one of the oppositely facing sides of
the multiple solid grain segments. In still another embodiment, the
coupling step includes the step of orienting each one of the
multiple solid grain segments relative to another one of the
multiple solid grain segments with the orientation feature to form
the helically extending bore of the elongated housing.
[0017] In accordance with another embodiment of the present
invention, a hybrid rocket system is provided. In one embodiment,
the hybrid rocket system includes a container, a solid grain
portion, and a nozzle. The container is sized to contain liquid or
gaseous fuel. The solid grain portion includes a length extending
between a first side and a second side such that the first side is
configured to receive fuel from the container. The sold grain
portion defines a central axis and a bore extending between the
first side and the second side such that the bore extends with a
helical configuration along the length of the solid grain portion.
The nozzle is coupled to the second side of the solid grain portion
such that the nozzle is configured to manipulate thrust to the
rocket system.
[0018] In another embodiment, the solid grain portion includes
multiple segments configured to interlock together to form the bore
along the length of the housing. In another embodiment, each of the
multiple segments includes multiple flat layers. In still another
embodiment, the bore extends through each of the multiple flat
layers. In another embodiment, the solid grain portion is formed of
an acrylonitrile butadiene styrene (ABS) material. In another
embodiment, the bore includes a circular cross-section. In yet
another embodiment, the multiple segments include opposite ends, at
least one of the opposite ends including an orientation feature
configured to couple to an end of another one of the multiple
segments so that the bore in each of the multiple segments
collectively defines the helical configuration within the multiple
segments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The foregoing features of embodiments of the present
disclosure will become more fully apparent from the following
description and appended claims, taken in conjunction with the
accompanying drawings. Understanding that these drawings depict
only typical embodiments of the invention and are, therefore, not
to be considered limiting of its scope, the invention will be
described with additional specificity and detail through use of the
accompanying drawings in which:
[0020] FIG. 1 is a plan view of a hybrid rocket;
[0021] FIG. 2A is an elevation view of a solid fuel grain with a
circular cross-sectional helical bore;
[0022] FIG. 2B is a detail view of the solid grain fuel of FIG. 2A
illustrating multiple flat layers;
[0023] FIG. 3A is an elevation view of a solid fuel grain with a
square cross-sectional helical bore;
[0024] FIG. 3B is a detail view of the solid grain fuel of FIG. 3A
illustrating multiple flat layers;
[0025] FIG. 4 illustrates a solid grain fuel and multiple segments
of a solid grain fuel configured to couple together; and
[0026] FIG. 5 is a method of forming a solid grain fuel.
DETAILED DESCRIPTION
[0027] The present disclosure covers various devices, systems and
methods of forming a solid grain fuel for a hybrid rocket. In the
following description, numerous specific details are provided for a
thorough understanding of specific preferred embodiments. However,
those skilled in the art will recognize that embodiments can be
practiced without one or more of the specific details, or with
other methods, components, materials, etc. In some cases,
well-known structures, materials, or operations are not shown or
described in detail in order to avoid obscuring aspects of the
preferred embodiments. Furthermore, the described features,
structures, or characteristics may be combined in any suitable
manner in a variety of alternative embodiments. Thus, the following
more detailed description of the embodiments of the present
invention, as illustrated in some aspects in the drawings, is not
intended to limit the scope of the invention, but is merely
representative of the various embodiments of the invention.
[0028] In this specification and the claims that follow, singular
forms such as "a," "an," and "the" include plural forms unless the
content clearly dictates otherwise. All ranges disclosed herein
include, unless specifically indicated, all endpoints and
intermediate values. In addition, "optional," "optionally," or "or"
refer, for example, to instances in which subsequently described
circumstance may or may not occur, and include instances in which
the circumstance occurs and instances in which the circumstance
does not occur. The terms "one or more" and "at least one" refer,
for example, to instances in which one of the subsequently
described circumstances occurs, and to instances in which more than
one of the subsequently described circumstances occurs.
[0029] FIG. 1 illustrates an example hybrid rocket 100 that
includes a housing 10 having a length extending between a first
side 11 and a second side 12. In this example, the housing or fuel
grain 10 defines a central axis 22 and a bore or helical fuel port
20 extending from the first side 11 to the second side 12 inside
the fuel grain 10. The bore 20 extends with a helical configuration
along the length of the housing 10. The housing 10 also includes
multiple modular housing segments 30a, 30b, and 30c, configured to
interlock together through matching interlocking features 35 to
form the bore 20 along the length of the housing 10. The housing 10
or multiple modular housing segments 30a, 30b, and 30c may be
manufactured by fused deposition modeling (FDM) with acrylonitrile
butadiene styrene (ABS).
[0030] In FIG. 1, the helical fuel port 20 is further defined by a
pitch rotation P, a bore diameter D, and a mean diameter L. These
dimensions may be adjusted to achieve different initial fuel port
areas and different oxidizer-to-fuel (O/F) ratios in operation.
[0031] ABS is a thermoplastic that melts before vaporizing when
subjected to heat. This property makes ABS one of the materials of
choice for fused deposition modeling (FDM) rapid prototyping
machines. Because ABS can be formed into a wide variety of shapes
using modern additive manufacturing and rapid prototyping
techniques, it is possible to embed complex high-surface area flow
paths within the fuel grain. These internal flow paths allow for
motor aspect ratios that are significantly shorter than can be
achieved using conventional solid, hybrid, or mono-propellant
technologies. These flow paths cannot be achieved with
thermo-setting materials that are cast using tooling that must be
removed once the material is set.
[0032] The embedded helical port or bore 20 provides an extended
length flow path and a large surface area contact in a short form
factor. Centrifugal forces created by combustion gases and oxidizer
rotating in and flowing through the helical fuel port or bore 20
significantly increases the fuel regression rates and propellant
mass flow from the fuel grain or housing 10.
[0033] In order to significantly increase the regression rate, a
helical port or bore 20 fuel design feature increases the nominal
surface skin friction while also minimizing the effects of radial
surface blowing. A helical pipe flow with cylindrical ports shows
significantly increased end-to-end pressure losses when compared to
flows through straight pipes with identical cross sections. Thus,
helical flows have the effect of significantly increasing the local
skin friction coefficient. Helical flows also introduce a
centrifugal component into the flow field. In hybrid rocket
applications such as hybrid rocket 100, this centrifugal component
will have the effect of thinning the wall boundary layer--bringing
the flame zone closer to the wall surface and increasing the flame
diffusion efficiency. An increased flame diffusion efficiency
increases O/F ratios. Helical fuel ports in a wide variety of cross
sectional areas can be easily manufactured using ABS fuel materials
manufactured by FDM techniques.
[0034] FIG. 2A illustrates the housing 115 with similar features to
housing 10 illustrated in FIG. 1. Housing 115 includes multiple
modular housing segments 31a, 31b, and 31c, configured to interlock
together to form the bore 20 along the length of the housing 115.
More segments may be used to extend the overall length of the
housing 115. Segments such as 31a, 31b, and 31c may couple or
"snap" together with matching interlocking features and then
further secured using ABS pipe joint cement.
[0035] FIG. 2B is a detail view of multiple flat layers 50 of the
housing 115. In this example, each of the multiple flat layers 50
defines a plane that is transvers relative to the central axis 22
of the housing 115.
[0036] FIGS. 3A and 3B similarly illustrate a housing 210 with a
square bore 24 extending in a helical configuration along the
length of the housing 210.
[0037] FIG. 4 illustrates a modular housing 310 that includes
multiple segments 33a, 33b, and 33c. The segments 33a, 33b, and 33c
are configured to couple together through matching interlocking
features 62 to form the modular housing 310. If made of ABS, the
segments 33a, 33b, and 33c may be further secured together to form
an air-tight connection with ABS pipe joint cement. Although not
shown, a helical bore extends through the segments 33a, 33b, and
33c.
[0038] FIG. 4 further illustrates how the multiple segments 33a,
33b, and 33c have opposite ends that include an orientation feature
63 configured to couple one segment to another segment such that
the bore in each of the multiple segments of the modular housing
collectively defines a helical extending bore.
[0039] FIG. 5 illustrates a method 500 for forming an elongated
housing of a solid grain fuel structure. A method includes a step
510 of forming multiple solid grain segments such that each of the
multiple solid grain segments define a bore extending therethrough
and an additional step 520 of coupling the multiple solid grain
segments together to form an elongated housing.
* * * * *