Patent Application
20200291899
The present invention relates to the field of rocket fuel, and more particularly to a hybrid rocket engine with an improved solid fuel segment.
Rocket fuels are mainly divided into types for solid rocket, liquid rocket and hybrid rocket. The fuel of solid rocket motors is directly installed at the rear of the rocket. When used, an igniter is used to initiate fuel combustion and generate thrust to push the rocket. Because solid rocket fuel does not require additional fuel tanks or pipelines for delivery or pressurization, solid rocket motors are much simpler than liquid rocket engines.
Liquid rockets employ rocket engines that use propellant mixture and oxidizer as their energy source. The basic components of a liquid rocket engine include a thrust chamber, a propellant supply system, and an engine control system. The liquid propellant is stored in a propellant tank. When the engine is working, the propellant is delivered to a combustion chamber under the action of the propellant supply system according to the required pressure and flow rate, and is atomized, evaporated, mixed and burned to generate high temperature and high pressure gas, and then accelerated to supersonic speed and discharged through a nozzle to generate thrust.
The hybrid rocket's propellant mainly contains solid fuel and liquid oxidizer. It not only has the capability of controlling the thrust, the feature of system simplicity relatively low cost, but also has higher safety than solid rocket or liquid rocket.
Surrounded by the solid fuel segment 12, a hot gas trajectory 113 is formed in the combustion port 112 to communicate with the nozzle 14 along an axial direction X. During the combustion process, the oxidizer injector 13 injects oxidizer toward the trajectory 113, and after ignition, a diffusion flame is generated in the trajectory 113 along the axial direction X, and the diffusion flame burns the solid fuel segment 12 along the axial direction X.
However, the combustion efficiency of the diffusion flame is different at each position along the trajectory 113, for example, the combustion efficiency of the diffusion flame closer to the nozzle 14 is more efficient, resulting in the solid fuel segment 12 being unable to have uniform regression rate and high combustion efficiency.
An objective of the present invention is to solve the problem that the diffusion flame cannot burn the solid fuel segment with uniform regression rate, and at the time enhancing the combustion efficiency of the hybrid rocket engine.
In order to achieve the aforementioned objective, the present invention is a hybrid rocket engine with an improved solid fuel segment, comprising:
a combustion chamber with a bulkhead surrounding and defining a combustion port, one end of the bulkhead being disposed with an oxidizer injector, and another end opposite to the oxidizer injector being disposed with a nozzle, and a direction of the oxidizer injector extending to the nozzle is an axial direction; and
a solid fuel segment installed in the combustion port and located on the bulkhead, on the solid fuel segment being disposed with a plurality of protrusions along the axial direction, the protrusion having a protrusion top surface, a first distance being between the protrusion top surface and the bulkhead, and a recess being formed between the each two protrusions, the recess having a recess top surface, a second distance being between the recess top surface and the bulkhead, and the first distance being greater than the second distance.
Preferably, the nozzle has a nozzle throat, the nozzle throat has a radial length extending along a radial direction, that is the nozzle throat diameter, a length of the first distance is 10% to 50% of the radial length.
In order to achieve the aforementioned objective, a second embodiment of the present invention is a rocket engine with an improved solid fuel segment, comprising:
a combustion chamber with a bulkhead surrounding and defining a combustion port, one end of the bulkhead is disposed with an oxidizer injector, and another end opposite to the oxidizer injector being disposed with a nozzle, and a direction of the oxidizer injector extending to the nozzle is an axial direction; and
a solid fuel segment installed in the combustion chamber and located on the bulkhead, on the solid fuel segment being disposed with a plurality of protrusions along the axial direction, the protrusion having a protrusion top surface, and a recess being formed between each of the two protrusions, and each of the recesses having a flame holding hot-gas region.
Preferably, each of the protrusion top surfaces respectively has a first length along the extending direction, and one end of the combustion chamber extends to another end is a second length, and each of the first lengths is 5% to 25% of a total length of the second length.
Preferably, the oxidizer injector comprises a body, the body has a feed passage as well as a first runner assembly and a second runner assembly communicating with the feed passage. The feed passage has an axis, the first runner assembly and the second runner assembly are sequentially arranged along the axis. The first runner assembly has a plurality of forward runners, and the second runner assembly has a plurality of reverse runners, each of the forward runners is disposed along a forward running direction, and each of the reverse runners is disposed along a reverse running direction. One of the forward running directions is defined as a first forward running direction, and one of the reverse running directions is defined as a first reverse running direction. The first forward running direction and the first reverse running direction extend and a position of intersection is an intersection point, and an extending direction of the intersection point connecting with the axis is a central axis, the first forward runner is on one side of the central axis, and the first reverse runner is on another side of the central axis. A forward angle is formed between the first forward running direction and the central axis, a reverse angle is formed between the first reverse running direction and the central axis, and an absolute value of the forward angle and an absolute value of the reverse angle are equal.
Preferably, the absolute value of the forward angle and the absolute value of the reverse angle are between 20 and 80 degrees.
Preferably, the body has an inner wall surface facing the feed passage, an injection angle is formed between each of the forward runners and the inner wall surface, as well as between each of the reverse runners and the inner wall surface, the injection angle is located on a side close to the combustion chamber, and the injection angle is between 20 and 90 degrees.
In order to achieve the aforementioned objective, a third embodiment of the present invention is a rocket engine with an improved solid fuel segment, comprising:
a combustion chamber
a solid fuel segment installed in the combustion chamber; and
an oxidizer injector installed in the combustion chamber, the oxidizer injector injecting an oxidizer into the combustion chamber, and generating a plurality of flame holding hot-gas regions along the diffusion flame structure on the solid fuel segment evenly.
By forming the diffusion flame with flame holding hot-gas regions on the solid fuel segment surface, a more uniform regression rate of the solid fuel segment can be maintained from ignition through certain burn time. Therefore, high combustion efficiency is established from engine startup and maintained later on by the oxidizer injection mechanism provided by the injector when the port diameter is enlarged.
The foregoing and other technical contents, features and effects of the present invention to achieve the above object will be clearly presented in the following detailed description of the preferred embodiments with reference to the drawings.
Please refer to
The combustion chamber 20 has a bulkhead 21 surrounding and defining a combustion port 22, one end of the bulkhead 21 is disposed with an oxidizer injector 30, and another end opposite to the oxidizer injector 30 is disposed with a nozzle 40, and a direction of the oxidizer injector 30 extending to the nozzle 40 is an axial direction X′. In the present embodiment, the oxidizer injector 30 is disposed in the combustion port 22, and the oxidizer injector 30 injects oxidizer along the axial direction X′.
The solid fuel segment 50 is installed in the combustion port 22 and located on the bulkhead 21, on the solid fuel segment 50 is disposed with a plurality of protrusions 51 along the axial direction X′, the protrusion 51 has a protrusion top surface 511, a first distance M1 is between the protrusion top surface 511 and the bulkhead 21, and a recess 52 is formed between the each two protrusions 51, the recess 52 has a recess top surface 521, a second distance M2 is between the recess top surface 521 and the bulkhead 21, and the first distance M1 is greater than the second distance M2.
In this embodiment, each of the protrusions 51 respectively has a diffusion flame surface 512 facing the nozzle 40, and a flame holding hot-gas region 53 is formed between each of the diffusion flame surfaces 512 and the connected recess top surface 521, respectively.
Preferably, two ends the nozzle 40 respectively have a nozzle convergent section 41 connected to the combustion chamber 20, and a nozzle throat 42 opposite to the nozzle convergent section 41. The nozzle throat 42 has a radial length W1 extending along a radial direction, a length of the first distance M1 is 10% to 50% of the radial length W1. By limiting the length of the first distance M1 to 10% to 50% of the radial length W1, thereby allowing the solid fuel segment 50 to be more easily formed on the bulkhead 21 while maintaining the flame holding hot-gas regions 53 to even the regression rate of the solid fuel segment 50.
Preferably, each of the protrusion top surfaces 511 respectively has a first length N1 along the extending direction, and one end of the combustion chamber 20 extends to another end is a second length N2, and each of the first lengths N1 is 5% to 25% of a total length of the second length N2.
The above is the structural configuration and connection relationship of the present invention in a first embodiment, and the operation manner of the present invention is as follows.
Referring to
Referring to
Preferably, in the second embodiment, each of the protrusions 51 respectively has the diffusion flame surface 512 facing the nozzle 40, and the flame holding hot-gas region 53 is formed between each of the diffusion flame surfaces 512 and the connected recess top surface 521, respectively. When the propellant mixture passes through the flame holding hot-gas regions 53, eddies are formed, so that the propellant mixture has better combustion efficiency as it passes through the flame holding hot-gas regions 53.
Referring to
Referring to
In particular, the absolute value of the forward angle θ1 and the absolute value of the reverse angle θ2 are between 20 and 80 degrees to obtain an optimum combustion efficiency.
Preferably, the oxidizer injector 30 has an inner wall surface 34 facing the feed passage 31, an injection angle θ3 is formed between each of the forward runners 321 and the inner wall surface 34, as well as between each of the reverse runners 331 and the inner wall surface 34, the injection angle θ3 is located on a side close to the combustion chamber 20, and the injection angle θ3 is between 20 and 90 degrees to obtain an optimum combustion efficiency.
Preferably, as shown in
In summary, the above embodiments and drawings are merely the preferred embodiments of the present invention, and the scope of implementation of the present invention is not limited thereto. In other words, all the equivalent changes and modifications made according to the appended claims shall still fall within the scope covered by the appended claims of the present invention.
