CN115263605B - Pintle injector, rocket motor and liquid rocket - Google Patents
Pintle injector, rocket motor and liquid rocket Download PDFInfo
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- CN115263605B CN115263605B CN202211186786.1A CN202211186786A CN115263605B CN 115263605 B CN115263605 B CN 115263605B CN 202211186786 A CN202211186786 A CN 202211186786A CN 115263605 B CN115263605 B CN 115263605B
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02K—JET-PROPULSION PLANTS
- F02K9/00—Rocket-engine plants, i.e. plants carrying both fuel and oxidant therefor; Control thereof
- F02K9/42—Rocket-engine plants, i.e. plants carrying both fuel and oxidant therefor; Control thereof using liquid or gaseous propellants
- F02K9/44—Feeding propellants
- F02K9/52—Injectors
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Abstract
The invention provides a pintle injector, a rocket motor and a liquid rocket. The pintle injector includes: the pintle inner cylinder is provided with a central flow passage; the pintle head is arranged at the end part of the pintle inner cylinder, a first nozzle is limited by the pintle head and the pintle inner cylinder, a cooling flow channel is formed at the pintle head, one end of the cooling flow channel is communicated with the central flow channel, and a cooling outlet is formed at the other end of the cooling flow channel; a cooling device is arranged in the cooling flow channel, a second nozzle is limited by the cooling device and the cooling outlet, and a jet flow channel is limited by the cooling device and the outer surface of the head of the pintle; the second nozzle sprays the outer surface of the pintle head through the spray flow passage, and forms a liquid film for cooling on the outer surface of the pintle head. According to the pintle injector provided by the invention, the propellant can form a liquid film cooling structure on the outer surface of the pintle head, so that better cooling and protection are realized, the outer surface of the pintle head is prevented from being ablated at high temperature, and the design of low cost, high reliability and high combustion efficiency is realized.
Description
Technical Field
The invention relates to the technical field of rockets, in particular to a pintle injector, a rocket engine and a liquid rocket.
Background
In the related art, a pintle injector is proposed in the fifties of the twentieth century and is widely applied to injectors of liquid rocket engines at present. As can be seen from data and numerical simulation results obtained by a plurality of experiments of experts in the field, due to the unique structural form of the pintle injector, two large backflow regions are formed in the combustion chamber, wherein one large backflow region is an upper backflow region and is positioned near the concave dome of the top cover, and the other large backflow region is a central backflow region and is positioned in the central region of the head end of the pintle. Generally, the upper recirculation zone is at a lower temperature and therefore the usual metallic materials can be tolerated without additional cooling, while the problem of ablation of the pintle head is prevalent in the thermal testing of the pintle injector, since the temperature of the central recirculation zone is very high and its side zones are also progressively higher along the thrust chamber axis.
The existing pintle injectors generally employ several cooling methods: firstly, the head end of the pintle is processed into a thin-wall semicircular structure through finish machining; secondly, selecting high-temperature-resistant alloy to resist heat or conducting away heat flow by using high-thermal-conductivity materials such as zirconium copper and the like; thirdly, the head end of the pintle is beaten with direct current micro-holes to spray fuel to mutually hit into a fog fan to block hot gas; fourthly, the head end of the pintle is directly made of porous materials to form the cooling panel for sweating.
However, the above methods have high requirements on machining precision and cost, and some cooling methods need to use precious metal materials, for example, for the first cooling method, the requirement on structural strength is higher due to higher pressure of the combustion chamber of the high-thrust liquid rocket engine, so that the thin-wall semicircular structure is difficult to realize in the manufacturing process of the pintle head end; for the second cooling method, expensive metal materials are required, which is more costly; for the third cooling mode, the direct hole impingement cooling mode needs more than 5% of fuel to effectively protect the pintle head end, which will have a large impact on the efficiency of the combustion apparatus.
Disclosure of Invention
The invention provides a pintle injector, a rocket engine and a liquid rocket, which are used for solving the defect that the head of a pintle is easy to be ablated at high temperature in the prior art and realizing the following technical effects: the cooling and protection effects are better, and the problem that the outer surface of the pintle head is ablated by high temperature is solved.
A pintle injector according to an embodiment of the first aspect of the invention, comprising:
the inner cylinder of the pintle is internally provided with a central flow passage;
the pintle head is arranged at the end part of the pintle inner cylinder, a first nozzle communicated with the central flow passage is defined between the pintle head and the pintle inner cylinder, a cooling flow passage is formed in the pintle head, one end of the cooling flow passage is communicated with the central flow passage, and the other end of the cooling flow passage forms a cooling outlet;
a cooling device is arranged in the cooling flow channel, an annular second nozzle is defined between the cooling device and the cooling outlet, an annular spraying flow channel is defined between the cooling device and the outer surface of the pintle head, the outer periphery of the spraying flow channel is outwards opened and faces the outer surface of the pintle head, and the inner periphery of the spraying flow channel is communicated with the second nozzle;
the second nozzle sprays the liquid to the outer surface of the pintle head through the spray flow passage, and forms a liquid film for cooling on the outer surface of the pintle head.
According to one embodiment of the present invention, the cooling device includes a main body portion and a spattering portion fixed to a tip end of the main body portion, the main body portion being installed in the cooling flow passage and defining the second nozzle with the cooling outlet;
the sputtering part is fixed at the tail end of the main body part, the sputtering part covers the second nozzle, the sputtering part and the outer surface of the pintle head part jointly define the injection flow channel, and the injection flow channel extends along the outer surface of the pintle head part towards the direction far away from the main body part.
According to one embodiment of the invention, a side surface of the sputtering portion facing the main body portion forms a flow guide surface, and a bending direction of the flow guide surface is the same as a bending direction of an outer surface of the pintle head portion.
According to an embodiment of the invention, the flow guiding surface and the outer surface of the pintle head are both curved upwards, and the curvature of the flow guiding surface is greater than or equal to the curvature of the outer surface of the pintle head.
According to one embodiment of the invention, the main body part comprises a vortex section, the outer peripheral surface of which is provided with an external thread;
the cooling flow passage is provided with a vortex chamber, the vortex section is arranged in the vortex chamber, the vortex section and the vortex chamber jointly define a spiral vortex flow passage, and the vortex flow passage is communicated with the second nozzle.
According to one embodiment of the invention, the number of turns of the external thread is 3, and/or the lead of the external thread is in the range of 20 to 30.
According to one embodiment of the invention, the diameter of the sputtering portion is 1.5 to 2 times the diameter of the vortex chamber.
According to one embodiment of the invention, the main body part further comprises a cut-off section provided with a cut-off hole therethrough;
the cooling flow passage is provided with a flow interception chamber, the flow interception chamber is positioned at the upstream of the vortex chamber in the flowing direction of liquid, the flow interception section is fixedly installed in the flow interception chamber, and the flow interception hole is communicated with the vortex flow passage.
According to one embodiment of the invention, the number of the intercepting holes is multiple, and the intercepting holes are uniformly distributed at intervals along the circumferential direction of the intercepting section.
According to one embodiment of the invention, the central axis of the cooling flow channel coincides with the central axis of the pintle head.
A rocket engine according to a second aspect of the present invention comprises:
a pintle injector according to embodiments of the first aspect of the invention.
A liquid rocket according to an embodiment of the third aspect of the present invention includes:
a rocket engine as recited in the second aspect of the present invention.
In summary, according to the pintle injector provided by the embodiment of the invention, the cooling flow channel and the cooling device are arranged on the pintle head, so that the propellant can form a liquid film cooling structure on the outer surface of the pintle head, thereby achieving better cooling and protection effects, solving the problem that the outer surface of the pintle head is ablated by high temperature, and in addition, the pintle injector provided by the invention can effectively cool the pintle head by only small fuel flow on the premise of not changing a metal material and ensuring the integral strength and rigidity of the pintle injector, thereby realizing the pintle injector design with low cost, high reliability and high combustion efficiency.
Drawings
In order to more clearly illustrate the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a schematic cross-sectional view of a pintle injector provided herein;
FIG. 2 is an enlarged partial schematic view of a pintle injector provided by the present invention;
FIG. 3 is a schematic view of the cooling apparatus provided in the present invention;
fig. 4 is a schematic cross-sectional view of a cooling device provided by the present invention.
Reference numerals are as follows:
1. a pintle inner barrel; 11. a center flow passage; 12. a first nozzle;
2. a pintle head; 21. a cooling flow channel; 211. a cooling outlet; 212. a second nozzle; 213. a vortex chamber; 22. an injection flow channel; 23. an outer surface of the pintle head;
31. a sputtering section; 311. a flow guide surface; 32. a vortex section; 321. an external thread; 33. a flow interception segment; 331. and (4) an intercepting hole.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without inventive step based on the embodiments of the present invention, are within the scope of protection of the present invention.
In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the embodiments of the present invention and simplifying the description, but do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the embodiments of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the embodiments of the present invention, it should be noted that, unless explicitly stated or limited otherwise, the terms "connected" and "connected" are to be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. Specific meanings of the above terms in the embodiments of the present invention may be understood as specific cases by those of ordinary skill in the art.
In embodiments of the invention, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature "under," "beneath," and "under" a second feature may be directly under or obliquely under the second feature, or may simply mean that the first feature is at a lesser elevation than the second feature.
In the description of the present specification, reference to the description of "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Moreover, various embodiments or examples and features of various embodiments or examples described in this specification can be combined and combined by one skilled in the art without being mutually inconsistent.
A pintle injector, a rocket motor having the pintle injector, and a liquid rocket having the rocket motor provided in the present invention will be described below with reference to the accompanying drawings.
A pintle injector according to an embodiment of the first aspect of the invention, as shown in fig. 1 to 4, comprises a pintle inner barrel 1 and a pintle head 2.
The pintle inner barrel 1 is formed with a central flow passage 11 therein. The pintle head 2 is mounted at the end of the pintle inner barrel 1, a first nozzle 12 communicating with the central flow passage 11 is defined between the pintle head 2 and the pintle inner barrel 1, a cooling flow passage 21 is formed in the pintle head 2, one end of the cooling flow passage 21 communicates with the central flow passage 11, and the other end of the cooling flow passage 21 forms a cooling outlet 211.
The cooling channel 21 is internally provided with a cooling device, the cooling device and the cooling outlet 211 jointly define an annular second nozzle 212, the cooling device and the outer surface 23 of the pintle head 2 define an annular injection channel 22, the outer periphery of the injection channel 22 is opened outwards and faces the outer surface 23 of the pintle head 2, and the inner periphery of the injection channel 22 is communicated with the second nozzle 212.
The second nozzle 212 sprays the outer surface 23 of the pintle head 2 through the spray passage 22, and forms a liquid film for cooling on the outer surface 23 of the pintle head 2.
According to the pintle injector of the embodiment of the present invention, the "outer surface 23 of the pintle head 2" refers to the surface of the pintle head 2 exposed outside the central flow passage 11 that is at risk of high temperature ablation, in particular, the outer surface 23 of the pintle head 2 may be referred to as the bottom surface of the pintle head 2 in certain specific scenarios. Injection flow channel 22 is hollow and cylindrical as a whole, and the outer periphery of injection flow channel 22 (i.e., the outer peripheral edge of injection flow channel 22) is opened as a whole, and the inner periphery of injection flow channel 22 (i.e., the inner peripheral edge of injection flow channel 22) is also opened as a whole, and the propellant injected from second nozzle 212 enters from the inner periphery of injection flow channel 22 and is injected from the outer periphery of injection flow channel 22.
As shown in FIG. 1, the specific working principle of the pintle injector provided by the present invention is as follows: after the propellant enters the central flow channel 11 of the pintle inner barrel 1, the propellant flows along the central flow channel 11 to the vicinity of the pintle head 2, wherein the propellant is divided into two parts at the pintle head 2, most of the propellant is sprayed out through the first nozzle 12 at the edge of the pintle head 2 and is combusted in the combustion chamber as fuel, and a small part of the propellant enters the cooling flow channel 21 in the pintle head 2, is sprayed out of the cooling flow channel 21 through the second nozzle 212 after being cooled in the cooling flow channel 21, and is sprayed onto the outer surface 23 of the pintle head 2 under the guiding action of the spray flow channel 22, so that the cooled propellant forms a liquid film on the outer surface 23 of the pintle head 2, so that the liquid film can play a role of cooling and protection during the operation of the pintle injector, the outer surface 23 of the pintle head 2 is prevented from being ablated by high temperature, and the cooling device and the presence of the cooling flow channel 21 can form a liquid film cooling structure on the outer surface 23 of the pintle head 2 by a small flow rate of the propellant, thereby achieving a better cooling effect and enabling the loss of the propellant as a small fuel quantity loss, thereby ensuring the combustion efficiency of the engine.
In summary, according to the pintle injector provided by the embodiment of the invention, the cooling flow channel 21 and the cooling device are arranged on the pintle head 2, so that the propellant can form a liquid film cooling structure on the outer surface 23 of the pintle head 2, thereby achieving better cooling and protection effects, solving the problem that the outer surface 23 of the pintle head 2 is ablated by high temperature, and in addition, the pintle injector provided by the invention can effectively cool the pintle head 2 only by small fuel flow on the premise of ensuring the integral strength and rigidity without changing a metal material, thereby realizing the design of the pintle injector with low cost, high reliability and high combustion efficiency.
In the related art, a pintle injector is proposed in the fifties of the twentieth century and is widely applied to injectors of liquid rocket engines at present. As can be seen from data and numerical simulation results obtained by a plurality of experiments of experts in the field, due to the unique structural form of the pintle injector, two large backflow regions are formed in the combustion chamber, wherein one large backflow region is an upper backflow region and is positioned near the concave dome of the top cover, and the other large backflow region is a central backflow region and is positioned in the central region of the head end of the pintle. Generally, the upper recirculation zone is at a lower temperature and therefore the usual metallic materials can be tolerated without additional cooling, while the problem of ablation of the pintle head is prevalent in the thermal testing of the pintle injector, since the temperature of the central recirculation zone is very high and its side zones are also progressively higher along the thrust chamber axis.
The existing pintle injectors generally employ several cooling methods: firstly, the head end of the pintle is processed into a thin-wall semicircular structure through finish machining; secondly, high-temperature resistant alloy is selected for heat resistance or high-thermal-conductivity materials such as zirconium copper are used for conducting away heat flow; thirdly, the head end of the pintle is punched with direct current micro-holes to spray fuel so that the direct current micro-holes are mutually impacted to form a fog fan to block hot gas; fourthly, the head end of the pintle is directly made of porous materials to form the cooling panel for sweating.
However, the above methods have high requirements on machining precision and cost, and some cooling methods need to use precious metal materials, for example, for the first cooling method, the requirement on structural strength is higher due to higher pressure of the combustion chamber of the high-thrust liquid rocket engine, so that the thin-wall semicircular structure is difficult to realize in the manufacturing process of the pintle head end; for the second cooling method, expensive metal materials are needed, and the cost is higher; for the third cooling mode, the direct hole impingement cooling mode requires more than 5% of fuel to effectively protect the pintle head, which will have a large impact on the efficiency of the combustion apparatus.
In order to solve the technical drawbacks of the related art, the present invention provides a pintle injector, which is distinguished from the conventional pintle cooling structure in that a small flow of propellant is injected from the second nozzle 212 and is guided to the outer surface 23 of the pintle head 2 through the injection flow passage 22, thereby forming a uniformly distributed liquid film structure on the outer surface 23 of the pintle head 2, which prevents high-temperature ablation of the pintle head 2.
In addition, compared with the pintle injector without additional cooling, the pintle injector provided by the invention can effectively reduce the heat flow density of the pintle head 2 and solve the common problem that the pintle head 2 is easy to ablate. Compared with other heat protection modes (such as drilling, cooling by 'sweating' or cooling by using other materials with heat resistance and heat conduction), the pintle injector has the advantages of small processing difficulty, low processing cost, easiness in disassembly and replacement, easiness in detection and easiness in test.
Further, the pintle injector of the present invention also has the advantage of requiring a lower flow rate and less combustion efficiency than other methods of cooling the pintle head 2 by the propellant itself, typically requiring less than 1% of the total amount of propellant to cool the pintle head.
As shown in fig. 2 to 4, according to one embodiment of the present invention, the cooling device includes a main body part and a sputtering part 31, the sputtering part 31 is fixed to a distal end of the main body part, and the main body part is installed in the cooling flow passage 21 and defines the second nozzle 212 with the cooling outlet 211.
The sputtering section 31 is fixed to the end of the main body section, the sputtering section 31 covers the second nozzle 212, and the sputtering section 31 and the outer surface 23 of the pintle head 2 together define the injection flow passage 22, the injection flow passage 22 extending along the outer surface 23 of the pintle head 2 in a direction away from the main body section.
In this way, the propellant discharged from the second nozzle 212 enters the injection flow path 22 by being blocked by the splash part 31, and is discharged in a direction away from the main body part along the outer surface 23 of the pintle head 2 by the guiding action of the injection flow path 22, and the propellant covers the outer surface 23 of the pintle head 2 and forms a liquid film for cooling during the discharge of the propellant, thereby preventing the pintle head 2 from being ablated by high temperature.
In some embodiments, the sputtering portion 31 may be a circular sputtering plate having a diameter larger than that of the cooling outlet 211, such that the second nozzle 212 is completely covered by the sputtering plate, the annular injection flow channel 22 is defined between the sputtering plate and the bottom surface of the pintle head 2, and both the inner side and the outer side of the injection flow channel 22 are open. Furthermore, in some embodiments, the cooling device is mushroom-shaped overall, with the body forming the stem and the splash section 31 forming the umbrella body.
Of course, the above embodiments are only some of the embodiments of the present invention, and do not constitute a specific limitation to the cooling device of the present invention, wherein the main body portion and the sputtering portion 31 of the cooling device may also have other structural shapes, and the present invention is not limited thereto as long as the second nozzle 212 and the injection flow passage 22 can be formed between the cooling device and the pintle head portion 2.
As shown in fig. 2 to 4, according to one embodiment of the present invention, a side surface of the sputtering portion 31 facing the main body portion forms a flow guide surface 311, and a bending direction of the flow guide surface 311 is the same as a bending direction of the outer surface 23 of the pintle head portion 2.
In this way, the deflector surface 311 can deflect the propellant during its flow in the injection channel 22, so that the propellant can be smoothly and accurately sprayed onto the outer surface 23 of the pintle head 2. For example, if the bottom surface of the pintle head 2 is curved upward, the flow guide surface 311 is also curved upward; if the bottom surface of the pintle head 2 is curved downward, the deflector surface 311 is also curved downward.
As shown in fig. 2 to 4, in one embodiment of the present invention, the guiding surface 311 and the outer surface 23 of the pintle head 2 are both curved upward, and the curvature of the guiding surface 311 is greater than or equal to the curvature of the outer surface 23 of the pintle head 2.
In another embodiment of the present invention, the guiding surface 311 and the outer surface 23 of the pintle head 2 are both curved downward, and the curvature of the guiding surface 311 is less than or equal to the curvature of the outer surface 23 of the pintle head 2.
In the above two embodiments, the curvature of the flow guiding surface 311 is limited, so that the propellant can be ejected toward the outer surface 23 of the pintle head 2, and the ejection track of the propellant can cover the entire outer surface of the pintle head 2, thereby avoiding the blank area on the outer surface 23 of the pintle head 2, which is not covered by the liquid film.
As shown in fig. 1, according to an embodiment of the present invention, the main body portion includes a vortex section 32, and an outer circumferential surface of the vortex section 32 is provided with an external thread 321.
The cooling flow channel 21 forms a swirl chamber 213, the swirl section 32 is mounted in the swirl chamber 213, and the swirl section 32 and the swirl chamber 213 together define a helical swirl flow channel (not shown) which communicates with the second nozzle 212.
In this embodiment, after the propellant enters the swirl chamber 213, a downward spiral swirl is formed under the guiding action of the external thread 321, and the swirl is ejected from the second nozzle 212 along the swirl flow channel, it can be understood that the propellant ejected from the second nozzle 212 has a larger circumferential linear velocity due to the action of the swirl, so that the propellant can be in a structure of rotation in a gyro type and is outwardly diverged to be ejected from the ejection flow channel 22, and thus the propellant can be more uniformly sprayed on the outer surface 23 of the pintle head 2, so that the distribution of the liquid film on the outer surface 23 of the pintle head 2 is more uniform, and in addition, the use amount of the propellant required by the liquid film formation can be further reduced by adopting the above swirl structure, thereby further ensuring the combustion performance of the engine.
Compared with other ways of utilizing the propellant to cool, the invention uses the rotational flow centrifugal device (namely the structure of the vortex section 32) to enable a small amount of cooling medium to form a thin annular liquid film which is uniformly and effectively pasted on the bottom cambered surface of the pintle head 2, and the liquid film can also continuously wrap the pintle head 2 through gasification extension, thereby carrying out uniform and good thermal protection on the pintle head 2.
According to an embodiment of the present invention, the number of the threads of the external thread 321 is 3, and/or the lead of the external thread 321 is in the range of 20 to 30. The parameters are obtained by the inventor through multiple experiments and simulation summarization, and the external thread 321 has a better flow guide effect under the condition of adopting the parameter structure, and is simple in structure and convenient to manufacture.
Of course, the number of the spiral lines and the lead of the external thread 321 are not particularly limited in the present invention, and the number of the spiral lines and the lead of the external thread 321 may be in other parameter ranges.
According to one embodiment of the present invention, the diameter of the sputtering portion 31 takes 1.5 times to 2 times the diameter of the swirl chamber 213. Furthermore, the length and diameter of the swirl section 32 is typically one tenth of the overall diameter of the pintle inner barrel 1. The above parameters are obtained by the inventor through multiple experiments and simulation summarization, and the cooling device has a better liquid film spraying effect, a simple structure and convenience in manufacturing under the condition of adopting the above size structure.
Of course, the specific size of the cooling device is not particularly limited in the present invention, and other sizes of the cooling device may be adopted. For example, a manufacturer may set different sized cooling devices as desired by a user.
As shown in fig. 2 to 4, according to an embodiment of the present invention, the main body portion further includes the cut-off section 33, and the cut-off section 33 is provided with a cut-off hole 331 penetrating the entire cut-off section 33.
The cooling flow passage 21 is provided with a cutoff chamber (not shown) which is located upstream of the vortex chamber 213 in the flow direction of the liquid, the cutoff section 33 is fixedly installed in the cutoff chamber, and the cutoff hole 331 communicates with the vortex flow passage.
In the present embodiment, after entering the cooling flow channel 21, the propellant first enters the cutoff chamber, flows to the swirl chamber 213 through the cutoff hole 331 on the cutoff section 33, is ejected out of the second nozzle 212 along the swirl flow channel, and is finally sprayed on the outer surface 23 of the pintle head 2 under the guiding action of the ejection flow channel 22 to form a liquid film for cooling. Therefore, the intercepting hole 331 can play a role in controlling the flow of the propellant, namely the flow of the propellant can be changed by designing different sizes of the intercepting hole 331, so that the intercepting effect is achieved, the phenomenon that the combustion performance of the engine is influenced due to overlarge flow of the propellant in the cooling flow channel 21 is avoided, the normal work of the engine is ensured, and the cooling and the protection of the pintle head 2 are realized by using smaller flow of the propellant.
In some embodiments of the present invention, the number of the intercepting hole 331 is plural, and the plural intercepting holes 331 are uniformly and spaced apart along the circumference of the intercepting section 33. In this way, by providing a plurality of circumferentially distributed cutoff holes 331, the distribution of the propellant after entering the swirl chamber 213 may be more uniform, and further, the distribution of the propellant after exiting the second nozzle 212 may be more uniform, thereby improving the uniformity of the distribution of the liquid film on the outer surface 23 of the pintle head 2.
Of course, the above-mentioned embodiment is only one of many embodiments of the present invention, and does not constitute a specific limitation to the intercepting hole 331 of the present invention, wherein the number of the intercepting holes 331 may be one, two or more, and the plurality of intercepting holes 331 may also be distributed on the intercepting section 33 in other distribution structures besides the above-mentioned embodiments, and the present invention is not limited thereto.
According to one embodiment of the invention the central axis of the cooling channel 21 coincides with the central axis of the pintle head 2.
An embodiment of the pintle injector according to the present invention is described below with reference to the accompanying drawings.
As shown in fig. 1 to 4, a pintle injector includes a pintle inner barrel 1 and a pintle head 2.
The pintle inner barrel 1 is formed with a central flow passage 11 therein. The pintle head 2 is mounted at the end of the pintle inner barrel 1, a first nozzle 12 communicating with the central flow passage 11 is defined between the pintle head 2 and the pintle inner barrel 1, a cooling flow passage 21 is formed in the pintle head 2, one end of the cooling flow passage 21 communicates with the central flow passage 11, and the other end of the cooling flow passage 21 forms a cooling outlet 211.
The cooling flow channel 21 is internally provided with a cooling device, the cooling flow channel 21 is sequentially provided with a cut-off chamber, a vortex chamber 213 and a cooling outlet 211 from top to bottom, and the cooling device is sequentially composed of a cut-off section 33, a vortex section 32 and a sputtering part 31 from top to bottom. The intercepting section 33 is screwed into the intercepting chamber, and a plurality of intercepting holes 331 are formed in the intercepting section 33; the vortex section 32 is positioned in the vortex chamber 213, the vortex section 32 is provided with external threads 321, and a vortex flow passage which is downward spirally is defined between the external threads 321 and the vortex chamber 213.
The sputtering part 31 is in a circular plate shape, the sputtering part 31 completely covers the cooling outlet 211, the sputtering part 31 and the bottom surface of the pintle head 2 jointly define an annular injection flow channel 22, and the inner side and the outer side of the injection flow channel 22 are both open. The upper surface of the sputtering part 31 forms a flow guide surface 311, the flow guide surface 311 and the bottom surface of the pintle head 2 are both bent upwards, and the bending radian of the flow guide surface 311 is greater than that of the bottom surface of the pintle head 2.
After entering the cooling flow channel 21 from the inlet of the cooling flow channel 21, the propellant flows through the cutoff flow hole 331, the vortex flow channel and the second nozzle 212 in sequence, and is finally sprayed onto the bottom surface of the pintle head 2 under the guiding action of the spray flow channel 22, so that a uniform liquid film is formed on the bottom surface of the pintle head 2, and the pintle head 2 is prevented from being ablated at high temperature.
The selection of specific dimensional parameters for the pintle injector in this embodiment is described below.
In the present invention, by adjusting the aperture, aspect ratio and inlet-outlet structure of the cutoff hole 331, the medium flow rate through the cooling device can be calculated by pressure drop; further, by adjusting the width D of the injection flow path 22, the ejection direction of the liquid film and the thickness of the liquid film can be adjusted, thereby forming a cooling liquid film suitable for the condition of the combustion chamber.
Specifically, the calculation process of the parameters of the intercepting hole 331 is described as follows, wherein the parameters required in the calculation process are respectively: l is the length of the shut-off hole 331;
mass flow for a single shut-off hole 331;
is the pressure drop of the shut-off hole 331;
and
density and kinematic viscosity of the medium, respectively;
is the flow coefficient; d is the equivalent diameter of the shut-off hole 331;
the fluid flow velocity and reynolds number of the shut-off hole 331, respectively;
is the coefficient of friction;
is a hydraulic loss coefficient, and
respectively water conservancy loss coefficient
Constituent elements of, i.e. hydraulic loss coefficient
Are respectively composed of
To form the composition.
When the structural form, mass flow rate, pressure drop and physical properties of the propellant of the intercepting hole 331 are known, the L/d,
、
、
And
in the case of (2), the size of the intercepting hole 331 needs to be iteratively calculated a plurality of times, and in the iterative calculation process, except for L/d,
、
、
And
other parameters than L, d,
Equal parameters) may change over time with iterative calculations, wherein, for ease of description,
the isoparameters respectively represent the calculation results of the first iteration calculation,
the equal parameters respectively represent the calculation results of the second iteration calculation, and so on.
The specific design calculation process of the cutoff hole 331 is as follows:
(a) Preliminary determination of the flow coefficient of the cutoff orifice 331 by table lookup
Comprises the following steps:
(b) Preliminary
(c) The preliminary fluid flow velocity and reynolds number of the cutoff flow hole 331 are calculated as:
(d) Calculating the friction coefficient and the friction hydraulic loss coefficient as follows:
(e) By
And checking out the picture
And the post-calculation water conservancy loss coefficient is as follows:
(f) The calculated flow coefficient is:
(g) Substituting the above result into step (b) and performing a new iterative calculation to obtain a new result
And comparing the result with the result of the last iterative calculation, judging whether the result is accurate, and continuing to perform the next iterative calculation.
Furthermore, for numerical calculations of other dimensions of the pintle injector of the present invention, the parameter calculations of the swirl section 32 may be referenced to a swirler-type centrifugal nozzle calculation formula; the distance D between the outlet of the sputtering section 31 and the pintle head 2 can be obtained by calculating the medium outlet flow rate, which is typically 5-15 m/s depending on the cooling medium properties.
A rocket engine according to an embodiment of the second aspect of the present invention comprises a pintle injector as described in the embodiment of the first aspect of the present invention.
A liquid rocket according to an embodiment of the third aspect of the invention comprises a rocket motor as described in an embodiment of the second aspect of the invention.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A pintle injector, comprising:
the pintle inner cylinder is internally provided with a central flow passage;
the pintle head is arranged at the end part of the pintle inner cylinder, a first nozzle communicated with the central flow passage is defined between the pintle head and the pintle inner cylinder, a cooling flow passage is formed in the pintle head, one end of the cooling flow passage is communicated with the central flow passage, and the other end of the cooling flow passage forms a cooling outlet;
a cooling device is arranged in the cooling flow channel, an annular second nozzle is defined between the cooling device and the cooling outlet, an annular spraying flow channel is defined between the cooling device and the outer surface of the pintle head, the outer periphery of the spraying flow channel is outwards opened and faces the outer surface of the pintle head, and the inner periphery of the spraying flow channel is communicated with the second nozzle;
the second nozzle is sprayed to the outer surface of the pintle head through the spray flow passage, and forms a liquid film for cooling on the outer surface of the pintle head;
the cooling device comprises a main body part and a sputtering part, the sputtering part is fixed at the tail end of the main body part, and the main body part is installed in the cooling flow channel and defines the second nozzle with the cooling outlet;
the sputtering part is fixed at the tail end of the main body part and covers the second nozzle, the sputtering part and the outer surface of the pintle head part jointly define the injection flow channel, and the injection flow channel extends along the outer surface of the pintle head part towards the direction far away from the main body part;
the main body part comprises a vortex section, and the outer peripheral surface of the vortex section is provided with an external thread;
the cooling flow passage is provided with a vortex chamber, the vortex section is arranged in the vortex chamber, the vortex section and the vortex chamber jointly define a spiral vortex flow passage, and the vortex flow passage is communicated with the second nozzle;
the main body part further comprises a flow intercepting section, the cooling flow channel is provided with a flow intercepting chamber, and the flow intercepting section is fixedly installed in the flow intercepting chamber.
2. The pintle injector of claim 1, wherein a side surface of the splash portion facing the main body portion forms a flow guide surface, and a bending direction of the flow guide surface is the same as a bending direction of an outer surface of the pintle head portion.
3. The pintle injector of claim 2, wherein the deflector surface and the outer surface of the pintle head are both curved upwardly, and the arc of curvature of the deflector surface is greater than or equal to the arc of curvature of the outer surface of the pintle head.
4. The pintle injector of claim 1, wherein the number of spirals of the external thread is 3.
5. The pintle injector of claim 1, wherein the diameter of the splash is between 1.5 and 2 times the diameter of the swirl chamber.
6. A pintle injector as defined in claim 1, wherein the cutout section is provided with a cutout aperture therethrough;
the interception chamber is located upstream of the vortex chamber in the flowing direction of the liquid, and the interception hole is communicated with the vortex flow passage.
7. The pintle injector of claim 6, wherein the number of the cutoff holes is plural, and the plurality of the cutoff holes are uniformly and spaced apart along a circumference of the cutoff section.
8. The pintle injector of any of claims 1 to 7, wherein a central axis of the cooling flow passage coincides with a central axis of the pintle head.
9. A rocket engine, comprising:
a pintle injector as claimed in any one of claims 1 to 8.
10. A liquid rocket, comprising:
a rocket engine as recited in claim 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211186786.1A CN115263605B (en) | 2022-09-28 | 2022-09-28 | Pintle injector, rocket motor and liquid rocket |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211186786.1A CN115263605B (en) | 2022-09-28 | 2022-09-28 | Pintle injector, rocket motor and liquid rocket |
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| Publication Number | Publication Date |
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| CN115263605A CN115263605A (en) | 2022-11-01 |
| CN115263605B true CN115263605B (en) | 2023-03-03 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211186786.1A Active CN115263605B (en) | 2022-09-28 | 2022-09-28 | Pintle injector, rocket motor and liquid rocket |
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3712063A (en) * | 1970-03-24 | 1973-01-23 | Bell Aerospace Corp | Cooled pintle assembly |
| CN103867340A (en) * | 2012-12-12 | 2014-06-18 | 中国人民解放军国防科学技术大学 | Dual-rotational-flow inspirator |
| CN104234870A (en) * | 2014-06-13 | 2014-12-24 | 中国航天科技集团公司第六研究院第十一研究所 | Slotted coaxial pintle type injector thrust chamber |
| CN106939850A (en) * | 2017-03-09 | 2017-07-11 | 上海空间推进研究所 | Monopropellant engine anti-backfire injection device |
| CN112324589A (en) * | 2020-12-02 | 2021-02-05 | 中国人民解放军国防科技大学 | Pintle injector and liquid rocket engine with same |
| CN112610360A (en) * | 2020-12-02 | 2021-04-06 | 中国人民解放军国防科技大学 | Liquid rocket engine and pintle injector thereof |
| CN113374600A (en) * | 2021-06-24 | 2021-09-10 | 北京星际荣耀科技有限责任公司 | Pintle injection device, variable thrust rocket engine and rocket |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6591603B2 (en) * | 2001-03-08 | 2003-07-15 | Trw Inc. | Pintle injector rocket with expansion-deflection nozzle |
-
2022
- 2022-09-28 CN CN202211186786.1A patent/CN115263605B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3712063A (en) * | 1970-03-24 | 1973-01-23 | Bell Aerospace Corp | Cooled pintle assembly |
| CN103867340A (en) * | 2012-12-12 | 2014-06-18 | 中国人民解放军国防科学技术大学 | Dual-rotational-flow inspirator |
| CN104234870A (en) * | 2014-06-13 | 2014-12-24 | 中国航天科技集团公司第六研究院第十一研究所 | Slotted coaxial pintle type injector thrust chamber |
| CN106939850A (en) * | 2017-03-09 | 2017-07-11 | 上海空间推进研究所 | Monopropellant engine anti-backfire injection device |
| CN112324589A (en) * | 2020-12-02 | 2021-02-05 | 中国人民解放军国防科技大学 | Pintle injector and liquid rocket engine with same |
| CN112610360A (en) * | 2020-12-02 | 2021-04-06 | 中国人民解放军国防科技大学 | Liquid rocket engine and pintle injector thereof |
| CN113374600A (en) * | 2021-06-24 | 2021-09-10 | 北京星际荣耀科技有限责任公司 | Pintle injection device, variable thrust rocket engine and rocket |
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|---|---|
| CN115263605A (en) | 2022-11-01 |
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