Modular thrust chamber verification structure and verification method for pintle injector optimization

Abstract

The present invention is to solve the technical problems that in the current process of developing the thrust chamber of the pintle injector, when taking into account high combustion efficiency and reliable cooling of the body, multiple influencing factors need to be considered, the workload of verification is very large, many test runs are required, the development cost is high, and the development cycle is long, and a modular thrust chamber verification structure and verification method for pintle injector optimization are provided. The verification structure replaces the integrated structure of the thrust chamber, and by designing cooling rings of different styles and replacing adjustment rings and extension rings of different thicknesses, multiple influencing factors can be quickly verified, the development cycle of the pintle injector thrust chamber can be significantly shortened, the technical status of the thrust chamber can be quickly determined, and multiple factors can be directly compared under the same combustion field conditions, and the interference caused by product assembly status and measurement system fluctuations can be eliminated. The comparison results are highly accurate and more reliable.

Description

Technical Field

[0001] The present invention belongs to the technical field of liquid rocket engines, and in particular relates to a modular thrust chamber verification structure and a verification method for pintle injector optimization. Background Art

[0002] The concept of pintle injectors was proposed in the 1950s and is currently widely used in variable thrust or fixed thrust liquid rocket engines. Represented by TRW, after nearly sixty years of technological development, many pintle fixed thrust and variable thrust liquid rocket engines have been developed, of which more than sixty pintle engines have been hot-tested. Since the 1990s, research on large-thrust pintle engines such as liquid oxygen / liquid hydrogen and liquid oxygen / kerosene has been focused on, and remarkable results have been achieved in the application of cryogenic propellants and low-cost solutions. Pintle injectors have a simple structure, high structural reliability, and are easy to reuse. Pintle injectors are single injection units. Although they have a simple structure, there are many factors that affect combustion efficiency and body cooling. It is necessary to optimize various influencing factors through test runs to determine a thrust chamber technical solution that can take into account both high combustion efficiency and reliable body cooling.

[0003] The typical flow field structure of the pintle injector is shown in Figure 1 After the center road collides with the outer ring propellant, a spray fan with a certain angle is formed, an upper reflux zone A is formed on the spray fan, and a central reflux zone B is formed below the spray fan. A cooling liquid film is introduced at an appropriate position below the synthetic spray fan to cool the body and ensure reliable cooling of the body.

[0004] During the development process, it is necessary to optimize the angle of the inner wall of the cooling ring, the amount of coolant film, the diameter of the cooling holes, the spacing between the cooling holes, the angle of the cooling holes, etc., to minimize the proportion of the coolant film while ensuring reliable cooling of the body; the upper reflow area scale, the center reflow area scale, the thrust chamber length, the relative distance between the synthetic jet C-impact wall position and the coolant film, the distance between the coolant film and the throat, and other parameters also need to be verified in detail, so as to take into account both combustion efficiency and reliable cooling of the body. More than a dozen factors affect the combustion efficiency and throat temperature of the thrust chamber individually or in combination, and the verification workload is very large, requiring many test runs, high development costs, and a long development cycle. Summary of the invention

[0005] The purpose of the present invention is to solve the technical problems that in the current process of developing the thrust chamber of a pintle injector, multiple influencing factors need to be considered when taking into account high combustion efficiency and reliable cooling of the body, the verification workload is very large, many test runs are required, the development cost is high, and the development cycle is long. A modular thrust chamber verification structure and verification method for pintle injector optimization are provided.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A modular thrust chamber verification structure for pintle injector optimization, which is special in that it includes a pintle injector, an adjustment ring, a cooling ring, an extension ring and a body that are sequentially sealed and connected;

[0008] The pintle injector, the adjusting ring and the cooling ring are connected by bolts;

[0009] The cooling ring, the extension ring and the body are bolted together;

[0010] The angle between the inner side wall of the cooling ring and the radial plane of the body is defined as the first inclination angle based on the axis center of the body of the thrust chamber, and the inner side wall of the cooling ring is provided with at least two different first inclination angles;

[0011] At least two groups of cooling holes are processed at one end of the cooling ring close to the body, and the angle between the axis of the cooling hole and the radial plane of the body is defined as the second inclination angle. The aperture of each cooling hole, the circumferential distance between the cooling holes and the second inclination angle of the cooling holes are all different.

[0012] Furthermore, the inner side wall of the cooling ring is provided with two first inclination angles of different angles, the first inclination angle on one side of the cooling ring is γ, and the first inclination angle on the other side is θ;

[0013] The cooling holes are in two groups, namely, first cooling holes with a second inclination angle α arranged at the end of one side of the cooling ring close to the body, and second cooling holes with a second inclination angle β arranged at the end of the other side of the cooling ring close to the body;

[0014] The cooling ring is provided with a first cooling passage nozzle communicating with the first cooling hole and a second cooling passage nozzle communicating with the second cooling hole.

[0015] Furthermore, the γ and θ are different angle values ​​within the range of 70° to 90°;

[0016] The α and β are different angle values ​​within the range of 90° to 100°;

[0017] The diameter of each cooling hole ranges from 0.3 mm to 2.0 mm;

[0018] The circumferential distance between the cooling holes ranges from 5 mm to 15 mm.

[0019] Furthermore, the pintle injector and the adjustment ring and the adjustment ring and the cooling ring are sealed respectively by a first graphite sealing ring and a second graphite sealing ring;

[0020] The cooling ring and the extension ring, and the extension ring and the body 6 are sealed respectively by a third graphite sealing ring and a fourth graphite sealing ring.

[0021] The present invention also provides a modular thrust chamber verification method for pintle injector optimization, which adopts the above-mentioned modular thrust chamber verification structure for pintle injector optimization, and is special in that it includes the following steps:

[0022] Step 1, setting at least two different first inclination angles on the inner side wall of the cooling ring with the axis center of the thrust chamber body;

[0023] At least two groups of cooling holes with different diameters, circumferential distances between cooling holes, and second inclination angles are processed at one end of the cooling ring close to the body;

[0024] Step 2: Select the initial thickness adjustment ring and extension ring, and connect the modular thrust chamber verification structure; set the initial flow of the cooling path, conduct the first test run verification, measure, record and compare the throat temperatures of cooling holes with different cooling ring inner wall angles, cooling hole diameters, and circumferential distances between cooling holes;

[0025] Step 3: Keep the modular thrust chamber verification structure of step 2 unchanged, change the cooling path flow rate, and conduct test runs and verifications respectively. By measuring, recording and comparing the throat temperatures of cooling holes with different cooling ring inner wall angles, cooling hole diameters, and circumferential distances between cooling holes, the influence trend of different cooling path flow rates on throat temperature is obtained.

[0026] Step 4: According to the influence trend of different cooling path flow rates on throat temperature obtained in step 3, the optimal cooling path flow rate and modular thrust chamber verification structure are selected, and the test run is performed again to measure the throat temperature and combustion efficiency at this time;

[0027] If the throat temperature and combustion efficiency meet the design requirements, the thrust chamber technical status is determined;

[0028] If the throat temperature or combustion efficiency does not meet the design requirements, proceed to step 5;

[0029] Step 5: Return to step 1 by replacing adjustment rings and extension rings of different thicknesses until the throat temperature and combustion efficiency meet the design requirements.

[0030] Furthermore, in step 5, the adjustment ring and the extension ring are replaced according to the following rules:

[0031] a. If the throat temperature measured in step 4 is too high and the combustion efficiency is high, lengthen the adjustment ring and reduce the extension ring, and the reduction value of the extension ring should be greater than the lengthening amount of the adjustment ring;

[0032] b. If the throat temperature measured in step 4 is high and the combustion efficiency is low, lengthen the adjustment ring and reduce the extension ring, and the reduction value of the extension ring should be less than the lengthening amount of the adjustment ring;

[0033] c. If the throat temperature and combustion efficiency measured in step 4 are low, lengthen the extension ring and the adjustment ring.

[0034] Furthermore, the throat temperature is measured by infrared temperature measurement.

[0035] Compared with the prior art, the present invention has the following beneficial technical effects:

[0036] 1. The modular thrust chamber verification structure for pintle injector optimization proposed in the present invention replaces the integrated structure of the thrust chamber. By designing cooling rings of different styles and replacing adjustment rings and extension rings of different thicknesses, it solves the tedious work of completing the initial design based on experience and then redesigning when the results are not ideal after the test run.

[0037] 2. The modular thrust chamber verification method for pintle injector optimization proposed in the present invention can realize rapid verification of multiple influencing factors, significantly shorten the development cycle of the pintle injector thrust chamber, quickly determine the technical status of the thrust chamber, and can complete direct comparison of multiple factors under the same combustion field conditions, eliminating interference caused by product assembly status and measurement system fluctuations. The comparison results are highly accurate and more reliable.

[0038] 3. The modular thrust chamber verification method for pintle injector optimization proposed in the present invention overcomes the technical problems in the current design process, such as the large limitations of design experience under multiple influencing factors, the need for multiple test runs to determine the product status, the long thrust chamber development cycle, and the high development cost. The existing verification method is to compare the effect of the cooling ring angle on the throat temperature in two or more test runs, which may not give a law that conforms to the actual situation due to the problem of measurement accuracy. The structure proposed in the present invention can verify the effect of different cooling ring angles on the throat temperature (or other factors) in the same test run. The measurement system is the same in the same test run, and the measurement data is credible when compared, which can give a clear trend law. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of a typical flow field structure of a plug injector;

[0040] Figure 2 It is a schematic diagram of an embodiment of a modular thrust chamber verification structure optimized for a pintle injector according to the present invention;

[0041] Figure 3 Schematic diagram of the cooling ring structure in an embodiment of the present invention; (rotated 90° to the right)

[0042] Description of reference numerals:

[0043] A-upper reflow zone, B-central reflow zone; C-synthetic jet;

[0044] 1-needle bolt injector, 2-adjusting ring, 3-cooling ring, 4-extension ring, 5-connecting flange, 6-body, 7-first graphite sealing ring, 8-second graphite sealing ring, 9-third graphite sealing ring, 10-fourth graphite sealing ring, 11-first bolt, 12-first gasket, 13-first nut, 14-second bolt, 15-second gasket, 16-second nut, 17-first cooling path nozzle, 18-second cooling path nozzle, 19-first cooling hole, 20-second cooling hole. DETAILED DESCRIPTION

[0045] In order to make the purpose, advantages and features of the present invention clearer, the modular thrust chamber verification structure and verification method for pintle injector optimization proposed by the present invention are further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0046] like Figure 2 As shown, the modular thrust chamber verification structure for pintle injector optimization proposed in this embodiment is to modularize the thrust chamber, connect them together externally, and replace one or more parts to simultaneously verify the effects of different cooling ring inner wall angles, cooling hole angles and other factors on the throat temperature in one test run, so as to obtain an optimized pintle injector thrust chamber that takes into account both high combustion efficiency and cooling performance.

[0047] The modular thrust chamber verification structure for pintle injector optimization proposed in this embodiment includes a pintle injector 1, an adjustment ring 2, a cooling ring 3, an extension ring 4 and a body 6 connected in sequence.

[0048] The pintle injector 1, the adjusting ring 2 and the cooling ring 3 are connected with the first nut 13 through the first bolt 11, and a first gasket 12 is provided between the first bolt 11 and the first nut 13. The pintle injector 1 and the adjusting ring 2 and the adjusting ring 2 and the cooling ring 3 are sealed respectively by the first graphite sealing ring 7 and the second graphite sealing ring 8.

[0049] The cooling ring 3, the extension ring 4 and the body 6 are connected by a second bolt 14 and a second nut 16, and a second gasket 15 is provided between the second bolt 14 and the second nut 16. The cooling ring 3 and the extension ring 4 and the extension ring 4 and the body 6 are sealed by a third graphite sealing ring 9 and a fourth graphite sealing ring 10 respectively.

[0050] During the development process, it is necessary to optimize the inner wall angle of the cooling ring, the amount of coolant film, the cooling hole diameter, the cooling hole spacing, the cooling hole angle, etc., to minimize the cooling film ratio while ensuring reliable cooling of the body; parameters such as the upper reflow zone scale, the center reflow zone scale, the thrust chamber length, the relative distance between the synthetic jet C impact wall position and the cooling film, and the distance between the cooling film and the throat also need to be verified in detail, so as to take into account both combustion efficiency and reliable cooling of the body.

[0051] By replacing different adjustment rings 2, the size of the upper recirculation zone, the position of the synthetic jet C hitting the wall and the relative distance L1 of the coolant can be optimized; by replacing the extension ring 4, the length of the thrust chamber, the size of the central recirculation zone and the distance L2 between the coolant film and the throat can be optimized. The scheme can be adjusted each time one or more parts are replaced.

[0052] like Figure 3 As shown, a first cooling circuit nozzle 17 and a second cooling circuit nozzle 18 are provided on the cooling ring 3, and the cooling circuit is supplied separately. The cooling ratio can be adjusted during the test run, and the appropriate cooling liquid film ratio can be determined by a single test run.

[0053] With the axis center of the thrust chamber body 6, the inner side wall of the cooling ring 3 is processed to have a first inclination angle of two different angles, γ and θ, with the radial plane of the body 6. In one test run, the effects of the two different angles γ and θ on the throat temperature can be verified simultaneously. γ and θ are different angle values ​​in the range of 70° to 90°. The throat temperature can be obtained by infrared temperature measurement.

[0054] With the axis center of the thrust chamber body 6, two groups of cooling holes are machined at one end of the cooling ring 3 close to the body 6, and the angle between the axis of the cooling hole and the radial plane of the body 6 is defined as the second inclination angle. A group of first cooling holes 19 with different cooling hole diameters and circumferential distances between the cooling holes and an inclination angle of α are opened on one side; a group of second cooling holes 20 with different cooling hole diameters and circumferential distances between the cooling holes and an inclination angle of β are opened on the other side. α and β are different angle values ​​within the range of 90° to 100°, the range of cooling hole diameters is 0.3mm to 2.0mm, and the range of circumferential distances between cooling holes is 5mm to 15mm. In a test run, the influence of different cooling hole angles on the throat temperature can be verified at the same time, and the cooling hole diameter and the circumferential distance between cooling holes can be adjusted at the same time to verify the influence of different cooling hole diameters and circumferential distances between cooling holes on the throat temperature.

[0055] The thrust chamber performance verification is performed using the modular thrust chamber verification structure for pintle injector optimization, which specifically includes the following steps:

[0056] Step 1, with the axis center of the thrust chamber body 6, the inner wall of the cooling ring 3 is processed into two angles of γ and θ; a group of first cooling holes 19 with different cooling hole diameters and different circumferential distances between the cooling holes and an inclination angle of α are opened on one side of the cooling ring 3 close to the body 6; a group of second cooling holes 20 with different cooling hole diameters and different circumferential distances between the cooling holes and an inclination angle of β are opened on the other side;

[0057] Step 2: Select the initial thickness adjustment ring 2 and extension ring 4, and connect the modular thrust chamber verification structure; set the initial flow of the cooling path, conduct the first test run verification, and measure, record and compare the throat temperatures of cooling holes with different inner wall angles of different cooling rings 3, cooling hole diameters, and circumferential distances between cooling holes through infrared temperature measurement;

[0058] Step 3: Keep the modular thrust chamber verification structure of step 2 unchanged, change the cooling path flow rate, and conduct test runs and verifications respectively. By measuring, recording and comparing the throat temperatures of cooling holes with different inner wall angles of the cooling ring 3, cooling hole diameters, and circumferential distances between cooling holes, the influence trend of different cooling path flow rates on the throat temperature is obtained.

[0059] Step 4: According to the influence trend of different cooling path flow rates on throat temperature obtained in step 3, the optimal cooling path flow rate and modular thrust chamber verification structure are selected, and the test run is performed again to measure the throat temperature and combustion efficiency at this time;

[0060] If the throat temperature and combustion efficiency meet the design requirements, the thrust chamber technical status is determined;

[0061] If the throat temperature or combustion efficiency does not meet the design requirements, proceed to step 5;

[0062] Step 5: Return to step 1 by replacing the adjustment ring 2 and the extension ring 4 with different thicknesses until the throat temperature and the combustion efficiency meet the design requirements.

[0063] Replacing the adjustment ring 2 can optimize the effects of the upper reflow zone size, the synthetic jet C wall impact position and the coolant relative distance L1 on the combustion efficiency and throat temperature;

[0064] Replacing the extension ring 4 can optimize the effects of the thrust chamber length, the center reflow zone size, and the distance L2 between the coolant film and the throat on the combustion efficiency and throat temperature;

[0065] If the throat temperature measured in step 4 is too high and the combustion efficiency is high, lengthen the adjustment ring 2 and reduce the extension ring 4, and the reduction value of the extension ring should be greater than the lengthening amount of the adjustment ring 2;

[0066] If the throat temperature measured in step 4 is high and the combustion efficiency is low, lengthen the adjustment ring 2 and reduce the extension ring 4, and the reduction value of the extension ring should be less than the lengthening amount of the adjustment ring 2;

[0067] If the throat temperature measured in step 4 is low and the combustion efficiency is low, the extension ring 4 and the adjustment ring 2 are lengthened.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein by equivalents. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A modular thrust chamber verification structure for pintle injector optimization, characterized in that: It comprises a pintle injector (1), an adjustment ring (2), a cooling ring (3), an extension ring (4) and a body (6) which are sealed and connected in sequence; The pintle injector (1), the adjustment ring (2) and the cooling ring (3) are connected by bolts; The cooling ring (3), the extension ring (4) and the body (6) are connected by bolts; With the axis center of the thrust chamber body (6), the included angle between the inner side wall of the cooling ring (3) and the radial plane of the body (6) is defined as a first inclination angle, and the inner side wall of the cooling ring (3) is provided with at least two different first inclination angles; At least two groups of cooling holes are machined at one end of the cooling ring (3) close to the body (6), and the angle between the axis of the cooling hole and the radial plane of the body (6) is defined as the second inclination angle. The diameters of the cooling holes, the circumferential distances between the cooling holes, and the second inclination angles of the cooling holes are all different.

2. The modular thrust chamber verification structure for pintle injector optimization according to claim 1, characterized in that: The inner side wall of the cooling ring (3) is provided with two first inclination angles of different angles, the first inclination angle on one side of the cooling ring (3) is γ, and the first inclination angle on the other side is θ; The cooling holes are in two groups, namely, first cooling holes (19) with a second inclination angle of α arranged at an end of one side of the cooling ring (3) close to the body (6), and second cooling holes (20) with a second inclination angle of β arranged at an end of the other side of the cooling ring (3) close to the body (6); The cooling ring (3) is provided with a first cooling passage nozzle (17) communicating with the first cooling hole (19) and a second cooling passage nozzle (18) communicating with the second cooling hole (20).

3. The modular thrust chamber verification structure for pintle injector optimization according to claim 2, characterized in that: The γ and θ are different angle values ​​within the range of 70° to 90°; The α and β are different angle values ​​within the range of 90° to 100°; The diameter of each cooling hole ranges from 0.3 mm to 2.0 mm; The circumferential distance between the cooling holes ranges from 5 mm to 15 mm.

4. The modular thrust chamber verification structure for pintle injector optimization according to any one of claims 1 to 3, characterized in that: The pintle injector (1) and the adjustment ring (2) and the adjustment ring (2) and the cooling ring (3) are sealed respectively by a first graphite sealing ring (7) and a second graphite sealing ring (8); The cooling ring (3) and the extension ring (4) as well as the extension ring (4) and the body 6 are sealed respectively by a third graphite sealing ring (9) and a fourth graphite sealing ring (10).

5. A modular thrust chamber verification method for pintle injector optimization, using the modular thrust chamber verification structure for pintle injector optimization as claimed in claim 1, characterized in that: The following steps are involved: Step 1, setting at least two different first inclination angles on the inner side wall of the cooling ring (3) with the axis center of the thrust chamber body (6); At least two groups of cooling holes having different cooling hole diameters, circumferential distances between the cooling holes, and second inclination angles are processed at one end of the cooling ring (3) close to the body (6); Step 2, select an adjustment ring (2) and an extension ring (4) of initial thickness, and connect the modular thrust chamber verification structure; set the initial flow rate of the cooling path, conduct the first test run verification, measure, record and compare the throat temperatures corresponding to the cooling holes with different inner wall angles, cooling hole diameters and circumferential distances between cooling holes of different cooling rings (3); Step 3, keeping the modular thrust chamber verification structure of step 2 unchanged, changing the cooling path flow rate, and conducting test runs and verifications respectively, and obtaining the influence trend of different cooling path flow rates on the throat temperature by measuring, recording and comparing the throat temperatures of cooling holes corresponding to different cooling ring (3) inner wall angles, cooling hole diameters, and circumferential distances between cooling holes through infrared temperature measurement; Step 4: According to the influence trend of different cooling path flow rates on throat temperature obtained in step 3, the optimal cooling path flow rate and modular thrust chamber verification structure are selected, and the test run is performed again to measure the throat temperature and combustion efficiency at this time; If the throat temperature and combustion efficiency meet the design requirements, the technical status of the thrust chamber is determined; If the throat temperature or combustion efficiency does not meet the design requirements, proceed to step 5; Step 5: Return to step 1 by replacing the adjustment ring (2) and the extension ring (4) of different thicknesses until the throat temperature and the combustion efficiency meet the design requirements.

6. The modular thrust chamber validation method for pintle injector optimization according to claim 5, characterized in that: In step 5, replace the adjustment ring (2) and extension ring (4) according to the following rules: a. If the throat temperature measured in step 4 is too high and the combustion efficiency is high, the adjustment ring (2) is lengthened and the extension ring (4) is shortened, and the shortening value of the extension ring should be greater than the lengthening amount of the adjustment ring (2); b. If the throat temperature measured in step 4 is high and the combustion efficiency is low, the adjustment ring (2) is lengthened and the extension ring (4) is shortened, and the shortening value of the extension ring should be less than the lengthening amount of the adjustment ring (2); c. If the throat temperature measured in step 4 is low and the combustion efficiency is low, lengthen the extension ring (4) and the adjustment ring (2).

7. The modular thrust chamber validation method for pintle injector optimization according to claim 6, characterized in that: The throat temperature is measured by infrared temperature measurement.

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