阅读说明：本技术 一种用于高焓条件下的亚声速包罩烧蚀试验装置 (Subsonic velocity envelope ablation test device used under high enthalpy condition ) 是由 刘雨翔 杨汝森 文鹏 欧东斌 张友华 于 2019-10-21 设计创作，主要内容包括：本发明公开一种用于高焓条件下的亚声速包罩烧蚀试验装置,包括包罩喷管、喉道支杆、转接法兰、转接段和模型支架。包罩喷管和模型支架固定于转接法兰上。喉道支杆经过转接段与模型支架连接,喉道支杆的喉道部分位于包罩喷管的内部。喉道支杆和转接段的连接保证与包罩喷管的中心轴线重合。试验进行时,试验模型安装在喉道支杆上,试验模型外表面与包罩喷管内表面之间的环形通道为高焓气流通道,气流在包罩喷管内的流动为亚声速流动。本发明可以应用于高焓气流状态下航空航天气动热防护地面模拟试验。(The invention discloses a subsonic velocity shroud ablation test device used under a high enthalpy condition, which comprises a shroud nozzle, a throat support rod, a switching flange, a switching section and a model bracket. The shrouding nozzle and the model support are fixed on the adapter flange. The throat branch is connected with the model bracket through the switching section, and the throat part of the throat branch is positioned inside the covering nozzle. The connection of the throat branch and the switching section ensures that the throat branch and the switching section are coincided with the central axis of the shroud nozzle. When the test is carried out, the test model is installed on the throat supporting rod, the annular channel between the outer surface of the test model and the inner surface of the shroud nozzle is a high-enthalpy airflow channel, and the airflow in the shroud nozzle flows in a subsonic speed mode. The invention can be applied to the aerospace aerodynamic thermal protection ground simulation test in the high enthalpy airflow state.)

1. The utility model provides a subsonic speed envelope ablation test device for under high enthalpy condition which characterized in that: comprises a covering spray pipe (1), a throat support rod (2), a switching flange (3), a switching section (4) and a model bracket (5);

the shrouding nozzle (1) and the model support (5) are fixed on the adapter flange (3), the throat support rod (2) is installed on the model support (5) through the adapter section (4), the central axes of the throat support rod (2), the adapter section (4) and the shrouding nozzle (1) are superposed, and the throat part of the throat support rod (2) is positioned in the shrouding nozzle (1);

when a test is carried out, the test model is arranged on the throat support rod (2), and an annular channel between the outer surface of the test model and the inner surface of the shroud nozzle (1) is a high-enthalpy airflow channel; after the heated and compressed high enthalpy air flows through the surface of the test model at subsonic velocity, the high enthalpy air reaches the sonic velocity at the throat of the throat support rod (2), and finally flows through the model support (5); in the test process, high-pressure water is introduced into the covering spray pipe (1), the throat support rod (2), the switching section (4) and the model bracket (5) for cooling.

2. The subsonic envelope ablation test apparatus for use in high enthalpy conditions according to claim 1, characterized in that: throat branch (2) include throat shell (21), model connecting block (22), connecting cylinder (23) and connecting rod (24), wherein:

the front end of the model connecting block (22) is used for installing a test model, the throat casing (21) is installed on the outer side of the model connecting block (22) and used for forming a sonic throat with the test nozzle, the connecting cylinder (23) and the connecting rod (24) are concentrically installed at the rear end of the model connecting block (22), and the connecting cylinder (23) is located on the outer side of the connecting rod (24) and is shorter than the connecting rod (24); the throat channel shell (21), the model connecting block (22), the connecting cylinder (23) and the connecting rod (24) are of an integrated water cooling structure; this integration water-cooling structure is including setting up the cooling water income water passageway in connecting rod (24) inside, this passageway and the catch basin intercommunication of setting in model connecting block (22), leave the gap between model connecting block (22) outside and throat shell (21) and set up annular water tank in the outside of model connecting block (22), this water tank both sides all set up the radial cooling water passageway of equipartition, wherein one side cooling water passageway with catch basin intercommunication, the clearance intercommunication between opposite side cooling water passageway and connecting cylinder (23) and connecting rod (24).

3. The subsonic envelope ablation test apparatus for use in high enthalpy conditions according to claim 2, characterized in that: the outlet of the cooling water channel communicated with the water storage tank is an inclined plane, and the included angle between the inclined plane and the axis of the rear end of the shaft of the connecting rod (24) ranges from 30 degrees to 60 degrees; the cross section area of a gap between the connecting cylinder (23) and the connecting rod (24) is larger than the minimum cross section area of a gap between the outer side of the model connecting block (22) and the throat casing (21); the radial sectional area of the annular water tank is not larger than that of the water storage tank, and the radial sectional area of the water storage tank is larger than that of a water inlet channel of the connecting rod (24).

4. The subsonic envelope ablation test apparatus for use in high enthalpy conditions according to claim 2, characterized in that: the throat casing (21) is supported by red copper materials, the appearance of the throat casing is a barrel-shaped structure with a flange, the flange structure is fixed on the model connecting block (22), the front edge of the flange and the corresponding position of the model connecting block (22) are positioned on the same plane and used for limiting the bottom of a test model arranged at the front end, and the connecting part of the inner side of the barrel-shaped structure and the flange structure is rounded and chamfered at the outer side; the diameter of the inner edge of the chamfer is not less than the minimum diameter of the base circle of all expected used test models, the diameter of the outer edge of the chamfer needs to ensure the throat area requirement at the position, and the chamfer angle is greater than the half cone angle of the test spray pipe; the throat casing (21) inclines outwards relative to the axis of the connecting rod (24), and the inclination angle is smaller than the half cone angle of the test nozzle; the throat casing (21), the model connecting block (22), the connecting cylinder (23) and the connecting rod (24) are integrated into a whole in a welding mode.

5. The subsonic envelope ablation test apparatus for use in high enthalpy conditions according to claim 1, characterized in that: the shrouded nozzle (1) comprises an inner shell (11), an outer shell (12) and a reinforcing rib group (13); wherein, the inner shell (11) and the outer shell (12) are hollow cone structures; the outer shell (12) is covered on the outer side of the outer wall of the inner shell (11); a cooling water inlet (121) is arranged on the outer wall of the small-diameter opening end of the shell (12) along the radial direction; a cooling water outlet (122) is arranged on the outer wall of the large-diameter opening end of the shell (12) along the radial direction; the outer wall of the inner shell (11) is fixedly connected with the two axial ends of the inner wall of the outer shell (12); a gap is reserved between the outer wall of the inner shell (11) and the inner wall of the outer shell (12); the reinforcing rib group (13) is arranged in a gap between the inner shell (11) and the outer shell (12); during an ablation experiment, the head end of the test model extends into the inner shell (11) from the large-diameter opening end of the inner shell (11); the external high enthalpy airflow flows in from the small diameter direction of the inner shell (11) and flows out from the large diameter direction of the inner shell (11); external cooling water enters a gap between the inner shell (11) and the outer shell (12) through a cooling water inlet (121) and flows out through a cooling water outlet (122);

the reinforcing rib group (13) comprises a long rib group (131) and a short rib group (132); the long rib group (131) and the short rib group (132) are arranged along the length direction of the side wall of the inner shell (11); the axial length of the long rib group (131) is the same as that of the side wall of the inner shell (11); one axial end of the long rib group (131) is positioned at the small-diameter end of the inner shell (11); the other axial end of the long rib group (131) is positioned at the large-diameter end of the inner shell (11); the axial length of the short rib group (132) is 170-180 mm; one axial end of the short rib group (132) is positioned at the large-diameter end of the inner shell (11);

the long rib group (131) comprises 24 long ribs; 24 long ribs are uniformly distributed on the outer wall of the inner shell (11) along the circumferential direction; the short rib group (132) comprises 24 short ribs; 24 short ribs are uniformly distributed on the outer wall of the inner shell (11) along the circumferential direction; and the long ribs and the short ribs are distributed in a staggered way.

6. The subsonic envelope ablation test apparatus for use in high enthalpy conditions according to claim 5, characterized in that: the inner shell (11) comprises a straight cylinder section (111), a first conical surface section (112), a second conical surface section (113), a third conical surface section (114) and a fourth conical surface section (115); the straight cylinder section (111), the first conical surface section (112), the second conical surface section (113), the third conical surface section (114) and the fourth conical surface section (115) are sequentially connected end to end along the axial direction to form an inner shell (11);

the half cone angle a of the first cone section (112) is 6.4 degrees; the half cone angle b of the second conical surface section (113) is 7.3 degrees; the half cone angle c of the third conical surface section (114) is 8.1 degrees; the half cone angle d of the fourth cone section (115) is 8.3 degrees, and the Mach number of the external high enthalpy flow between the external test model and the inner shell (11) is Ma0.6.

7. The subsonic envelope ablation test apparatus for use in high enthalpy conditions according to claim 5, characterized in that: the width of the long rib is kept unchanged along the length direction; the width of the rib is 2.8-3.2 mm; the high linearity of the long ribs along the length direction is reduced; the rib height of the long rib at the small-diameter end of the inner shell (11) is 8 mm; the rib height of the long rib at the large-diameter end of the inner shell (11) is 4.4 mm; after the external cooling water passes through the rib groups (3) between the inner shell (11) and the outer shell (12), the temperature rise of the external cooling water is less than 20 ℃ under the rated working condition.

8. The subsonic envelope ablation test apparatus for use in high enthalpy conditions according to claim 1, characterized in that: the model support (5) comprises a outsole flange (51), a supporting arm (52), a connecting flange (53) and a cooling water pipe (54); the outsole flange (51) is annular; the supporting arms (52) are L-shaped bent arms, one ends of the three supporting arms (52) are respectively and uniformly distributed along the circumferential direction of the outsole flange (51), and the other ends of the three supporting arms are close to the center to be connected with the central supporting piece, so that a three-arm supporting structure is formed; a cooling water channel is formed in the supporting arm (52) in a punching mode; the connecting flange (53) is positioned at one end of the central supporting piece and is positioned at the inner side of the three supporting arms (52); the cooling water pipes (54) are respectively coated on the periphery of each supporting arm;

the inlet of the cooling water channel in the supporting arm (52) is positioned on the outer side wall of one side of the supporting arm (52) along the axis, the outlet of the cooling water channel is positioned on the outer side wall of the other side of the supporting arm (52), and cooling water enters the cooling water channel from the outer sides of the three supporting arms (52) and flows out from the rear end of the supporting arm (52).

9. The subsonic envelope ablation test apparatus for use in high enthalpy conditions according to claim 8, characterized in that: the outsole flange (51), the supporting arm (52) and the connecting flange (53) are manufactured in an integral processing mode; the outsole flange (51), the supporting arm (52) and the connecting flange (53) are made of stainless steel, and the cooling water pipe (54) is made of red copper.

10. The subsonic envelope ablation test apparatus for use in high enthalpy conditions according to claim 8, characterized in that: the number of the cooling water pipes (54) is at least 3, and the support arms (52) are wound by using the cooling water pipes (54); the length of each cooling water pipe (54) is not more than 4 meters.

Technical Field

The invention relates to a subsonic velocity shroud ablation test device used under a high enthalpy condition, and belongs to the field of aerospace craft aerodynamic heat ground simulation test devices.

Technical Field

In a ground simulation test, the method for researching the ablation performance of the heat-proof material on the surface of the model by using the subsonic velocity envelope ablation test technology is a better technical approach. The method is mainly characterized in that high-temperature gas with limited energy can be limited on the surface of the model, so that the flight environment of a large-size test model can be simulated by the high-temperature gas with small mass flow.

Currently, with the establishment and the use of high-power high-enthalpy heating equipment, the development of an aircraft puts higher requirements on a pneumatic thermal ground simulation test. The existing ladle ablation test technology can only adapt to the test with the total enthalpy of airflow below 10MJ/kg, and can not meet the test requirement under the condition of higher total enthalpy of airflow. Therefore, a test device is brand-new designed by taking high-power high-enthalpy heating equipment as a support and closely surrounding the special test requirement of the large-size model subsonic velocity envelope under the high-enthalpy condition.

Disclosure of Invention

The technical problems to be solved by the invention are as follows: the problem that prior art exists is overcome, a subsonic velocity envelope ablation test device for under the high enthalpy condition is provided, in the subsonic velocity envelope ablation test under the high enthalpy condition, the temperature and the pressure of a test flow field are greatly improved compared with the current test condition, and it is required to ensure that the whole set of test equipment cannot break down or be damaged under the high enthalpy flow field environment.

The technical scheme of the invention is as follows:

a subsonic velocity shroud ablation test device used under a high enthalpy condition comprises a shroud nozzle, a throat support rod, a transfer flange, a transfer section and a model bracket;

the shrouding nozzle and the model bracket are fixed on the adapter flange, the throat support rod is arranged on the model bracket through the adapter section, the central axes of the throat support rod, the adapter section and the shrouding nozzle are superposed, and the throat part of the throat support rod is positioned inside the shrouding nozzle;

when the test is carried out, the test model is arranged on the throat branch, and an annular channel between the outer surface of the test model and the inner surface of the covering spray pipe is a high-enthalpy airflow channel; after the heated and compressed high enthalpy air flows through the surface of the test model at subsonic velocity, the high enthalpy air reaches the sonic velocity at the throat of the throat support rod and finally flows through the model support; in the test process, high-pressure water is introduced into the covering spray pipe, the throat support rod, the switching section and the model bracket for cooling.

Further, throat branch includes throat shell, model connecting block, connecting cylinder and connecting rod, wherein:

the front end of the model connecting block is used for installing a test model, the throat casing is arranged on the outer side of the model connecting block and used for forming a sonic throat with the test spray pipe, the connecting cylinder and the connecting rod are concentrically arranged at the rear end of the model connecting block, and the connecting cylinder is positioned on the outer side of the connecting rod and is shorter than the connecting rod; the throat casing, the model connecting block, the connecting cylinder and the connecting rod are of an integrated water cooling structure; this integration water-cooling structure is including setting up the cooling water passageway of intaking inside the connecting rod, this passageway and the catch basin intercommunication of setting in the model connecting block, leaves the gap and sets up annular basin in the outside of model connecting block between the model connecting block outside and the throat shell, this basin both sides all set up the radial cooling water passageway of equipartition, wherein one side cooling water passageway with catch basin intercommunication, the clearance intercommunication between opposite side cooling water passageway and connecting cylinder and the connecting rod.

Furthermore, the outlet of the cooling water channel communicated with the water storage tank is an inclined plane, and the included angle between the inclined plane and the axis of the rear end of the connecting rod shaft ranges from 30 degrees to 60 degrees; the sectional area of a gap between the connecting cylinder and the connecting rod is larger than the minimum sectional area of a gap between the outer side of the model connecting block and the outer shell of the throat; the radial sectional area of the annular water tank is not larger than that of the water storage tank, and the radial sectional area of the water storage tank is larger than that of the water inlet channel of the connecting rod.

Furthermore, the throat casing is supported by red copper materials, the appearance of the throat casing is a barrel-shaped structure with a flange, the flange structure is fixed on the model connecting block, the front edge of the flange is positioned on the same plane corresponding to the model connecting block and used for limiting the bottom of a test model arranged at the front end, and the connecting part of the inner side of the barrel-shaped structure and the flange structure is rounded and the outer side of the barrel-shaped structure is chamfered; the diameter of the inner edge of the chamfer is not less than the minimum diameter of the base circle of all expected used test models, the diameter of the outer edge of the chamfer needs to ensure the throat area requirement at the position, and the chamfer angle is greater than the half cone angle of the test spray pipe; the throat casing inclines outwards relative to the axis of the connecting rod, and the inclination angle is smaller than the half cone angle of the test nozzle; the throat casing, the model connecting block, the connecting cylinder and the connecting rod are integrated into a whole in a welding mode.

Furthermore, the shrouding nozzle comprises an inner shell, an outer shell and a reinforcing rib group; wherein, the inner shell and the outer shell are hollow cone structures; the outer shell is coated on the outer side of the outer wall of the inner shell; a cooling water inlet is arranged on the outer wall of the small-diameter opening end of the shell along the radial direction; the outer wall of the large-diameter opening end of the shell is provided with a cooling water outlet along the radial direction; the outer wall of the inner shell is fixedly connected with the two axial ends of the inner wall of the outer shell; a gap is reserved between the outer wall of the inner shell and the inner wall of the outer shell; the reinforcing rib group is arranged in a gap between the inner shell and the outer shell; during an ablation experiment, the head end of the test model extends into the inner shell from the large-diameter opening end of the inner shell; the external high enthalpy airflow flows in from the small diameter direction of the inner shell and flows out from the large diameter direction of the inner shell; external cooling water enters a gap between the inner shell and the outer shell through the cooling water inlet and flows out through the cooling water outlet;

the reinforcing rib group comprises a long rib group and a short rib group; the long rib groups and the short rib groups are arranged along the length direction of the side wall of the inner shell; the axial length of the long rib group is the same as that of the side wall of the inner shell; one axial end of the long rib group is positioned at the small-diameter end of the inner shell; the axial other end of the long rib group is positioned at the large-diameter end of the inner shell; the axial length of the short rib group is 170-180 mm; one axial end of the short rib group is positioned at the large-diameter end of the inner shell;

the long rib group comprises 24 long ribs; 24 long ribs are uniformly distributed on the outer wall of the inner shell along the circumferential direction; the short rib group comprises 24 short ribs; 24 short ribs are uniformly distributed on the outer wall of the inner shell along the circumferential direction; and the long ribs and the short ribs are distributed in a staggered way.

Further, the inner shell comprises a straight cylinder section, a first conical surface section, a second conical surface section, a third conical surface section and a fourth conical surface section; the straight cylinder section, the first conical surface section, the second conical surface section, the third conical surface section and the fourth conical surface section are sequentially connected end to end along the axial direction to form an inner shell;

the half cone angle a of the first conical surface section is 6.4 degrees; the half cone angle b of the second conical surface section is 7.3 degrees; the half cone angle c of the third conical surface section is 8.1 degrees; the half cone angle d of the fourth cone segment is 8.3 deg., and the mach number of the external high enthalpy flow between the external test model and the inner shell is ma0.6.

Further, the width of the long rib is kept unchanged along the length direction; the width of the rib is 2.8-3.2 mm; the high linearity of the long ribs along the length direction is reduced; the rib height of the long rib at the small-diameter end of the inner shell is 8 mm; the rib height of the long rib at the large-diameter end of the inner shell is 4.4 mm; after the external cooling water passes through the rib groups between the inner shell and the outer shell, the temperature rise of the external cooling water is less than 20 ℃ under the rated working condition.

Further, the model support comprises a large bottom flange, a supporting arm, a connecting flange and a cooling water pipe; the big bottom flange is annular; the supporting arms are L-shaped bent arms, one ends of the three supporting arms are uniformly distributed along the circumferential direction of the outsole flange, and the other ends of the three supporting arms are close to the center to be connected with the central supporting piece to form a three-arm supporting structure; a cooling water channel is formed in the supporting arm in a punching mode; the connecting flange is positioned at one end of the central supporting piece and is positioned at the inner sides of the three supporting arms; the cooling water pipes are respectively coated on the periphery of each supporting arm;

the inlet of the cooling water channel in the supporting arm is positioned on the outer side wall of one side of the supporting arm along the axis, the outlet of the cooling water channel is positioned on the outer side wall of the other side of the supporting arm, and cooling water enters the cooling water channel from the outer sides of the three supporting arms and flows out from the rear ends of the supporting arms.

Furthermore, the outsole flange, the supporting arm and the connecting flange are manufactured in an integral processing mode; the outsole flange, the supporting arm and the connecting flange are made of stainless steel, and the cooling water pipe is made of red copper.

Furthermore, the number of the cooling water pipes is at least 3, and a plurality of cooling water pipes are used for winding each supporting arm; the length of each cooling water pipe is not more than 4 meters.

The invention has the beneficial effects that:

(1) according to the invention, by using the subsonic mach number fixed nozzle, the integrated throat model support rod and the three-arm model supporting device, stable subsonic velocity high enthalpy airflow can be obtained, the uniform ablation of the surface of the model is ensured, and in addition, the burning loss of each test device by the high enthalpy airflow in the test process can be ensured, so that the safe test is ensured.

(2) The throat device and the model supporting device used in the current subsonic velocity shroud ablation test are mutually separated, the structure is complex, the heating surfaces of all the devices exposed in a high-enthalpy flow field environment are more, the structural form of the throat device can only adapt to the test of the total enthalpy of airflow below 10MJ/kg, and the throat device is easy to burn under the high-enthalpy test condition. According to the invention, the throat and the model connecting and supporting device are designed into a whole through an integrated design, so that the heating area can be effectively reduced, and the survival capability of the device is improved.

(2) The device is internally provided with an integrated water cooling structure, and through the design of a rationalized water cooling channel, the cooling effect of the device at the heated concentrated position is enhanced, the integral water flow resistance in the device is reduced, the device is cooled uniformly, and the required cooling water flow is reduced while the cooling efficiency is ensured.

(3) The throat casing is limited to be made of red copper material with high heat conductivity, so that the structural appearance can not be greatly changed under the condition of long-time high enthalpy airflow scouring, and the overall service life of the device is prolonged. The specific appearance design of the test model can enable high enthalpy airflow to form a sound velocity line with stable position only on the surface of the structure, so that the surface of the test model is ensured to be stable subsonic airflow, and the test can be effectively carried out.

(4) Through the design of the multi-section broken lines of the inner molded surface of the inner shell, the Mach number of the airflow on the surface of the model can be stably kept in a smaller floating range, so that a stable high-enthalpy flow field is obtained, on the other hand, the feedback error generated by unknown change of the outline size of the test model in the ablation process can be effectively reduced by a design method of taking +/-2% as an error limit and taking the minimum number of the broken lines, and the stability of the high-enthalpy flow field is ensured from the other aspect, so that the ablation uniformity of the surface of the model is ensured.

(5) The reinforcing rib is designed along the axial non-uniform, so that the sectional area of the cooling water channel is kept unchanged along the axial direction, the spray pipe has good cooling performance on the premise of ensuring the cooling effect of the reinforcing rib, and the safety of the spray pipe in the test process is ensured.

(6) Through the whole welding mode of inner shell and shell, can improve the spray tube pressure-bearing capacity on the one hand, ensure the security of spray tube in the test process, on the other hand can keep the stability and the homogeneity in high enthalpy flow field.

(7) The part of the model support in the test flow field is positioned at the lower part of the lower heat flow density, and the vulnerable parts of the inlet and the outlet of the cooling water channel, welding process holes formed in the machining and the like deviate from the test flow field; in addition, a large number of cooling water pipes surround the part of the device in the test flow field, and the device can be ensured to have sufficient reliability in a high-temperature flow field environment.

Drawings

FIG. 1 is a schematic view of a test apparatus of the present invention.

FIG. 2 is a schematic view of the flow of high enthalpy gas in the test apparatus of the present invention.

FIG. 3 is an axial cross-sectional view of an integrated throat model strut;

FIG. 4 is a schematic view of the flow of cooling water in the integrated throat model support rod;

FIG. 5 is a schematic view of the use of the integrated throat model strut;

FIG. 6 is a cross-sectional view of a Mach-number nozzle;

FIG. 7 is a schematic view of the distribution of long rib groups and short rib groups;

FIG. 8 is a schematic view of half cone angles of sections of the inner shell;

FIG. 9 is a schematic view of the structure of a model support;

FIG. 10 is a schematic view of the use of the mold support.

Detailed Description

The invention is described in detail with reference to the drawings and the detailed description.

The invention provides a subsonic velocity shroud ablation test device used under a high enthalpy condition, which comprises a shroud nozzle 1, a throat support rod 2, an adapter section 4 and a model support 5, as shown in figure 1. Wherein:

the shrouding nozzle 1 and the mould carrier 5 are fixed to the adapter flange 3. The throat branch rod 2 is installed on the model bracket 5 through the switching section 4, the connection of the throat branch rod 2 and the switching section 4 ensures that the throat branch rod coincides with the central axis of the shrouding nozzle 1, and the throat part of the throat branch rod 2 is positioned inside the shrouding nozzle 1.

Specifically, as shown in fig. 2, when the test is performed, the test model is mounted on the throat strut 2, and the annular channel between the outer surface of the test model and the inner surface of the shrouding nozzle 1 is a high enthalpy airflow channel. After the heated and compressed high enthalpy air flows through the surface of the test model at subsonic velocity, the high enthalpy air reaches the sonic velocity at the throat of the throat support rod 2 and finally flows through the model support 5. In the test process, high-pressure water is introduced into the covering spray pipe 1, the throat support rod 2, the switching section 4 and the model bracket 5 for cooling.

The Mach number fixed spray pipe solves the technical problems in advance that: 1. the inner molded surface of the spray pipe used in the current subsonic velocity shroud ablation test is designed to be a straight line along the axial direction, and the Mach number of the airflow on the surface of the model can jump, so that the flow field is unstable, and the ablation on the surface of the model is uneven; 2. the spray pipe used in the current subsonic velocity shroud ablation test can only be suitable for the ablation test with low total enthalpy of airflow, and under a high enthalpy airflow environment, the spray pipe is not uniformly cooled, and a local area is easy to burn out, so that cooling water leaks outwards, and the test fails; 3. the jet pipe pressure-bearing capacity that present subsonic speed envelope ablation test used is lower, uses rubber seal to seal between jet pipe outer shell and the inner shell. In the high enthalpy high pressure air current environment, the red copper inner shell produces great thermal strain easily for rubber seal inefficacy leads to the cooling water to leak outward, makes the experiment failure.

In the present invention, the shrouded nozzle 1 uses a subsonic mach number nozzle. The red copper inner shell and the stainless steel outer shell of the covered spray pipe are welded into a whole, so that the pressure bearing capacity of the spray pipe is improved, and the safety of the spray pipe in the test process is ensured; on the other hand, the inner profile of the spray pipe is of a multi-section broken line type, so that the stability and uniformity of a high-enthalpy flow field can be kept, and the accuracy of a test result is improved.

Specifically, the spray pipe comprises an inner shell 11, an outer shell 12 and a reinforcing rib group 13; preferably, the inner shell 11 may be made of a copper material. Since the red copper has excellent thermal conductivity, the cooling water can effectively cool the inner casing 11, preventing the inner casing 11 from being burnt by the high enthalpy airflow. Preferably, the housing 12 is made of stainless steel. The device can be used for multiple times without generating corrosion, and the service life of the device is prolonged. In addition, because red copper material intensity is lower, through welding into an organic whole between inner shell 11 and the shell 12, conduct the higher shell 12 of intensity with the pulling force that inner shell 11 received, can improve the spray tube pressure-bearing capacity on the one hand, ensure the security of spray tube in the test process, on the other hand can keep the stability and the homogeneity in high enthalpy flow field. Wherein, the inner shell 11 and the outer shell 12 are hollow cone structures; the outer shell 12 is coated outside the outer wall of the inner shell 11; the inner shell 11 and the outer shell 12 are integrally welded together. A cooling water inlet 121 is arranged on the outer wall of the small-diameter opening end of the shell 12 along the radial direction; the outer wall of the large-diameter opening end of the shell 12 is provided with a cooling water outlet 122 along the radial direction; the outer wall of the inner shell 11 is fixedly connected with the two axial ends of the inner wall of the outer shell 12; a gap is reserved between the outer wall of the inner shell 11 and the inner wall of the outer shell 12; the reinforcing rib group 13 is arranged in a gap between the inner shell 11 and the outer shell 12; during an ablation experiment, the head end of the external test model extends into the inner shell 11 from the large-diameter opening end of the inner shell 11; the external high enthalpy airflow flows in from the small diameter direction of the inner shell 11 and flows out from the large diameter direction of the inner shell 11; external cooling water enters a gap between the inner shell 11 and the outer shell 12 through the cooling water inlet 121 and flows out through the cooling water outlet 122; cooling of the lance is achieved as shown in figure 6.

As shown in fig. 7, the reinforcing bead group 13 includes a long bead group 131 and a short bead group 132; the long rib groups 131 and the short rib groups 132 are disposed along the length direction of the side wall of the inner case 11. The axial length of the long rib group 131 is the same as the length of the side wall of the inner shell 11; one axial end of the long rib group 131 is positioned at the small-diameter end of the inner shell 11; the other axial end of the long rib group 131 is positioned at the large-diameter end of the inner shell 11; the axial length of the short rib group 132 is 170-180 mm; and one axial end of the short rib group 132 is located at the large diameter end of the inner shell 11. The long rib group 131 includes 24 long ribs; 24 long ribs are uniformly distributed on the outer wall of the inner shell 11 along the circumferential direction; the short rib group 132 includes 24 short ribs; 24 short ribs are uniformly distributed on the outer wall of the inner shell 11 along the circumferential direction; and the long ribs and the short ribs are distributed in a staggered way. The width of the long rib is kept unchanged along the length direction; the width of the rib is 2.8-3.2 mm; the high linearity of the long ribs along the length direction is reduced; the rib height of the long rib at the small-diameter end of the inner shell 11 is 8 mm; the rib height of the long rib at the large-diameter end of the inner shell 11 is 4.4 mm. The design can keep the sectional area of the cooling water channel unchanged along the longitudinal direction on the premise of ensuring the cooling effect of the reinforcing rib, so that the spray pipe has good cooling performance, and the safety of the spray pipe in the test process is ensured;

during design, the area of a gap between an inner molded surface of the inner shell 11 and a test model is determined according to the size of the test model and the Mach number of a flow field, and the minimum number of broken line segments is limited by taking +/-2% as an error, the spray pipe uses four broken lines, and the inner shell 11 comprises a straight cylinder segment 111, a first conical surface segment 112, a second conical surface segment 113, a third conical surface segment 114 and a fourth conical surface segment 115; the straight section 111, the first conical section 112, the second conical section 113, the third conical section 114 and the fourth conical section 115 are sequentially connected end to end along the axial direction to form the inner shell 11. The half cone angle a of the first cone section 112 is 6.4 °; the half cone angle b of the second conical section 113 is 7.3 °; the half cone angle c of the third conical surface section 114 is 8.1 °; the half cone angle d of the fourth cone segment 115 is 8.3 deg., as shown in fig. 8. The structure enables the Mach number of the high-enthalpy high-pressure air flow between the outer surface of the test model and the inner profile of the inner shell 11 to be stably kept in a small floating range, and can also effectively reduce feedback errors generated by unknown changes of the outer dimension of the test model in the ablation process, so that a stable high-enthalpy flow field is obtained, and the ablation uniformity of the surface of the model is ensured.

The invention can be used for the subsonic velocity shroud ablation test, so that the model surface airflow Mach number can be stabilized in a smaller floating range in the test process, and the spray pipe can keep good cooling performance and pressure-bearing capacity in the test process, thereby improving the safety of the spray pipe and ensuring the uniform ablation of the model surface. The mach number of the external high enthalpy flow between the external test model and the inner shell 11 is ma0.6. After the external cooling water passes through the tendon groups 3 between the inner shell 11 and the outer shell 12, the temperature rise of the external cooling water is less than 20 ℃ under the rated working condition; and the consumed external cooling water amount is reduced by 25 percent compared with the traditional spray pipe. After the inner shell 11 and the outer shell 12 are matched through the reinforcing rib group 13, the inner wall and the outer wall of the inner shell 11 are in a limit pressure difference and temperature difference environment, the circumferential inner diameter thermal strain is reduced by 20%, and the axial thermal strain is reduced by 99%.

At present, with the establishment and the use of high-enthalpy and high-power electric arc heating equipment, a model development unit puts higher requirements on a pneumatic thermal ground simulation test. The throat structure form used in the existing subsonic velocity shroud ablation test can only adapt to the test with the total enthalpy of airflow below 10MJ/kg, and can not meet the test requirement under the condition of higher total enthalpy of airflow. In addition, the throat for the test is separated from the supporting structure of the model, so that the test device is complex in structure and easy to burn. Therefore, the throat and the model supporting device used in the test are newly designed around the special test requirement of the subsonic speed covering cover under the high enthalpy condition, the integration level of the device is increased, the heating area is reduced, and the survival capability of the device in the high enthalpy airflow state is improved.

The invention provides an integrated throat model support rod, which comprises a throat shell 21, a model connecting block 22, a connecting cylinder 23 and a connecting rod 24, as shown in figure 3, wherein:

the throat housing 21 is installed at the outside of the model connection block 22, the connection cylinder 23 and the connection rod 24 are concentrically installed at one end of the model connection block 22, and the connection cylinder 23 is located at the outside of the connection rod 24 and is shorter than the connection rod 24 for connecting the remaining fixing devices.

Specifically, as shown in fig. 4 and 5, in use, the test pattern is mounted on the other side of the model connection block 22. After entering from the distal end of the connecting rod 24, the cooling water reaches the bottom end of the mold connecting block 22 and spreads around, passes through the inside of the throat housing 21 to cool it, and finally flows out from the inside of the connecting cylinder 23. Through the integrated water-cooling structural design among the throat casing 21, the model connecting block 22, the connecting cylinder 23 and the connecting rod 24, the cooling effect of the device is enhanced, and the cooling water inlet and outlet ports are simplified, so that the survival capacity of the device is improved.

The form of an integrated water cooling structure is given below, including setting up the cooling water inlet channel inside the connecting rod, this passageway and the catch basin intercommunication of setting in the model connecting block, leave the gap between the model connecting block outside and the throat shell and set up annular water tank in the outside of model connecting block, this water tank both sides all set up the radial cooling water passageway of equipartition, wherein one side cooling water passageway with catch basin intercommunication, the clearance intercommunication between opposite side cooling water passageway and connecting cylinder and the connecting rod. The outlet of the cooling water channel communicated with the water storage tank is an inclined plane, and the included angle between the inclined plane and the axis of the rear end of the connecting rod shaft is 45 degrees. The sectional area of the gap between the connecting cylinder and the connecting rod is larger than the minimum sectional area of the gap between the outer side of the model connecting block and the outer shell of the throat channel. The radial sectional area of the annular water tank is not larger than that of the water storage tank, and the radial sectional area of the water storage tank is larger than that of the water inlet channel of the connecting rod.

As shown in fig. 3 and 5, the throat casing is supported by red copper material, the appearance is a barrel-shaped structure with a flange, the flange structure is fixed on the model connecting block, the flange front edge and the corresponding position of the model connecting block are positioned on the same plane and used for limiting and installing the bottom of the test model at the front end, and the connecting part of the inner side of the barrel-shaped structure and the flange structure is rounded and chamfered at the outer side. The diameter of the inner edge of the chamfer is not less than the minimum diameter of the base circle of all expected used test models, the diameter of the outer edge of the chamfer needs to ensure the throat area requirement at the position, and the chamfer angle is greater than the half cone angle of the test spray pipe. The throat shell inclines outwards relative to the axis of the connecting rod, and the inclination angle is smaller than the half cone angle of the test nozzle.

Adopt the welding mode integrated as an organic whole between throat shell 21, model connecting block 22, connecting cylinder 23 and the connecting rod 24, increase the device integration level, reduce heated area, improve the viability of device under high enthalpy air current state.

The throat support rod provided by the invention uses the integrated throat model support rod, so that on one hand, high enthalpy airflow can be ensured to reach the sound velocity at the downstream of the test model, and thus the airflow on the surface of the model keeps a subsonic velocity state; on the other hand, the structure appearance can be effectively reduced, the heating area is reduced, and the survival capacity of the device in high enthalpy airflow is improved.

The switching section 4 is used for converting throat struts 2 with different sizes and different interface forms into a uniform connection form and connecting the uniform connection form to a model bracket 5, and simultaneously guiding cooling water in the throat struts 2 to flow out in the downstream direction of a high enthalpy flow field.

The model support 5 proposed by the present invention, as shown in fig. 9, comprises a large bottom flange 51, a support arm 52, a connecting flange 53 and a cooling water pipe 54, wherein:

the big end flange 51 is the annular for connect experimental wind tunnel body or other equipment with, and support arm 52 is L shape curved boom, and the one end of three support arms 52 is followed big end flange 51 circumference evenly distributed, goes up to experimental flow field downstream direction and extends the certain distance and draw close central support piece to the center, forms three arm bearing structure, forms the cooling water passageway through the mode of punching in the support arm 52. The connecting flange 53 is located at one end of the central support member and located at the center where the three-arm support structure is closed, and is used for connecting test equipment such as a test model support rod. The cooling water pipes 54 are respectively tightly wrapped around the support arms 3.

Specifically, as shown in fig. 10, the method for using the three-arm model support device includes the following steps: the test pattern struts are mounted in the attachment flange 53. The outsole flange 51 is connected to a test wind tunnel body or other equipment. During testing, only the radial portion of the support arm 52 of the device is located within the test flow field, and the high temperature gas flow bypasses the radial portion of the support arm 52 and flows downstream after flowing over the test pattern surface. The cooling water enters the cooling water passage from the outer sides of the three support arms 52 and flows out from the rear ends of the support arms 52. The welding process holes on the cooling water channel are all positioned outside the supporting arm 52.

The large base flange 51, the support arms 52 and the connecting flange 53 of the device are manufactured using an integral process to ensure sufficient structural strength. The part of the device in the test flow field is positioned at the downstream with lower heat flow density, and the vulnerable parts of the inlet and the outlet of the cooling water channel, welding process holes formed in the machining and the like deviate from the test flow field, so that the device can be ensured to have enough reliability in the high-temperature flow field.

Preferably, the outsole flange 51, the supporting arm 52 and the connecting flange 53 of the device can be made of high-quality stainless steel, so that the device is prevented from being rusted after being used, and the service life of the device is prolonged.

Preferably, the cooling water pipe 54 in the device is made of red copper, and several water pipes can be wound to ensure that the cooling water pipe 54 can tightly cover the support arm 52 and make the internal cooling water have sufficient fluidity. Wherein the length of each cooling water pipe 54 is not more than 4 meters.

Preferably, a powerful electric arc heater can be connected upstream of the shrouding nozzle 1 as a device for generating high enthalpy gas. In a ground simulation test, the arc heating test equipment becomes the preferred heating equipment due to the advantages of real simulated gas components, wide parameter adjusting range, long-time heating and the like.

The description of the composition device and the experimental verification prove that the hypersonic speed enveloping ablation test device has the characteristics that the subsonic speed enveloping ablation test can be carried out under the condition of high enthalpy, the test can simulate the heated state of an aircraft, the test flow field state is stable, the ablation on the surface of a model is uniform, and high enthalpy airflow does not burn the support structure of the model in the test process. The present invention is not disclosed in the technical field of the common general knowledge of the technicians in this field.