A direct radiation-convection coupled aerodynamic-thermal ground simulation test device

Abstract

This invention relates to a direct-fire radiation-convection coupled aerodynamic thermal ground simulation test device, comprising a convection heat source, a four-way mixing chamber, a radiation heat source, an ellipsoidal reflector, a water-cooled nozzle, a test model, and a model loading base. Two convection heat sources are bolted together at both ends of the transverse passage of the airflow chamber in the four-way mixing chamber. One radiation heat source is threaded to the radiation source mounting hole in the four-way mixing chamber. The ellipsoidal reflector, after being coated with high thermal conductivity silicone grease, is attached to the radiation chamber of the four-way mixing chamber and secured by pressure between the radiation chamber and the airflow chamber. The water-cooled nozzle is bolted to the small end of the longitudinal passage of the airflow chamber in the four-way mixing chamber. The test model is mounted on the model loading base, with the model's stagnation point a certain distance from the water-cooled nozzle outlet and located at the far focal point of the ellipsoidal reflector. This invention is mainly used for radiation-convection coupled aerodynamic thermal ground simulation tests.

Description

Technical Field

[0001] This patent relates to a direct-fire radiation-convection coupled aerodynamic thermal ground simulation test device, belonging to the field of aerodynamic thermal ground simulation test devices for aerospace vehicles. Technical Background

[0002] The thermal protection design of reentry vehicles for lunar exploration and interplanetary return requires consideration of both convective and radiative heating, with the ratio of these two heating methods varying depending on the vehicle's speed and altitude. Ground-based simulation tests of thermal protection materials also necessitate the evaluation of these two heating methods. In vehicle thermal protection design, the primary mechanism of convective heating is the convective heat transfer effect caused by the direct impact of high-temperature airflow on the surface of the thermal protection material. The primary mechanism of radiative heating is the radiative heating of the thermal protection material after the dissociation and ionization of high-temperature gas. Radiation-convective coupled aerodynamic heating tests, as an important experimental method for the refined design of thermal protection structures for high-speed reentry vehicles, are gradually being implemented. In these tests, high-temperature airflow generated by devices such as electric arc heaters and gas flow is used as the convective heat source, while high-energy radiation generated by devices such as quartz lamps, carbon arc lamps, and xenon arc lamps is used as the radiative heat source. These heat sources act simultaneously on the surface of the test model to simulate the coupling effect of convective heating generated by the atmosphere and radiative heating generated by high-intensity shock waves on the thermal protection material during high-speed reentry.

[0003] In the aforementioned convective and radiative heat source generating devices, the electric arc heater or gas flow equipment used as the convective heat source is typically large and complex, while the radiative heat source usually has a simpler structure. Therefore, currently used radiative-convective coupled aerodynamic thermal experimental devices are all improvements on convective heat source devices. However, in traditional convective heating equipment and the test model are arranged on the same axis, meaning that the radiation generated by the radiative heat source in the improved radiative-convective coupled experimental device needs to be reflected or obliquely incident on the test model. This results in low radiative thermal efficiency and low radiation uniformity on the test model surface. To improve the aforementioned drawbacks of the radiative thermal environment in radiative-convective coupled experimental devices, a completely new experimental device needs to be developed. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a radiation-convection coupling test device that can generate a direct irradiation radiative thermal environment and a convective thermal environment with high flow field quality.

[0005] The technical solution of this invention: A direct-fire radiation-convection coupled aerodynamic thermal ground simulation test device, comprising a convective heat source, a four-way mixing chamber, a radiation heat source, an ellipsoidal reflector, a water-cooled nozzle, a test model, and a model delivery base; wherein:

[0006] The four-way mixing chamber includes an airflow chamber and a radiation chamber; the airflow chamber is a cross-shaped cavity formed by the intersection of a longitudinal cavity and a transverse cavity; the longitudinal cavity is conical, and the transverse cavity is cylindrical with small ends and a large middle; the radiation chamber is a semi-ellipsoidal inner cavity; the large end of the longitudinal cavity of the airflow chamber is connected to the large end of the semi-ellipsoidal inner cavity and their axes coincide.

[0007] There are two convective heat sources, connected to both ends of the transverse passage of the airflow cavity. There is one radiative heat source, installed on the outside of the small end of the inner cavity of the semi-ellipsoid. The back of the ellipsoidal reflector is coated with thermal conductive material and then attached to the inner cavity of the semi-ellipsoid and fixed. The water-cooled nozzle is connected to the small end of the longitudinal passage of the airflow cavity. The test model is installed on the model feeding base. The model stagnation point is a certain distance away from the water-cooled nozzle outlet and is located at the far focal point of the ellipsoidal reflector.

[0008] The central axes of the radiative heat source and the experimental model are collinear, and the central axes of the two convective heat sources are collinear and the two lines are orthogonal.

[0009] The rays emitted by the radiant heat source are reflected by the ellipsoidal reflector and gradually converge along the longitudinal axis of the device to the end face of the stationary point of the test model, forming a radiant heating field.

[0010] The high-pressure cold air introduced into the two convective heat sources is heated to become high-pressure hot air. It enters the airflow chamber of the four-way mixing chamber and mixes with the high-pressure cold air introduced into the airflow chamber and the radiation chamber. After being rectified through the longitudinal passage of the airflow chamber, it enters the water-cooled nozzle and is accelerated by the water-cooled nozzle before flowing over the surface of the test model to form a convective heating field.

[0011] Preferably, the airflow cavity includes a four-way inner shell, a first air inlet ring, a small-end flange, a four-way outer shell, an upstream flange, and a large-end flange; the outer wall of the four-way inner shell has a rib structure; the four-way outer shell wraps around the outside of the four-way inner shell, and the cavity formed between its inner wall and the ribs of the outer wall of the four-way inner shell is a first water-cooling channel; the small-end flange is installed on one side of the small end of the longitudinal cavity of the four-way inner shell, and the outer wall of the flange has a first water outlet channel, and the inner wall has an annular first water collection groove; the upstream flange is installed on both sides of the transverse cavity of the four-way inner shell, two in total, and the outer wall of the flange has a first water inlet channel, and the inner wall has an annular first water collection groove; the large-end flange is installed on one side of the large end of the longitudinal cavity of the four-way inner shell, and the outer wall of the flange has a first water outlet channel and a first air inlet channel, and the inner wall has an annular first water collection groove and a first air collection groove; the first air inlet ring is installed on the inner side of the first air collection groove of the large-end flange, and several first air inlet holes are evenly distributed on it;

[0012] The radiation cavity includes an inner shell, a second air inlet ring, a connecting flange, an outer shell, and a radiation flange. The outer wall of the inner shell has ribs, and an air-cooling channel is formed along the axis of symmetry at the apex of the ellipsoid. The outer shell wraps around the inner shell, and a second water-cooling channel is formed between its inner wall and the ribs on the outer wall of the inner shell. The connecting flange is installed at the large end of the inner shell, with a second water outlet channel on its circumferential outer wall and an annular second water collection groove on its inner wall. The radiation flange is installed at the small end of the inner shell, with a second water inlet channel and a second air inlet channel on its circumferential outer wall, and an annular second water collection groove and a second air collection groove on its inner wall. A radiation source mounting hole is formed along the axis of symmetry on the flange's end face near the second air collection groove. The second air inlet ring is installed inside the second air collection groove of the radiation flange, and several second air inlet holes are evenly distributed on it.

[0013] Preferably, the first intake ring is a circular ring of equal diameter, with the first intake hole on its outer circular surface having the same inlet direction as the radial direction, and the outlet direction on the inner circular surface of the first intake ring forming a 45° angle with the axis of the first intake ring, with a rounded transition between the two, and the radius of the transition rounded corner on the central axis of the first intake hole being not less than the thickness of the first intake ring; the sum of the cross-sectional areas of the first intake holes is equal to the sum of the cross-sectional areas of the first intake channels; the taper of the longitudinal cavity is consistent with the convergence path of the radiation source; and the inner surfaces of the longitudinal cavity and the transverse cavity are tangent at their intersection.

[0014] Preferably, the second air intake ring is tapered at 45° to the axis of the radiation cavity, and the second air intake holes distributed on it are perpendicular to the surface of the second air intake ring; the sum of the cross-sectional areas of the second air intake holes is equal to the sum of the cross-sectional areas of the second air intake channels; the number of the second air intake channels and the sum of their cross-sectional areas are respectively greater than the number of the first air intake channels and the sum of their cross-sectional areas.

[0015] Preferably, the ratio of the sum of the water resistance of the first water-cooling channel and the second water-cooling channel in the four-way mixing chamber to the total water resistance of the entire test device is less than 0.3.

[0016] Preferably, the gap width between the outer wall of the radiant heat source and the air-cooling channel of the four-way mixing chamber is not less than 2mm.

[0017] Preferably, the focal length of the ellipsoidal reflector is no greater than 1m, and the inner cavity of the semi-ellipsoid has the same shape as the outer wall surface of the ellipsoidal reflector.

[0018] Preferably, the inner wall of the water-cooled nozzle does not intersect with the radiation convergence area formed by the radiant heat source, and the length of the water-cooled nozzle should be such that the distance between its outlet and the stagnation point of the test model is less than 10 mm.

[0019] Preferably, the pressure of the high-pressure cold air introduced into the four-way mixing chamber is greater than the pressure of the high-pressure hot air inside the convection heat source after the convection heat source is started.

[0020] Preferably, the spherical radius or planar radius of the stagnation end face of the test model is not greater than 1.2 times the outlet radius of the water-cooled nozzle.

[0021] Preferably, the model is fed into the base at a speed greater than 1 m / s, with a control accuracy of less than 0.2 mm and a maximum thrust greater than 3 t.

[0022] A test method utilizing the aforementioned direct-type radiation-convection coupled aerodynamic-thermal ground simulation test device includes:

[0023] Before the test device is started, the model is sent into the base and the test model is moved to the outlet of the water-cooled nozzle; high-pressure cooling water is introduced into the two convection heat sources, the four-way mixing chamber and the water-cooled nozzle, and high-pressure cold air is introduced into the two convection heat sources and the four-way mixing chamber.

[0024] The test apparatus is activated, and the model is moved to the center of the water-cooled nozzle outlet by the control base. Radiation emitted from the heat source is reflected by the ellipsoidal reflector and gradually converges along the longitudinal axis of the apparatus at the stagnation point end face of the test model, forming a radiative heating field. At this time, high-pressure cooling water in the radiation cavity of the four-way mixing chamber is used to cool the ellipsoidal reflector, and high-pressure cold air is used to cool the heat source. The high-pressure cold air in the two convective heat sources is heated to become high-pressure hot air, which enters the airflow cavity of the four-way mixing chamber relative to each other, mixing with the high-pressure cold air flowing into both the airflow cavity and the radiation cavity. This mixture is then rectified through the longitudinal passage of the airflow cavity of the four-way mixing chamber and enters the water-cooled nozzle. After being accelerated by the water-cooled nozzle, it flows over the surface of the test model, forming a convective heating field. At this time, the high-pressure cooling water in the convective heat source, the airflow cavity of the four-way mixing chamber, and the water-cooled nozzle is used to cool their respective devices.

[0025] After the test, the model was moved to the base and controlled to move to the outlet of the water-cooled nozzle. The two convection heat sources, the airflow chamber of the four-way mixing chamber, and the water-cooled nozzle stopped receiving high-pressure cooling water and high-pressure cold air. The radiation chamber of the four-way mixing chamber continued to receive high-pressure cooling water and high-pressure cold air until the radiation heat source cooled to room temperature.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] (1) The present invention can provide a direct radiation heating field without reflection or oblique illumination, effectively improving the radiation heat efficiency and radiation uniformity of the receiving surface.

[0028] (2) The present invention can integrate two convective heat sources, effectively improve the total convective heat power, thereby expanding the size of the convective flow field and thus expanding the size of the test model;

[0029] (3) The present invention places two convective heat sources opposite each other. The high-pressure hot gas generated can be more effectively mixed and de-swirled with the high-pressure cold gas by colliding with each other in the four-way mixing chamber. After being rectified by the longitudinal cavity of the four-way mixing chamber, a flow field with higher uniformity is formed. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a direct-type radiation-convection coupled aerodynamic thermal ground simulation test device according to an embodiment of the present invention.

[0031] Figure 2(a) is a schematic diagram of the high-pressure cooling water flow path when used in an embodiment of the present invention;

[0032] Figure 2(b) is a schematic diagram of the high-pressure cold gas flow and the convection heating field and radiation heating field when used in the embodiment of the present invention;

[0033] Figure 3 This is a side sectional view of the four-way mixing chamber used in an embodiment of the present invention;

[0034] Figure 4 This is a cross-sectional view of the four-way mixing chamber airflow cavity used in an embodiment of the present invention;

[0035] Figure 5 This is a cross-sectional view of the four-way mixing chamber radiation cavity used in an embodiment of the present invention;

[0036] Figure 6 This is a schematic diagram illustrating the use of the four-way mixing chamber in an embodiment of the present invention. Detailed Implementation

[0037] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0038] This invention provides a direct-fire radiation-convection coupled aerodynamic thermal ground simulation test device, comprising a convection heat source 1, a four-way mixing chamber 2, a radiation heat source 3, an ellipsoidal reflector 4, a water-cooled nozzle 5, a test model 6, and a model delivery base 7, as shown. Figure 1 As shown. Wherein:

[0039] Two convective heat sources 1 are bolted together at both ends of the transverse passage of the airflow chamber in the four-way mixing chamber 2. One radiative heat source 3 is threaded to the radiative source mounting hole in the four-way mixing chamber 2. The back of the ellipsoidal reflector 4 is coated with high thermal conductivity silicone grease and then attached to the radiative cavity of the four-way mixing chamber 2. It is then pressed and fixed between the radiative cavity and the airflow chamber of the four-way mixing chamber 2. The water-cooled nozzle 5 is bolted to the small end of the longitudinal passage of the airflow chamber in the four-way mixing chamber 2. The test model 6 is mounted on the model feeding base 7. The model's stagnation point is a certain distance away from the outlet of the water-cooled nozzle 5 and is located at the far focal point of the ellipsoidal reflector 4.

[0040] Before starting the test setup, the model is placed into the base 7, and the test model 6 is moved to the outlet of the water-cooled nozzle 5. High-pressure cooling water is then introduced into the two convection heat sources 1, the four-way mixing chamber 2, and the water-cooled nozzle 5. Figure 2a As shown, high-pressure cold air is introduced into the two convection heat sources 1 and the four-way mixing chamber 2. After the device is started, as... Figure 2b As shown, the model is fed into the base 7, which controls the movement of the test model 6 to the outlet center of the water-cooled nozzle 5. The rays emitted by the radiant heat source 4 are reflected by the ellipsoidal reflector 4 and gradually converge along the longitudinal axis of the device to the stagnation point end face of the test model 5, forming a radiant heating field. At this time, the high-pressure cooling water in the radiation cavity of the four-way mixing chamber 2 is used to cool the ellipsoidal reflector 4, and the high-pressure cold air is used to cool the radiant heat source 3. The high-pressure cold air in the two convection heat sources 1 is heated to become high-pressure hot air, which enters the airflow cavity of the four-way mixing chamber 2 relative to each other, and mixes with the high-pressure cold air that flows into both the airflow cavity and the radiation cavity of the four-way mixing chamber 2. This mixture is then rectified through the longitudinal passage of the airflow cavity of the four-way mixing chamber 2 and enters the water-cooled nozzle 5. After being accelerated by the water-cooled nozzle 5, it flows over the surface of the test model 6, forming a convection heating field. At this time, the high-pressure cooling water in the convection heat source 1, the airflow cavity of the four-way mixing chamber 2, and the water-cooled nozzle 5 is used to cool their respective devices. After the test, the model is sent into the base 7 and the test model 6 is moved to the outlet of the water-cooled nozzle 5. The two convection heat sources 1, the airflow chamber of the four-way mixing chamber 2, and the water-cooled nozzle 5 stop supplying high-pressure cooling water and high-pressure cold air. The radiation chamber of the four-way mixing chamber 2 continues to supply high-pressure cooling water and high-pressure cold air until the radiation heat source 3 cools down to room temperature.

[0041] Specifically, the four-way mixing chamber 2 is a four-way mixing chamber for radiation-convection coupled aerodynamic heating experiments, including an airflow cavity 21 and a radiation cavity 22, such as... Figure 3 As shown. Wherein:

[0042] The airflow chamber 21 includes a small end flange 211, a four-way inner shell 212, a four-way outer shell 213, an upstream flange 214, a large end flange 215, and a first intake ring 216, as shown below. Figure 4As shown. The four-way inner shell 212 is a cross-shaped cylindrical structure formed by the intersection of a longitudinal cavity 2104 and a transverse cavity 2106. The longitudinal cavity 2104 is conical, and the transverse cavity 2106 is cylindrical with smaller ends and a larger middle. The outer wall of the four-way inner shell 212 has a ribbed structure. The four-way outer shell 213 wraps around the outside of the four-way inner shell 212, and the cavity formed between its inner wall and the ribs on the outer wall of the four-way inner shell 212 is the first water-cooling channel 2103. The small-end flange 211 is installed on one side of the small end of the longitudinal cavity 2104 of the four-way inner shell 212. The outer wall of the flange has a first water outlet channel 2101, and the inner wall has an annular first water collection groove 2102. Upstream flanges 214 are installed on both sides of the transverse cavity 2106 of the four-way inner shell 212, in total. The outer circumferential wall of the flange has a first water inlet channel 2105, and the inner wall has an annular first water collection groove 2102. Large-end flanges 215 are installed on one side of the longitudinal cavity 2104 of the four-way inner shell 212. The outer circumferential wall of the flange has a first water outlet channel 2101 and a first air inlet channel 2107, and the inner wall has an annular first water collection groove 2102 and a first air collection groove 2108. A first air inlet ring 216 is installed inside the first air collection groove 2108 of the large-end flange 215, and several first air inlet holes 2109 are evenly distributed on it.

[0043] The radiation cavity 22 includes a connecting flange 221, an inner shell 222, an outer shell 223, a radiation flange 224, and a second intake ring 225, as shown below. Figure 5 As shown. The inner shell 222 of the radiation cavity is a semi-ellipsoidal cavity 2204, with ribs on its outer wall. An air-cooling channel 2209 is formed along the axis of symmetry at the apex of the ellipsoid. The outer shell 223 of the radiation cavity wraps around the outer side of the inner shell 222, and a second water-cooling channel 2203 is formed between its inner wall and the ribs on the outer wall of the inner shell 222. A connecting flange 221 is installed at the large end of the inner shell 222, with a second water outlet channel 2201 on its circumferential outer wall and an annular second water collection groove 2202 on its inner wall. A radiation flange 224 is installed at the small end of the inner shell 222, with a second water inlet channel 2210 and a second air inlet channel 2205 on its circumferential outer wall, and an annular second water collection groove 2202 and a second air collection groove 2206 on its inner wall. A radiation source mounting hole 2208 is formed along the axis of symmetry on the end face of the flange near the second air collection groove 2206. The second air intake ring 225 is installed inside the second air collection groove 2206 of the radial flange 224, and several second air intake holes 2207 are evenly distributed on it.

[0044] like Figure 6As shown, in use, the airflow chamber 21 and the radiation chamber 22 are connected together by bolts through the large end flange 215 and the connecting flange 221, and high-pressure cooling water and high-pressure cold air are respectively introduced into the airflow chamber 21 and the radiation chamber 22. For the airflow chamber 21, the high-pressure cooling water enters the first water cooling channel 2103 from the first water inlet channel 2105 of the two upstream flanges 214, passes through the first water collection tank 2102, and merges at the intersection of the longitudinal passage 2104 and the transverse passage 2106, and then flows out from the first water outlet channel 2101 of the small end flange 211 and the large end flange 215 respectively. The high-pressure cold air enters the first air collection tank 2108 from the first air inlet channel 2107 of the large end flange 215, and then enters the four-way inner shell 212 from several first air inlet holes 2109 of the first air inlet ring 216. For the radiant cavity 22, high-pressure cooling water enters the second water cooling channel 2203 from the second water inlet channel 2210 of the radiant flange 224 through the second water collection tank 2202, and then flows out from the second water outlet channel 2201 of the connecting flange 221. High-pressure cold air enters the second air collection tank 2206 from the second air inlet channel 2205 of the radiant flange 224, flows through several second air inlet holes 2207 of the second air inlet ring 225, and enters the inner shell 222 of the radiant cavity through the air cooling channel 2209.

[0045] Specifically, the first intake ring 216 of the airflow cavity 21 is a circular ring of equal diameter. The first intake hole 2109 on the first intake ring 216 has its inlet direction in the same direction as the radial direction on the outer circular surface of the first intake ring 216, and its outlet direction on the inner circular surface of the first intake ring 216 forms a 45° angle with the axis of the first intake ring 216. There is a rounded transition between the two, and the radius of the transition rounded corner on the central axis of the first intake hole 2109 is not less than the thickness of the first intake ring 216. The second intake ring 225 of the radiation cavity 22 is tapered at a 45° angle to the axis of the radiation cavity 22, and the second intake holes 2207 distributed on it are perpendicular to the surface of the second intake ring 225.

[0046] Specifically, the sum of the cross-sectional areas of the first air inlets 2109 of the airflow cavity 21 is equal to the sum of the cross-sectional areas of the first air inlet channels 2107. The sum of the cross-sectional areas of the second air inlets 2207 of the radiation cavity 22 is equal to the sum of the cross-sectional areas of the second air inlet channels 2205.

[0047] Specifically, the sum of the number and cross-sectional area of ​​the second air intake channel 2205 is greater than the sum of the number and cross-sectional area of ​​the first air intake channel 2107.

[0048] Specifically, the taper of the longitudinal cavity 2104 of the airflow cavity 21 is consistent with the convergence path of the radiation source. The inner surfaces of the longitudinal cavity 2104 and the transverse cavity 2106 are tangent at their intersection.

[0049] Specifically, the semi-ellipsoidal inner cavity 2204 of the inner shell 222 of the radiation cavity 22 has the same shape as the outer wall of the ellipsoidal reflector 4 used by the radiation source.

[0050] Specifically, the four-way inner shell 212 and the radiation cavity inner shell 222 are made of zirconium bronze, while the remaining parts are made of stainless steel. All parts of the airflow cavity 21 and the radiation cavity 22 are assembled by vacuum furnace brazing.

[0051] Specifically, the central axes of the radiant heat source 3 and the experimental model 6 are collinear, and the central axes of the two convective heat sources 1 are collinear and orthogonal. The gap width between the outer wall of the radiant heat source 3 and the air-cooling channel 2209 of the four-way mixing chamber 2 is not less than 2mm.

[0052] Specifically, the focal length of the ellipsoidal reflector 4 is less than 1m.

[0053] Specifically, the inner wall of the water-cooled nozzle 5 does not intersect with the radiation convergence area formed by the radiant heat source 2. The length of the water-cooled nozzle 5 should ensure that the distance between its outlet and the stagnation point of the test model 6 is less than 10 mm.

[0054] Specifically, the pressure of the high-pressure cold air introduced into the four-way mixing chamber 2 is greater than the pressure of the high-pressure hot air inside the convection heat source 1 after it is started.

[0055] Specifically, the spherical or planar radius of the stagnation point end face of test model 6 is no greater than 1.2 times the outlet radius of water-cooled nozzle 5.

[0056] Specifically, the ratio of the sum of the water resistance of the first water-cooling channel 2103 and the second water-cooling channel 2203 in the four-way mixing chamber 2 to the total water resistance of the entire test device is less than 0.3.

[0057] Specifically, the model is fed into the base 7 at a speed greater than 1 m / s, with a control accuracy of less than 0.2 mm and a maximum thrust greater than 3 t.

[0058] The description of the constituent devices and experimental verification of the present invention have demonstrated the characteristics of the present invention. The radiative heat source collinear with the test model can provide a direct radiative heating field without reflection or oblique illumination, effectively improving the radiative heat efficiency and the radiation uniformity of the receiving surface. The two convective heat sources placed opposite each other can effectively increase the total convective heat power, thereby expanding the size of the convective flow field and thus expanding the size of the test model. Furthermore, the high-pressure hot gas generated can be more effectively mixed and de-swirled with the high-pressure cold gas by relative collision in the four-way mixing chamber. After rectification by the longitudinal cavity of the four-way mixing chamber, a flow field with higher uniformity is formed.

[0059] This invention can be applied to radiation-convection coupled aerodynamic thermal ground tests, and the undisclosed technologies are common knowledge to those skilled in the art. Although the invention has been disclosed above with preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make possible variations and modifications to the technical solutions of this invention using the disclosed methods and techniques without departing from the spirit and scope of the invention. Therefore, any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this invention, without departing from the content of the technical solutions of this invention, shall fall within the protection scope of this invention.

Claims

1. A direct-fire radiation-convection coupled aerodynamic-thermal ground simulation test device, characterized in that... Includes a convective heat source, a four-way mixing chamber, a radiative heat source, an ellipsoidal reflector, a water-cooled nozzle, a test model, and a model delivery base; among which: The four-way mixing chamber includes an airflow chamber and a radiation chamber; the airflow chamber is a cross-shaped cavity formed by the intersection of a longitudinal cavity and a transverse cavity; the longitudinal cavity is conical, and the transverse cavity is cylindrical with small ends and a large middle; the radiation chamber is a semi-ellipsoidal inner cavity; the large end of the longitudinal cavity of the airflow chamber is connected to the large end of the semi-ellipsoidal inner cavity and their axes coincide. There are two convective heat sources, connected to both ends of the transverse passage of the airflow cavity. There is one radiative heat source, installed on the outside of the small end of the inner cavity of the semi-ellipsoid. The back of the ellipsoidal reflector is coated with thermal conductive material and then attached to the inner cavity of the semi-ellipsoid and fixed. The water-cooled nozzle is connected to the small end of the longitudinal passage of the airflow cavity. The test model is installed on the model feeding base. The model stagnation point is a certain distance away from the water-cooled nozzle outlet and is located at the far focal point of the ellipsoidal reflector. The central axes of the radiative heat source and the experimental model are collinear, and the central axes of the two convective heat sources are collinear and the two lines are orthogonal. The rays emitted by the radiant heat source are reflected by the ellipsoidal reflector and gradually converge along the longitudinal axis of the device to the end face of the stationary point of the test model, forming a radiant heating field. The high-pressure cold air introduced into the two convective heat sources is heated to become high-pressure hot air. It enters the airflow chamber of the four-way mixing chamber and mixes with the high-pressure cold air introduced into the airflow chamber and the radiation chamber. After being rectified through the longitudinal passage of the airflow chamber, it enters the water-cooled nozzle and is accelerated by the water-cooled nozzle before flowing over the surface of the test model to form a convective heating field.

2. The direct-fire radiation-convection coupled aerodynamic-thermal ground simulation test device according to claim 1, characterized in that: The airflow cavity includes a four-way inner shell, a first air inlet ring, a small-end flange, a four-way outer shell, an upstream flange, and a large-end flange. The outer wall of the four-way inner shell has a rib structure. The four-way outer shell wraps around the outside of the four-way inner shell, and the cavity formed between its inner wall and the ribs on the outer wall of the four-way inner shell is the first water-cooling channel. The small-end flange is installed on one side of the small end of the longitudinal cavity of the four-way inner shell. The outer wall of the flange has a first water outlet channel, and the inner wall has an annular first water collection groove. The upstream flange is installed on both sides of the transverse cavity of the four-way inner shell, and there are two of them. The outer wall of the flange has a first water inlet channel, and the inner wall has an annular first water collection groove. The large-end flange is installed on one side of the large end of the longitudinal cavity of the four-way inner shell. The outer wall of the flange has a first water outlet channel and a first air inlet channel, and the inner wall has an annular first water collection groove and a first air collection groove. The first air inlet ring is installed on the inner side of the first air collection groove of the large-end flange, and several first air inlet holes are evenly distributed on it. The radiation cavity includes an inner shell, a second air inlet ring, a connecting flange, an outer shell, and a radiation flange. The outer wall of the inner shell has ribs, and an air-cooling channel is formed along the axis of symmetry at the apex of the ellipsoid. The outer shell wraps around the inner shell, and a second water-cooling channel is formed between its inner wall and the ribs on the outer wall of the inner shell. The connecting flange is installed at the large end of the inner shell, with a second water outlet channel on its circumferential outer wall and an annular second water collection groove on its inner wall. The radiation flange is installed at the small end of the inner shell, with a second water inlet channel and a second air inlet channel on its circumferential outer wall, and an annular second water collection groove and a second air collection groove on its inner wall. A radiation source mounting hole is formed along the axis of symmetry on the flange's end face near the second air collection groove. The second air inlet ring is installed inside the second air collection groove of the radiation flange, and several second air inlet holes are evenly distributed on it.

3. The direct-fire radiation-convection coupled aerodynamic thermal ground simulation test device according to claim 2, characterized in that: The first intake ring is a circular ring of equal diameter. The first intake hole on the outer circular surface of the first intake ring has the same inlet direction as the radial direction, and the outlet direction on the inner circular surface of the first intake ring forms a 45° angle with the axis of the first intake ring. There is a rounded transition between the two, and the radius of the transition rounded corner on the central axis of the first intake hole is not less than the thickness of the first intake ring. The sum of the cross-sectional areas of the first intake holes is equal to the sum of the cross-sectional areas of the first intake channels. The taper of the longitudinal cavity is consistent with the convergence path of the radiation source. The inner surfaces of the longitudinal cavity and the transverse cavity are tangent at the junction.

4. The direct-fire radiation-convection coupled aerodynamic thermal ground simulation test device according to claim 2, characterized in that: The second intake ring is tapered at 45° to the axis of the radiation cavity, and the second intake holes distributed on it are perpendicular to the surface of the second intake ring; the sum of the cross-sectional areas of the second intake holes is equal to the sum of the cross-sectional areas of the second intake channels; the number of the second intake channels and the sum of their cross-sectional areas are both greater than the number of the first intake channels and the sum of their cross-sectional areas.

5. A direct-fire radiation-convection coupled aerodynamic thermal ground simulation test device according to claim 2, characterized in that: The ratio of the sum of the water resistance of the first and second water-cooling channels in the four-way mixing chamber to the total water resistance of the entire test device is less than 0.

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6. The direct-fire radiation-convection coupled aerodynamic-thermal ground simulation test device according to claim 1, characterized in that: The gap width between the outer wall of the radiant heat source and the air-cooling channel of the four-way mixing chamber shall not be less than 2 mm.

7. The direct-fire radiation-convection coupled aerodynamic thermal ground simulation test device according to claim 1, characterized in that: The focal length of the ellipsoidal reflector is no greater than 1m, and the inner cavity of the semi-ellipsoid has the same shape as the outer wall of the ellipsoidal reflector.

8. The direct-fire radiation-convection coupled aerodynamic thermal ground simulation test device according to claim 1, characterized in that: The inner wall of the water-cooled nozzle does not intersect with the radiation convergence area formed by the radiant heat source, and the length of the water-cooled nozzle should be such that the distance between its outlet and the stagnation point of the test model is less than 10 mm.

9. A direct-fire radiation-convection coupled aerodynamic-thermal ground simulation test device according to claim 1, characterized in that: The pressure of the high-pressure cold air introduced into the four-way mixing chamber is greater than the pressure of the high-pressure hot air inside the convection heat source after the convection heat source is started.

10. A direct-fire radiation-convection coupled aerodynamic-thermal ground simulation test device according to claim 1, characterized in that: The spherical or planar radius of the stagnation point end face of the test model is no greater than 1.2 times the outlet radius of the water-cooled nozzle.

11. A direct-fire radiation-convection coupled aerodynamic-thermal ground simulation test device according to claim 1, characterized in that: The model is fed into the base at a speed greater than 1 m / s, with a control accuracy of less than 0.2 mm and a maximum thrust greater than 3 t.

12. A test method using the direct-fired radiation-convection coupled aerodynamic-thermal ground simulation test device as described in claim 1, characterized in that... include: Before the test device is started, the model is sent into the base and the test model is moved to the outlet of the water-cooled nozzle. High-pressure cooling water is introduced into the two convection heat sources, the four-way mixing chamber, and the water-cooled nozzles, and high-pressure cold air is introduced into the two convection heat sources and the four-way mixing chamber. The test apparatus is activated, and the model is moved to the center of the water-cooled nozzle outlet by the control base. Radiation emitted from the heat source is reflected by the ellipsoidal reflector and gradually converges along the longitudinal axis of the apparatus at the stagnation point end face of the test model, forming a radiative heating field. At this time, high-pressure cooling water in the radiation cavity of the four-way mixing chamber is used to cool the ellipsoidal reflector, and high-pressure cold air is used to cool the heat source. The high-pressure cold air in the two convective heat sources is heated to become high-pressure hot air, which enters the airflow cavity of the four-way mixing chamber relative to each other, mixing with the high-pressure cold air flowing into both the airflow cavity and the radiation cavity. This mixture is then rectified through the longitudinal passage of the airflow cavity of the four-way mixing chamber and enters the water-cooled nozzle. After being accelerated by the water-cooled nozzle, it flows over the surface of the test model, forming a convective heating field. At this time, the high-pressure cooling water in the convective heat source, the airflow cavity of the four-way mixing chamber, and the water-cooled nozzle is used to cool their respective devices. After the test, the model was moved to the base and controlled to move to the outlet of the water-cooled nozzle. The two convection heat sources, the airflow chamber of the four-way mixing chamber, and the water-cooled nozzle stopped receiving high-pressure cooling water and high-pressure cold air. The radiation chamber of the four-way mixing chamber continued to receive high-pressure cooling water and high-pressure cold air until the radiation heat source cooled to room temperature.

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