Gas piston driven operation fairing structure for high reynolds number hypersonic wind tunnel

Abstract

The present application belongs to the field of hypersonic wind tunnel equipment, and particularly relates to a gas piston driving operation rectifying structure for a high Reynolds number hypersonic wind tunnel. The gas piston driving operation rectifying structure comprises a flow equalizing tank at the bottom of a heater and in communication with a heater cylinder, the internal cavity of the flow equalizing tank is a flow equalizing cavity, the inner diameter of the flow equalizing cavity is greater than the inner diameter of the heater cylinder; the bottom surface of the flow equalizing tank is provided with a cold gas inlet, the top surface of the flow equalizing cavity is provided with a cold gas outlet, and the cold gas outlet is provided with a flow guide platform. The gas piston driving operation rectifying structure can maintain the constant temperature and pressure of the hot gas at the outlet of the heater without a solid piston; can fully utilize the super-high temperature and super-high pressure hot gas inside the heater without increasing the volume of the hot zone of the heater; can equalize and guide the entering super-high pressure cold gas flow through the flow equalizing cavity and the flow guide platform, avoid the cold gas center jet, improve the gas piston driving efficiency and the hot gas utilization rate, and prolong the effective operation time of the high Reynolds number hypersonic wind tunnel.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of hypersonic wind tunnel equipment, and particularly relates to a gas piston driving operation rectifying structure for a high Reynolds number hypersonic wind tunnel. BACKGROUND

[0002] The high Reynolds number hypersonic wind tunnel can simulate high Reynolds number and high Mach number simultaneously, the operation Mach number of which is far greater than 10, the highest total pressure of the airflow is 200 MPa, the highest total temperature of the airflow is 2300 K, and the wind tunnel Reynolds number is higher. Due to the high gas flow rate, the condensation of water vapor and carbon dioxide will occur when the airflow is rapidly expanded through the nozzle, which will cause the non-uniformity of the flow field and make the test data inaccurate. Therefore, a heater needs to be arranged in the hypersonic wind tunnel to heat the airflow to the required anti-condensation temperature. In order to meet the test airflow heating demand, the wind tunnel flow field index requirement and the high-precision aerodynamic force measurement demand, the heater needs to meet the following requirements: (1) the highest operation total pressure of the heater needs to reach 200 MPa, and the highest working temperature needs to reach 2300 K; (2) during the operation of the wind tunnel, the airflow temperature and pressure at the outlet of the heater need to remain unchanged, which are 2300 K and 200 MPa respectively; (3) the effective operation time of the wind tunnel needs to be greater than 1 second, that is, the volume of the super-high-temperature and super-high-pressure test airflow needs to be several cubic meters within the effective operation time; (4) the super-high-temperature and super-high-pressure test needs to be clean and pollution-free.

[0003] The direct heating type and the heat storage type electric heater used on the conventional hypersonic wind tunnel can provide stable test airflow for tens of seconds to meet the operation time requirement, but the working temperature is below 1373K and the maximum total pressure is below tens of megapascals, which cannot meet the heating temperature and the use pressure requirement of the test airflow of the high Reynolds number hypersonic wind tunnel. The shock wave wind tunnel or the detonation driving method can obtain the test airflow meeting the temperature and pressure requirement, but the super high temperature and super high pressure test airflow is maintained for a short time, about several milliseconds to several hundred milliseconds, and the impact load and the aerodynamic load in the starting process of the wind tunnel are difficult to distinguish, which leads to low precision of the aerodynamic data and cannot meet the operation requirement of the wind tunnel. Therefore, the electric heater is used to obtain the super high temperature and super high pressure test airflow of the high Reynolds number hypersonic wind tunnel, that is, the non-metallic heating element is used to directly heat the test airflow in the heater, and the heater outlet valve is opened after the test airflow is heated and pressurized to 2300K and 200MPa, so as to obtain the super high temperature and super high pressure test airflow. However, this method will cause the temperature and pressure of the airflow at the outlet of the heater to gradually decrease, which cannot meet the index requirement of the constant temperature and pressure of the wind tunnel inflow. To maintain the constant temperature and pressure of the airflow at the outlet of the heater, there are two common methods, one is to increase the volume of the heating zone of the heater by several times to ensure that the temperature and pressure decrease within the allowable range, but the manufacturing risk of the large-volume super high temperature and super high pressure container is extremely large. The other is to use a solid piston to push the hot gas in the heater to maintain the constant temperature and pressure of the airflow at the outlet of the heater, but the internal structure of the heater cannot be provided with a solid piston, and the driving of the solid piston is also difficult to realize.

[0004] In order to solve the problems of the short operation time of the shock wave wind tunnel or the detonation driving method, the gradual decrease of the temperature and pressure of the airflow at the outlet of the heater caused by the direct release of the hot gas, and the inability to set a solid piston, at present, it is urgent to develop a gas piston driving operation rectification structure for a high Reynolds number hypersonic wind tunnel. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a gas piston driving operation rectification structure for a high Reynolds number hypersonic wind tunnel, which solves the problems of the short operation time of the shock wave wind tunnel or the detonation driving method, the gradual decrease of the temperature and pressure of the airflow at the outlet of the heater caused by the direct release of the hot gas, and the inability to set a solid piston.

[0006] The gas piston driving operation rectification structure for a high Reynolds number hypersonic wind tunnel has the characteristics that the gas piston driving operation rectification structure comprises a flow equalizing tank located at the bottom of the heater and communicating with the cylinder body of the heater, the internal cavity of the flow equalizing tank is a flow equalizing cavity, and the inner diameter of the flow equalizing cavity is greater than the inner diameter of the cylinder body of the heater; the bottom surface of the flow equalizing tank is provided with a cold gas inlet, the top surface of the flow equalizing cavity is provided with a cold gas outlet, and a flow guide table is arranged at the cold gas outlet; the cold gas inlet, the flow equalizing cavity and the flow guide table are coaxial;

[0007] The flow guide platform is a rotary body, and sequentially comprises a head, a transition body, a flow guide plate, a tail and a baffle from bottom to top; the head is a cylindrical body I, the vertical distance between the lower end surface of the head and the bottom surface of the flow uniformizing cavity is H1, the annular flow passage area of the lower end surface of the head is larger than the flow passage area of the cold gas inlet; the transition body is a taper with a smaller diameter at the lower end and a larger diameter at the upper end; the flow guide plate is a circular ring horizontally extended outward from the top surface of the transition body, the outer diameter of the flow guide plate is larger than the diameter of the cold gas outlet and smaller than the inner diameter of the flow uniformizing cavity, the vertical distance between the upper surface of the flow guide plate and the top surface of the flow uniformizing cavity is h, h < H1, and the gap between the upper surface of the flow guide plate and the top surface of the flow uniformizing cavity forms an annular inlet channel; the tail is a cylindrical body II, the outer diameter of the tail is equal to the outer diameter of the top surface of the transition body; and the baffle is a tapered cylinder downward extended outward from the top surface of the tail, the taper angle of the baffle ranges from 30° to 60°.

[0008] Further, the heater cylinder has super-high-temperature and super-high-pressure hot gas, and the super-high-temperature and super-high-pressure hot gas is a gas with a maximum temperature of 2300K and a maximum pressure of 200MPa.

[0009] Further, the cold gas inlet is connected with super-high-pressure cold gas flow, and the super-high-pressure cold gas flow is a gas with a normal temperature of 323K and a pressure ranging from 200MPa to 250MPa.

[0010] The gas piston driving operation rectifying structure for the high Reynolds number hypersonic wind tunnel of the present application can make the super-high-pressure cold gas flow enter the flow uniformizing cavity through the cold gas inlet, and in the flow uniformizing cavity, the super-high-pressure cold gas flow is reduced in speed and is uniform in density and pressure; then, the super-high-pressure cold gas flow further reduces in speed and is guided to enter the bottom of the heater cylinder through the flow guide platform; because the cold gas has a large density and the hot gas has a small density, a cold-hot interface, i.e. a gas piston, is formed between the super-high-pressure cold gas flow and the super-high-temperature and super-high-pressure hot gas in the heater cylinder; with the continuous inflow of the cold gas and the continuous release of the hot gas, the cold-hot interface continuously moves to the top of the heater cylinder, i.e. the gas piston uniformly pushes and extrudes the super-high-temperature and super-high-pressure hot gas in the heater cylinder out of the heater, while keeping the hot gas temperature and pressure at the outlet of the heater constant; the hot gas temperature and pressure at the outlet of the heater can be kept constant for a long time without increasing the volume of the hot zone of the heater, the utilization rate of the super-high-temperature and super-high-pressure hot gas in the heater cylinder is improved, and the effective operation time of the high Reynolds number hypersonic wind tunnel is ensured to be 1 second to several tens of seconds.

[0011] The gas piston driving operation rectifying structure for the high Reynolds number hypersonic wind tunnel of the present application can keep the hot gas temperature and pressure at the outlet of the heater constant without a solid piston; the super-high-temperature and super-high-pressure hot gas in the heater can be fully utilized without increasing the volume of the hot zone of the heater; the super-high-pressure cold gas flow can be uniformly flowed and guided through the flow uniformizing cavity and the flow guide platform, the cold gas center jet is avoided, the gas piston driving efficiency and the hot gas utilization rate are improved, and the effective operation time of the high Reynolds number hypersonic wind tunnel is prolonged. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the gas piston-driven rectification structure for a high Reynolds number hypersonic wind tunnel according to the present invention;

[0013] Figure 2 This is a schematic diagram of the guide platform structure in the gas piston-driven rectification structure for a high Reynolds number hypersonic wind tunnel of the present invention.

[0014] Figure 3 The temperature field contour maps of the symmetry plane of the gas piston-driven rectification structure for high Reynolds number hypersonic wind tunnels of the present invention are shown at different times.

[0015] In the diagram, 1. Cold air inlet; 2. Flow equalization chamber; 3. Flow guide platform;

[0016] 301. Head; 302. Transition body; 303. Deflector; 304. Circumferential air intake; 305. Tail; 306. Baffle. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0018] Example 1

[0019] like Figure 1 As shown, the gas piston-driven rectification structure for a high Reynolds number hypersonic wind tunnel in this embodiment includes a flow equalization tank located at the bottom of the heater and connected to the heater cylinder. The internal cavity of the flow equalization tank is a flow equalization chamber 2, and the inner diameter of the flow equalization chamber 2 is larger than the inner diameter of the heater cylinder. A cold air inlet 1 is opened on the bottom surface of the flow equalization tank, and a cold air outlet is opened on the top surface of the flow equalization chamber 2. A guide platform 3 is provided at the cold air outlet. The cold air inlet 1, the flow equalization chamber 2, and the guide platform 3 are on the same central axis.

[0020] In this embodiment, the heater cylinder is covered with a non-metallic heating element, the heater cylinder contains ultra-high temperature and ultra-high pressure hot gas, the top of the heater cylinder has an ultra-high temperature and ultra-high pressure hot gas outlet, and the cold gas inlet 1 is filled with ultra-high pressure cold gas flow.

[0021] In this embodiment, the flow equalization cavity 2 plays a role in equalizing and slowing down the ultra-high pressure cold air flow entering from the cold air inlet 1;

[0022] like Figure 2 As shown, the flow guide platform 3 in this embodiment is a spiral body, consisting of a head 301, a transition body 302, a flow guide plate 303, a tail 305, and a baffle plate 306 from bottom to top.

[0023] The head 301 is a cylinder I, the vertical distance between the lower end surface of the head 301 and the bottom surface of the flow uniformizing cavity 2 is H1, the annular flow passage area of the lower end surface of the head is larger than the flow passage area of the cold gas inlet 1, the cold gas flow vertically upward can be introduced into the flow uniformizing cavity 2, the flow velocity is reduced, the central jet is avoided, and the flow velocity, density and pressure in the whole flow uniformizing cavity 2 are uniform;

[0024] The transition body 302 is a taper with a smaller diameter at the lower end and a larger diameter at the upper end, and the upper end of the transition body 302 is connected with the flow guide plate 303;

[0025] The flow guide plate 303 is a circular ring horizontally extending outward from the top surface of the transition body 302, the outer diameter of the flow guide plate 303 is larger than the diameter of the cold gas outlet and smaller than the inner diameter of the flow uniformizing cavity 2, the vertical distance between the upper surface of the flow guide plate 303 and the top surface of the flow uniformizing cavity 2 is h, and h < H1; the gap between the upper surface of the flow guide plate 303 and the top surface of the flow uniformizing cavity 2 forms an annular inlet channel 304, the cold gas flow can be uniformly introduced into the annular inlet channel 304 by the flow guide plate 303, the annular inlet channel 304 can further ensure that the cold gas flow entering the heater cylinder is uniform in velocity, density and pressure, and the flow velocity is low, thereby improving the driving efficiency of the gas piston;

[0026] The tail 305 is a cylinder II, the outer diameter of the tail 305 is equal to the outer diameter of the top surface of the transition body 302, and the tail 305 can further reduce the flow velocity of the cold gas flow, thereby reducing the mixing speed of the cold gas flow and the high-temperature and high-pressure hot gas, and improving the driving efficiency of the gas piston and the utilization rate of the hot gas;

[0027] The flow baffle 306 is a taper cylinder extending outward and downward from the top surface of the tail 305, has a baffle function, and the taper angle of the flow baffle 306 ranges from 30° to 60°; the flow baffle 306 can further reduce the upward flow velocity of the cold gas flow, change the flow direction of the cold gas flow, avoid the upward jet, ensure that the cold gas flow and the high-temperature and high-pressure hot gas form a relatively uniform interface, thereby reducing the mixing speed of the cold gas and the hot gas, and continuously improving the driving efficiency of the gas piston and the utilization rate of the hot gas.

[0028] The temperature field cloud images of the heater symmetry plane at different times obtained in the embodiment are shown in Figure 3 ; from Figure 3It can be seen that the gas piston driving operation rectifier structure for the high Reynolds number hypersonic wind tunnel of the embodiment can form the cold-hot interface, i.e. the gas piston, between the super-high pressure cold gas flow and the super-high temperature and super-high pressure hot gas in the heater cylinder. With the continuous inflow of the cold gas and the continuous release of the hot gas, the cold-hot interface continuously moves to the top of the heater cylinder, and the super-high temperature and super-high pressure hot gas in the heater cylinder is uniformly pushed out of the heater, while the hot gas temperature and pressure at the outlet of the heater are kept constant. The constant hot gas temperature and pressure at the outlet of the heater for a long time can be maintained without increasing the volume of the hot zone of the heater, the utilization rate of the super-high temperature and super-high pressure hot gas in the heater cylinder is improved, and the effective operation time of the high Reynolds number hypersonic wind tunnel is ensured to be 1 second to several tens of seconds.

[0029] Although the embodiments of the present application have been disclosed as above, they are not limited to the applications listed in the specification and the embodiments, and can be fully applied to various fields suitable for the present application. For those skilled in the art, other improvements and refinements can be easily realized without departing from the principles of the present application, and the present application is not limited to specific details and the figures shown and described herein.

Claims

1. A gas-piston-driven operating fairing structure for a high Reynolds number hypersonic wind tunnel, characterized by, The gas piston driving operation rectifier structure comprises a flow equalizing tank at the bottom of the heater and in communication with the heater cylinder, the internal cavity of the flow equalizing tank is a flow equalizing cavity (2), the inner diameter of the flow equalizing cavity (2) is larger than the inner diameter of the heater cylinder; the bottom surface of the flow equalizing tank is provided with a cold gas inlet (1), the top surface of the flow equalizing cavity (2) is provided with a cold gas outlet, and a flow guide table (3) is arranged at the cold gas outlet; the cold gas inlet (1), the flow equalizing cavity (2) and the flow guide table (3) are coaxial; The flow guide table (3) is a rotary body, and from bottom to top, it comprises a head (301), a transition body (302), a flow guide plate (303), a tail (305) and a flow blocking plate (306) in sequence; the head (301) is a cylindrical body I, the vertical distance between the lower end surface of the head (301) and the bottom surface of the flow equalizing cavity (2) is H1, and the circumferential flow area of the lower end surface of the head (301) is larger than that of the cold gas inlet (1); the transition body (302) is a taper with a smaller diameter at the lower end and a larger diameter at the upper end; the flow guide plate (303) is a circular ring horizontally extending outward from the top surface of the transition body (302), the outer diameter of the flow guide plate (303) is larger than the diameter of the cold gas outlet and smaller than the inner diameter of the flow equalizing cavity (2), the vertical distance between the upper surface of the flow guide plate (303) and the top surface of the flow equalizing cavity (2) is h, h < H1, and the gap between the upper surface of the flow guide plate (303) and the top surface of the flow equalizing cavity (2) forms a circumferential air inlet channel (304); the tail (305) is a cylindrical body II, and the outer diameter of the tail (305) is equal to the outer diameter of the top surface of the transition body (302); the flow blocking plate (306) is a tapered cylinder extending outward and downward from the top surface of the tail (305), and the taper angle of the flow blocking plate (306) ranges from 30° to 60°.

2. The gas-piston-driven operation fairing structure for a high Reynolds number hypersonic wind tunnel according to claim 1, characterized by, The heater cylinder has ultra-high temperature and ultra-high pressure hot gas, and the ultra-high temperature and ultra-high pressure hot gas is a gas with a maximum temperature of 2300K and a maximum pressure of 200MPa.

3. The gas-piston-driven operation fairing structure for a high Reynolds number hypersonic wind tunnel according to claim 1, characterized by, The cold gas inlet (1) is provided with an ultra-high pressure cold gas flow, and the ultra-high pressure cold gas flow is a gas with a normal temperature of 323K and a pressure ranging from 200MPa to 250MPa.

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