Heat and drag reduction system based on combined flow control of rough elements and micro jets and its application

Abstract

The present invention discloses a heat reduction and drag reduction system based on combined flow control of rough elements and microjets and its application. The system includes a high-temperature resistant skin, a rough element array, a microporous array, an air interface, an air supply pipeline, an air storage tank, an electromagnetic pressure reducing valve, a temperature sensor, a pressure sensor and a controller. The rough element array is arranged on the surface of the high-temperature resistant skin, and can achieve efficient drag reduction by regulating the boundary layer flow structure. When the rough element array is continuously eroded by high-temperature and high-speed incoming flow and the temperature rises to a level close to the upper limit of the safe operating temperature, the microjet system is turned on to enable the microporous array to generate a large number of microjets. On the one hand, heat reduction and drag reduction can be achieved by regulating the boundary layer flow structure, and on the other hand, a layer of low-temperature air film can be formed near the wall to protect the rough element array. The present invention simultaneously solves the thermal failure problem of the rough element technology and the cooling medium consumption problem of the microjet technology, and can achieve low-cost and high-reliability heat reduction and drag reduction effects, and has good engineering application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of flow control and heat and drag reduction of aerospace high-speed aircraft, and in particular to a high-speed aircraft heat and drag reduction system based on combined flow control of rough elements and microjets and an application method thereof. Background Art

[0002] Repeatable and efficient flight is a key development trend for hypersonic vehicles. To achieve this, there is an urgent need to develop efficient heat and drag reduction technologies to overcome the lift-to-drag ratio and thermal barriers. Due to volumetric limitations, existing aerodynamic layout design and optimization methods for hypersonic vehicles are unable to meet overall design requirements.

[0003] Rough element array technology, modeled after the scales on shark skin, can effectively improve near-wall flow structures, thereby achieving superior drag reduction. Because it requires no additional energy, rough element array technology is highly cost-effective and has been applied in various engineering fields. However, for hypersonic vehicles, the aerodynamic heating and scouring effects of high-temperature, high-speed incoming flow can easily damage the rough element array structure, leading to drag reduction failure.

[0004] An active flow control scheme that injects microjets into the boundary layer to form a wall-attached air film can effectively isolate the aerodynamic heating effects of external high-temperature, high-speed incoming flow on the aircraft wall, while also significantly improving the velocity gradient near the wall, thereby achieving excellent combined heat and drag reduction performance. However, microjet technology requires the continuous consumption of cooling fluid. For long-term flight missions, the load and volume costs of the cooling fluid and auxiliary equipment such as gas cylinders and valves can have a significant impact on the aircraft. Therefore, how to reduce the consumption of cooling fluid is an important research direction of microjet technology.

[0005] In summary, flow control heat reduction and drag reduction faces the contradiction between use cost and operational reliability. There is an urgent need to develop a comprehensive flow control heat reduction and drag reduction solution that can balance low cost and high reliability. Summary of the Invention

[0006] In order to solve the thermal failure problems of rough element technology and the cooling fluid consumption problems of microjet technology, the present invention proposes a heat reduction and drag reduction system and application based on the combined flow control of rough elements and microjets. On the one hand, it can ensure the safe and stable operation of the rough element array, and on the other hand, it can significantly reduce the cooling fluid consumption of the microjet technology, thereby achieving low-cost and high-reliability heat reduction and drag reduction effects.

[0007] The technical solutions of the present invention are as follows:

[0008] A high-speed aircraft heat reduction and drag reduction system based on combined flow control of rough elements and microjets includes a high-temperature resistant skin, a rough element array, a micropore array, an air path interface, an air supply pipeline, an air storage tank, an electromagnetic pressure reducing valve, a temperature sensor, a pressure sensor and a controller.

[0009] The high temperature resistant skin is made of alloy material or composite material with a temperature resistance exceeding 800°C.

[0010] The rough element array is arranged on the outer surface of the high temperature resistant skin, and its height does not exceed 5 mm.

[0011] The micropore array, air interface, air supply pipeline, air tank, and electromagnetic pressure reducing valve together constitute the microfluidic system. The micropore array is a through-hole array structure arranged in the heat-resistant skin. Together with the rough element array, it is arranged alternately along the airflow direction on the heat-resistant skin. The micropore diameter does not exceed 2 mm. The micropore array is connected to the air supply pipeline via the air interface installed on the inner surface of the heat-resistant skin. The air supply pipeline is connected to the air tank and the air flow is controlled by the electromagnetic pressure reducing valve.

[0012] The temperature controller, pressure sensor, and controller together constitute the state monitoring and feedback system for the thermal and drag reduction system. The temperature sensor, mounted on the inner surface of the high-temperature resistant skin, monitors the operating temperature of the skin and the roughness element array. The pressure sensor, embedded in the high-temperature resistant skin through a perforation, measures the ambient pressure on the skin surface. The temperature and pressure sensors input the measured temperature and pressure data into the controller, which determines flow control parameters based on this data and outputs signals to the solenoid pressure reducing valve to control valve opening and closing and output pressure.

[0013] In the application method of the high-speed aircraft heat reduction and drag reduction system based on combined flow control of rough elements and microjets, the rough element array arranged on the surface of the high-temperature resistant skin can achieve efficient drag reduction by regulating the boundary layer flow structure. Under the influence of continuous scouring of high-temperature and high-speed incoming flow, the temperature of the rough element array will continue to rise. When the operating temperature of the rough element array monitored by the temperature sensor approaches the safe temperature upper limit, the controller outputs a control signal based on the temperature monitoring data to open the electromagnetic pressure reducing valve, so that the microjet system enters the operating state. At the same time, the controller outputs a control signal based on the pressure monitoring data of the pressure sensor to adjust the output pressure of the electromagnetic pressure reducing valve so that the operating pressure of the microjet system matches the ambient pressure of the skin surface, thereby generating a large number of microjets in the micropore array area. These microjets can, on the one hand, achieve efficient heat reduction and drag reduction by regulating the boundary layer flow structure, and on the other hand, can form a layer of low-temperature air film near the wall to protect the rough element array, significantly reducing the aerodynamic heating and scouring effects on the rough element array, thereby ensuring the safe and stable operation of the rough element array. This method solves the thermal failure problem of rough element technology and the cooling medium consumption problem of microjet technology by combining the two flow control technologies of rough element and microjet, and can achieve the effect of reducing heat and drag with low cost and high reliability.

[0014] Compared with existing technologies, the present invention offers several advantages: First, by combining rough element array technology with microfluidics, leveraging their strengths to overcome their weaknesses, this approach addresses both the thermal failure issues of rough element technology and the cooling fluid consumption issues of microfluidics. This approach achieves low-cost, high-reliability heat and drag reduction, demonstrating both technological innovation and engineering practicality. Second, a feedback control system is established, enabling the combined flow control scheme to adjust its operating state and parameters in real time based on changes in the external flight environment and the aircraft's flight state, further enhancing its engineering practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the system of the present invention.

[0016] Figure 2 Schematic diagram of the layout of the rough element array and the microhole array of the present invention.

[0017] Explanation of the accompanying symbols: 1. High-temperature resistant skin; 2. Rough element array; 3. Micropore array; 4. Air path interface; 5. Air supply channel; 6. Air storage tank; 7. Solenoid pressure reducing valve; 8. Temperature sensor; 9. Pressure sensor; 10. Controller. DETAILED DESCRIPTION

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0019] like Figure 1As shown, a high-speed aircraft heat reduction and drag reduction system based on combined flow control of roughness elements and microjets comprises, in order, a high-temperature resistant skin 1, a roughness element array 2, a micropore array 3, an air path interface 4, an air supply line 5, an air tank 6, an electromagnetic pressure reducing valve 7, a temperature sensor 8, a pressure sensor 9, and a controller 10. The high-temperature resistant skin 1 is made of an alloy or composite material with a temperature resistance exceeding 800°C. The roughness element array 2 is arranged on the outer surface of the high-temperature resistant skin 1 and has a height not exceeding 5 mm. The roughness element array 2 can be formed on the high-temperature resistant skin 1 through processes such as machining and laser processing. Alternatively, a film containing the roughness element array 2 can be pre-fabricated and then bonded to the surface of the high-temperature resistant skin 1.

[0020] like Figure 1 As shown, the microfluidic system consists of a micropore array 3, an air interface 4, an air supply line 5, an air tank 6, and an electromagnetic pressure reducing valve 7. The micropore array 3 is connected to the air supply line 5 via the air interface 4 mounted on the inner surface of the high-temperature-resistant skin 1. The air supply line 5 is connected to the air tank 6, and the air flow is controlled by the electromagnetic pressure reducing valve 7. The air interface 4 is used to supply the air line 5 and ensure that the cooling gas is evenly distributed throughout the micropore array 3.

[0021] like Figure 2 As shown, the micropore array 3 is a through-hole array structure arranged in the high-temperature resistant skin 1, and is alternately arranged along the airflow direction on the high-temperature resistant skin 1 together with the rough element array 2, and the micropore diameter does not exceed 2 mm.

[0022] like Figure 1 As shown, the temperature controller 8, pressure sensor 9, and controller 10 together constitute the state monitoring and feedback system of the heat reduction and drag reduction system. The temperature sensor 8 is installed on the inner surface of the high-temperature resistant skin 1 and is used to monitor the operating temperature of the high-temperature resistant skin 1 and the rough element array 2. The temperature of the high-temperature resistant skin 1 can be directly measured by the temperature sensor 8, and the temperature of the rough element array 2 is obtained by constructing a mathematical model through ground calibration experiments and then performing online inversion calculations. The pressure sensor 9 is pre-buried in the high-temperature resistant skin 1 by punching a hole and is used to measure the ambient pressure on the skin surface. The temperature sensor 8 and the pressure sensor 9 input the measured temperature and pressure data into the controller 10. The controller 10 determines the flow control parameters based on these data and outputs a signal to the electromagnetic pressure reducing valve 7 to control the opening and closing of the valve and the output pressure.

[0023] like Figure 1 and Figure 2As shown, a high-speed aircraft heat reduction and drag reduction system based on combined flow control of roughness elements and microjets is shown. A roughness element array 2 arranged on the surface of a high-temperature resistant skin 1 can achieve efficient drag reduction by regulating the boundary layer flow structure. Due to the continuous scouring of high-temperature, high-speed incoming flow, the temperature of the roughness element array 2 will continue to rise. When the operating temperature of the roughness element array 2 detected by the temperature sensor 8 approaches the upper limit of the safe temperature, the controller 10 outputs a control signal based on the temperature monitoring data to open the electromagnetic pressure reducing valve 7, putting the microjet system into operation. At the same time, the controller 10 outputs a control signal based on the pressure monitoring data of the pressure sensor 9 to adjust the output pressure of the electromagnetic pressure reducing valve 7 so that the operating pressure of the microjet system matches the ambient pressure on the skin surface, thereby generating a large number of microjets in the area of ​​the micropore array 3. These microjets can achieve efficient heat reduction and drag reduction by regulating the boundary layer flow structure. On the other hand, they can form a low-temperature air film near the wall to protect the roughness element array 2, significantly reducing the aerodynamic heating and scouring effects on the roughness element array 2, ensuring the safe and stable operation of the roughness element array 2. This method solves the thermal failure problem of rough element technology and the cooling medium consumption problem of microjet technology by combining the two flow control technologies of rough element and microjet. It can achieve the effect of reducing heat and drag with high reliability at low cost, and its comprehensive performance is better than that of single flow control.

[0024] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above-mentioned embodiments. All technical solutions based on the principles of the present invention are within the scope of protection of the present invention. It should be noted that improvements and modifications that do not depart from the principles of the present invention are within the scope of protection of the present invention.

Claims

1. A heat and drag reduction system based on combined flow control of roughness elements and microjets, characterized by: It includes a high temperature resistant skin (1), a rough element array (2), a microporous array (3), an air path interface (4), an air supply pipeline (5), an air storage tank (6), an electromagnetic pressure reducing valve (7), a temperature sensor (8), a pressure sensor (9) and a controller (10); The rough element array (2) is arranged on the outer surface of the high temperature resistant skin (1); The microporous array (3), air path interface (4), air supply pipeline (5), air storage tank (6) and electromagnetic pressure reducing valve (7) together constitute a micro jet system; the microporous array (3) is a through-hole array structure arranged in the high-temperature resistant skin (1), and is alternately arranged on the high-temperature resistant skin (1) along the air flow direction together with the rough element array (2); the microporous array (3) is connected to the air supply pipeline (5) through the air path interface (4) installed on the inner surface of the high-temperature resistant skin (1); the air supply pipeline (5) is connected to the air storage tank (6), and the air path is controlled by the electromagnetic pressure reducing valve (7); The temperature sensor (8), pressure sensor (9) and controller (10) together constitute a state monitoring and feedback system for the heat reduction and drag reduction system; the temperature sensor (8) is installed on the inner surface of the high-temperature resistant skin (1) and is used to monitor the operating temperature of the high-temperature resistant skin (1) and the rough element array (2); the pressure sensor (9) is pre-buried in the high-temperature resistant skin (1) by punching a hole and is used to measure the ambient pressure on the skin surface; the temperature sensor (8) and the pressure sensor (9) input the measured temperature and pressure data into the controller (10), and the controller (10) determines the flow control parameters based on these data and outputs a signal to the electromagnetic pressure reducing valve (7) for controlling the opening and closing of the valve and the output pressure.

2. The heat and drag reduction system based on combined flow control of roughness elements and microjets according to claim 1, characterized in that: The high temperature resistant skin (1) is made of an alloy material or a composite material with a temperature resistance exceeding 800°C.

3. The heat and drag reduction system based on combined flow control of roughness elements and microjets according to claim 1, characterized in that: The height of the rough element array (2) does not exceed 5 mm.

4. The heat and drag reduction system based on combined flow control of roughness elements and microjets according to claim 1, characterized in that: The micropore diameter of the micropore array (3) does not exceed 2 mm.

5. The heat and drag reduction system based on combined flow control of roughness elements and microjets according to claim 1, characterized in that: Used in high-speed aircraft.

6. A method for applying the heat and drag reduction system based on combined flow control of roughness elements and microjets as claimed in claim 1, characterized in that: The rough element array (2) arranged on the surface of the high-temperature resistant skin (1) realizes efficient drag reduction by regulating the boundary layer flow structure. Under the influence of the continuous scouring of the high-temperature and high-speed incoming flow, the temperature of the rough element array (2) continues to rise. When the operating temperature of the rough element array (2) monitored by the temperature sensor (8) reaches the set upper limit temperature, the controller (10) outputs a control signal according to the temperature monitoring data to open the electromagnetic pressure reducing valve (7), so that the micro-jet system enters the operating state. At the same time, the controller (10) outputs a control signal according to the pressure monitoring data of the pressure sensor (9) to adjust the output pressure of the electromagnetic pressure reducing valve (7), so that the operating pressure of the micro-jet system matches the ambient pressure of the skin surface, thereby generating a large number of micro-jets in the micro-hole array (3) area.

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