A high-speed flow rapid mixing device, mixing method and engine thereof

Abstract

The present invention belongs to the field of engines, and specifically relates to a high-speed flow rapid mixing device, a mixing method and an engine thereof, wherein the high-speed flow rapid mixing device comprises a wall plate I, a partition plate and a wall plate II arranged in sequence; an airflow channel I is formed between the wall plate I and the partition plate; an airflow channel II is formed between the wall plate II and the partition plate; an airflow mixing chamber is formed between the wall plate I and the wall plate II and at a downstream position of the downstream end of the partition plate; a shock wave generator is provided on the wall plate I and / or the wall plate II, and the shock wave generator is used to generate an oblique shock wave directed toward the airflow mixing chamber. The present invention has the characteristics of simple structure, small flow resistance and total pressure loss, and outstanding mixing effect.

Description

Technical Field

[0001] The invention belongs to the field of engines, and in particular relates to a high-speed flow rapid mixing device, a mixing method and an engine thereof. Background Art

[0002] Hypersonic aircraft refers to high-speed aircraft that fly in the atmosphere or across the atmosphere with a flight Mach number greater than 5, and has important application value. Ramjets and their combined power engines are the technical core of the development of hypersonic aircraft. For this type of engine, the speed of the incoming air compressed by the inlet is supersonic, and after mixing with the high-speed fuel jet in the mixing chamber, energy conversion is achieved through combustion, thereby realizing engine operation. Among them, due to the limitation of the size of the entire engine, the length of the mixing chamber is limited, and the space that can be provided for high-speed air and gas mixing is very tight. In addition, the incoming air under supersonic conditions has strong compressibility, and the compressibility significantly inhibits the mixing of the flow, which poses a great challenge to the rapid and efficient mixing of gas and air.

[0003] In order to improve the mixing efficiency, domestic and foreign scholars have made great efforts in the past few decades and proposed a series of enhanced mixing measures. Based on the principle of mixing enhancement, it can be divided into two types: passive and active enhanced mixing. The flow control method of passive mixing enhancement achieves mixing enhancement by installing some fixed devices in the flow field.

[0004] The prior art proposes a scheme for realizing supersonic mixing layer enhanced mixing by using sinusoidal and rectangular lobe mixer devices. It is found that the sinusoidal shape has a superior mixing effect, and the wavelength ratio has a great influence on the mixing effect. Through dimensional analysis, it is found that a positive mixing effect will occur when the dimensionless wavelength ratio is greater than 1, and when the dimensionless wavelength ratio is 1.905, the growth rate of the mixing layer thickness increases by nearly 12%. However, since this type of structure has a fixed geometry and the incoming flow conditions remain unchanged, its enhanced mixing effect lacks adaptability to a wide range of working conditions.

[0005] The prior art has also studied inducing shock wave structures by installing ramp devices in the flow field, and achieving enhanced mixing through the interaction of shock wave mixing layers, and has achieved certain results. However, due to the fixed geometric structure characteristics of the ramp device, the shock wave and the mixing layer can only act at a single point, and the control effect on the far field of the flow is very limited.

[0006] Active enhanced mixing schemes require the introduction of external energy (in the form of heat, mass and / or momentum) into the flow field to achieve flow control. Depending on the control purpose that the flow needs to achieve, the external actuator can input an excitation of a specific frequency and amplitude. The advantage of active control technology is that the position and parameters of the excitation are easy to control. The prior art also proposes a plasma actuator device for mixing with supersonic jets, which can independently control their frequency, phase and duty cycle within a very wide frequency band to drive these actuators, which is very suitable for open-loop and closed-loop active flow control to achieve high-speed jet enhancement. However, since it is a purely active control method, its control effect on supersonic flows with high Mach numbers (greater than 3) is very limited.

[0007] It can be found that the passive reinforcement hybrid technology that has been proposed has poor adaptability over a wide range, and the active reinforcement hybrid technology has the disadvantages of being difficult to apply at high Mach numbers. There is an urgent need to propose a new type of hybrid reinforcement scheme to support the realization of efficient propulsion of aerospace power systems. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a high-speed flow rapid mixing device, a mixing method and an engine thereof which have a simple structure, small flow resistance and total pressure loss and outstanding mixing effect.

[0009] The present invention provides a high-speed flow rapid mixing device, comprising a wall plate I, a partition plate and a wall plate II which are sequentially arranged at intervals;

[0010] An airflow channel I for flowing airflow I is formed between the wall plate I and the partition plate;

[0011] An airflow channel II for flowing airflow II is formed between the wall plate II and the partition plate;

[0012] An airflow mixing chamber for mixing the airflow I and the airflow II is formed between the wall plate I and the wall plate II and located downstream of the downstream end of the partition plate;

[0013] A shock wave generator is arranged on the wall panel I and / or the wall panel II, and the shock wave generator is used to generate an oblique shock wave directed toward the airflow mixing cavity.

[0014] Furthermore, the shock wave generator comprises a slope, and the deflection angle of the slope is adjustable.

[0015] Furthermore, the deflection angle of the slope can be changed periodically and reciprocatingly.

[0016] Furthermore, the shock wave generator comprises a slope, and the deflection angle of the slope is 3°-20°.

[0017] Furthermore, the shock wave generator comprises a slope, and the length of the slope is 55mm-65mm.

[0018] Furthermore, the shock wave generator comprises a slope, and the slope is arranged at 75 mm-85 mm away from the downstream end of the partition plate.

[0019] Furthermore, the airflow I is supersonic fuel-rich combustion gas; and the airflow II is supersonic incoming air.

[0020] The present invention provides a high-speed flow rapid mixing method, using the high-speed flow rapid mixing device, comprising the following steps:

[0021] Airflow I flows from the airflow channel I to the airflow mixing chamber;

[0022] Airflow II flows from the airflow channel II to the airflow mixing chamber;

[0023] Airflow I and airflow II meet at the lower end of the partition plate to form a mixed layer;

[0024] When airflow I and / or airflow II pass through the shock generator, an oblique shock wave is generated. The oblique shock wave is injected into the transition region of the mixing layer, causing the large-scale vortex structure in the flow field to be broken, enhancing the three-dimensional characteristics of the flow field, and at the same time changing the local vorticity distribution of the flow field, causing a significant increase in the vorticity thickness, thereby improving the mixing efficiency of airflow I and airflow II.

[0025] Furthermore, the deflection angle of the shock wave generator changes reciprocally periodically;

[0026] When airflow I and / or airflow II passes through the shock generator, an oscillating oblique shock wave with a wide range of motion is induced. The oscillating oblique shock wave interacts with the mixing layer in a wide range of flow directions, thereby achieving mixing enhancement of the mixing layer over a longer distance.

[0027] The present invention also provides an engine, comprising the above-mentioned high-speed flow rapid mixing device.

[0028] The beneficial effect of the present invention is that in the high-speed flow rapid mixing device provided by the present invention, airflow I and airflow II on the side close to the partition plate meet at the downstream end of the partition plate and mix with each other in the form of shear to form a mixing layer. When airflow I and / or airflow II pass through the shock wave generator on the side away from the partition plate, the airflow is deflected to form an oblique shock wave. The oblique shock wave passes through airflow I and / or airflow II and is injected into the mixing layer, and then interacts with the mixing layer. On the one hand, it can significantly cause the fragmentation of large-scale vortex structures in the flow field and enhance the three-dimensional characteristics of the flow field. On the other hand, the incidence of the oblique shock wave can significantly change the local vortex distribution of the flow field, causing a significant increase in the vortex thickness, thereby improving the mixing efficiency of airflow I and airflow II.

[0029] That is, the high-speed flow rapid mixing device of the present invention has relatively little improvement on the flow channel, and has the characteristics of simple structure, small flow resistance and total pressure loss, and outstanding mixing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Attached Figure 1 A schematic diagram of the structure of a device for high-speed flow and rapid mixing;

[0031] Attached Figure 2 Schematic diagram of the flow field of the device for high-speed flow rapid mixing.

[0032] In the figure, 1-airflow I; 2-airflow II; 3-wall panel I; 4-partition plate; 5-wall panel II; 6-airflow channel I; 7-airflow channel II; 8-airflow mixing chamber; 9-shock wave generator; 91-ramp; 92-rotational drive mechanism; 10-oblique shock wave; 11-mixing layer; 12-action area of ​​oscillating oblique shock wave and mixing layer. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0035] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0036] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0038] As attached Figure 1 -Attached Figure 2 As shown, the present invention provides a high-speed flow rapid mixing device, comprising a wall plate Ⅰ3, a partition plate 4 and a wall plate Ⅱ5 arranged in sequence, preferably, the wall plate Ⅰ3, the partition plate 4 and the wall plate Ⅱ5 are parallel to each other; preferably, the wall plate Ⅰ3 and the wall plate Ⅱ5 are symmetrically arranged;

[0039] An airflow channel Ⅰ6 for the flow of airflow Ⅰ1 is formed between the wall plate Ⅰ3 and the partition plate 4;

[0040] An airflow channel II7 for the flow of airflow II2 is formed between the wall plate II5 and the partition plate 4;

[0041] An airflow mixing chamber 8 for mixing the airflow I1 and the airflow II2 is formed between the wall plate I3 and the wall plate II5 and at a position downstream of the downstream end of the partition plate 4, that is, the downstream end of the partition plate 4 is located upstream of the downstream ends of the wall plate I3 and the wall plate II5. Preferably, the upstream end of the partition plate 4 is flush with the upstream ends of the wall plate I3 and the wall plate II5, and at this time, the flow length of the partition plate 4 is shorter than the flow length of the wall plate I3 and the wall plate II5;

[0042] A shock wave generator 9 is arranged on the wall panel I3 and / or the wall panel II5, that is, the shock wave generator 9 can be arranged only on the wall panel I3, or only on the wall panel II5, or on both the wall panel I3 and the wall panel II5. The shock wave generator 9 is used to generate an oblique shock wave 10 directed toward the airflow mixing chamber 8.

[0043] The high-speed flow rapid mixing device provided by the present invention is that after the airflow I1 and the airflow II2 meet at the downstream end of the partition plate 4 on the side close to the partition plate 4, they will mix with each other in the form of shear and form a mixing layer 11. When the airflow I1 and / or the airflow II2 pass through the shock generator 9 on the side away from the partition plate 4, the airflow is deflected to form an oblique shock wave 10. The oblique shock wave 10 passes through the airflow I1 and / or the airflow II2 and is injected into the mixing layer 11, and then interacts with the mixing layer 11. On the one hand, it can significantly cause the fragmentation of the large-scale vortex structure in the flow field and enhance the three-dimensional characteristics of the flow field; on the other hand, the incidence of the oblique shock wave 10 can significantly change the local vortex distribution of the flow field, resulting in a significant increase in the vortex thickness, thereby improving the mixing efficiency of the airflow I1 and the airflow II2.

[0044] That is, the high-speed flow rapid mixing device of the present invention has relatively little improvement on the flow channel, and has the characteristics of simple structure, small flow resistance and total pressure loss, and outstanding mixing effect.

[0045] In one of the embodiments, the shock wave generator 9 includes a slope 91, and the deflection angle of the slope 91 is adjustable. In this embodiment, by adjusting the angle of the slope 91, on the one hand, the flow loss of the flow field caused by the slope 91 can be controlled, and on the other hand, according to the different Mach numbers of the airflow I1 and / or the airflow II2, the incident angle of the oblique shock wave 10 can be adjusted, and finally the position of the oblique shock wave 10 entering the mixing layer 11 can be adjusted, thereby improving the wide range of practicality of the flow field control.

[0046] In one of the embodiments, the deflection angle of the slope 91 can be changed periodically and reciprocally, that is, the slope 91 can oscillate at a specific frequency. In this embodiment, due to the periodic reciprocating change of the deflection angle of the slope 91, the action position of the incident oblique shock wave 10 and the mixing layer 11 will move back and forth within the forward and backward range of the flow, forming an oscillating oblique shock wave, and the action behavior of the oscillating oblique shock wave and the mixing layer 11 in a certain area; that is, the slope 91 can induce an oscillating oblique shock wave with a wide range of motion, and can make the generated oscillating oblique shock wave act on the transition area of ​​the mixing layer 11, so as to realize the effective action of the oscillating oblique shock wave and the mixing layer 11 in the wide range of the flow direction, thereby further enhancing the three-dimensional fragmentation characteristics and vorticity distribution characteristics of the mixing layer 11, and further improving the mixing efficiency of the airflow I1 and the airflow II2.

[0047] In addition, the periodic reciprocating change of the deflection angle of the slope 91 can also overcome the deficiency that the traditional fixed slope device can only achieve single-point effect on the induced shock wave and mixing layer. By controlling the oscillation frequency and oscillation amplitude of the slope 91, the technical advantages of active and passive mixing enhancement can also be combined, which has a wider applicability.

[0048] In an embodiment in which the deflection angle of the slope 91 is adjustable or the deflection angle can be changed periodically, the upstream end face of the slope 91 is rotationally connected to the wall panel I3 and / or the wall panel II5, that is, the wall panel I3 and / or the wall panel II5 are provided with an accommodating hole, and the upstream end face of the slope 91 is rotationally connected to the upstream hole wall of the accommodating hole, and the shock wave generator 9 also includes a rotation driving mechanism 92 for driving the slope 91 to rotate along its upstream end face.

[0049] In one of the embodiments, in order to allow the incident oblique shock wave 10 to fully interact with the mixing layer 11 to enhance mixing while minimizing flow losses, the deflection angle range of the slope 91 should not be too large. The deflection angle of the slope 91 is 3°-20°; preferably 5°-18°, so as to ensure that the oscillating oblique shock wave 10 can interact with the mixing layer 11 in the entire transition region to promote mixing.

[0050] In the embodiment in which the deflection angle of the slope 91 can be adjusted, the deflection angle of the slope 91 is adjusted between 3° and 20°, preferably between 5° and 18°.

[0051] In the embodiment where the deflection angle of the slope 91 can be periodically changed, the deflection angle of the slope 91 is periodically changed between 3° and 20°, and preferably between 5° and 18°.

[0052] In one embodiment, in order to reduce the weight of the structure, the length of the slope 91 should not be too long, and the length of the slope 91 is 55mm-65mm, preferably 60mm. It should be noted that the length of the slope 91 refers to the length of the slope 91 projected on the wall panel I3 or the wall panel II5.

[0053] In one of the embodiments, in order to enable the generated oblique shock wave 10 to act on the transition region of the mixing layer 11, the slope 91 is set at 75mm-85mm, preferably 80mm, from the downstream end of the partition plate 4.

[0054] In one embodiment, the airflow I1 is supersonic fuel-rich gas, and the airflow II2 is supersonic incoming air. Preferably, the slope 91 is arranged on the wall plate I3 to guide the supersonic fuel-rich gas to deflect and form a supersonic fuel-rich gas oblique shock wave.

[0055] The present invention also provides a high-speed flow rapid mixing method, using the high-speed flow rapid mixing device, comprising the following steps:

[0056] The airflow I1 flows from the airflow channel I6 to the airflow mixing chamber 8;

[0057] The airflow II2 flows from the airflow channel II7 to the airflow mixing chamber 8;

[0058] After the airflow I1 and the airflow II2 meet at the lower end of the partition plate 4, they begin to mix in a shearing manner and form a mixed layer 11;

[0059] The airflow I1 and / or airflow II2 are deflected when passing through the shock generator 9, generating an oblique shock wave 10. The oblique shock wave 10 is injected into the transition region of the mixing layer 11, causing the large-scale vortex structure in the flow field to be broken, thereby enhancing the three-dimensional characteristics of the flow field and changing the local vorticity distribution of the flow field, resulting in a significant increase in the vorticity thickness, thereby improving the mixing efficiency of the airflow I1 and the airflow II2.

[0060] In one embodiment, the deflection angle of the shock wave generator 9 changes reciprocatingly periodically;

[0061] When the airflow I1 and / or the airflow II2 passes through the shock wave generator 9, an oscillating oblique shock wave with a wide range of motion is induced. The oscillating oblique shock wave interacts with the mixing layer 11 in a wide range of flow directions, thereby achieving mixing enhancement of the mixing layer 11 over a longer distance. Figure 2 In the figure, mark 10a is the position of the oblique shock wave when the slope has the maximum deflection angle, mark 10b is the position of the oblique shock wave when the slope has the minimum deflection angle, and mark 12 is the interaction area between the oscillating oblique shock wave and the mixing layer.

[0062] In a preferred embodiment, the oscillation frequency and oscillation amplitude of the oscillating oblique shock wave can be controlled by controlling the frequency and amplitude of the ramp 91, that is, the technical advantages of active and passive hybrid enhancement can be combined, which has a wider applicability.

[0063] The present invention also provides an engine, comprising the above-mentioned high-speed flow rapid mixing device.

[0064] The above is only an embodiment and does not limit the present invention in any way. Any person skilled in the art can use the above disclosed technical contents to make many possible changes, modifications or modifications to the technical solutions of the present invention into equivalent embodiments of equivalent changes without departing from the scope of the technical solutions of the present invention. Therefore, any simple modification, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the scope of protection of the technical solutions of the present invention.

Claims

1. A high-speed flow rapid mixing device, characterized in that: It comprises a wall panel I (3), a partition panel (4) and a wall panel II (5) which are arranged in sequence at intervals; An air flow channel I (6) for the flow of air flow I (1) is formed between the wall plate I (3) and the partition plate (4); An air flow channel II (7) for the flow of air flow II (2) is formed between the wall plate II (5) and the partition plate (4); An airflow mixing chamber (8) for mixing the airflow I (1) and the airflow II (2) is formed between the wall plate I (3) and the wall plate II (5) and located downstream of the downstream end of the partition plate (4); A shock wave generator (9) is provided on the wall panel I (3) and / or the wall panel II (5), and the shock wave generator (9) is used to generate an oblique shock wave (10) directed toward the airflow mixing chamber (8); The shock wave generator (9) comprises a slope (91), and the deflection angle of the slope (91) is adjustable; The deflection angle of the slope (91) can be changed periodically and reciprocally.

2. The high-speed flow rapid mixing device as claimed in claim 1, characterized in that: The shock wave generator (9) comprises a slope (91), and the deflection angle of the slope (91) is 3°-20°.

3. The high-speed flow rapid mixing device as claimed in claim 1, characterized in that: The shock wave generator (9) comprises a slope (91), and the length of the slope (91) is 55 mm-65 mm.

4. The high-speed flow rapid mixing device as claimed in claim 1, characterized in that: The shock wave generator (9) comprises a slope (91), and the slope (91) is arranged at a distance of 75 mm to 85 mm from the downstream end of the partition plate (4).

5. The high-speed flow rapid mixing device as claimed in claim 1, characterized in that: The airflow I (1) is supersonic fuel-rich combustion gas; the airflow II (2) is supersonic incoming air.

6. A high-speed flow rapid mixing method, characterized in that: Using the high-speed flow rapid mixing device as described in any one of claims 1 to 5 comprises the following steps: The airflow I (1) flows from the airflow channel I (6) to the airflow mixing chamber (8); The airflow II (2) flows from the airflow channel II (7) to the airflow mixing chamber (8); Airflow I (1) and airflow II (2) meet at the lower end of the partition plate (4) to form a mixed layer (11); When the airflow I (1) and / or the airflow II (2) passes through the shock wave generator (9), an oblique shock wave (10) is generated. The oblique shock wave (10) is injected into the transition region of the mixing layer (11), causing the large-scale vortex structure in the flow field to be broken up, thereby enhancing the three-dimensional characteristics of the flow field and changing the local vorticity distribution of the flow field, causing a significant increase in the vorticity thickness, thereby improving the mixing efficiency of the airflow I (1) and the airflow II (2).

7. The high-speed flow rapid mixing method as claimed in claim 6, characterized in that: The deflection angle of the shock wave generator (9) changes reciprocatingly in a periodic manner; When the airflow I (1) and / or the airflow II (2) passes through the shock wave generator (9), an oscillating oblique shock wave with wide-range motion is induced. The oscillating oblique shock wave interacts with the mixing layer (11) in a wide range of flow directions, thereby achieving mixing enhancement of the mixing layer (11) over a longer distance.

8. An engine, characterized in that: A high-speed flow rapid mixing device comprising the device as described in any one of claims 1 to 5.

Images