Flow control method and device for internal flow passage of engine

Abstract

The present invention relates to a method and device for flow control in an engine internal flow passage. The method includes: arranging a control plate at the engine intake passage to regulate the flow mode in the flow passage through the control plate; when the control plate is perpendicular to the air incoming flow, the intake passage is in a closed state to block the backflow of high-temperature products generated by combustion heat release and the forward transmission of back pressure, and ensure the positive reflection of the pressure wave system at the closed end; when the control plate reciprocally rotates along the rotating shaft, an equivalent Laval nozzle configuration is formed, and a strong turbulence flow field for enhancing the mixing degree of reactants is formed; when the control plate is parallel to the air incoming flow, the intake resistance is small, thereby achieving low-resistance and fast intake. By actively controlling the flow mode in the engine internal flow passage through the control plate, the present invention can not only achieve low-resistance and fast intake, enhance the mixing degree of reactants, but also efficiently block the backflow of combustion products and the forward transmission of back pressure, thereby improving the thrust performance of the supercharged combustion engine.

Description

Technical Field

[0001] The present invention relates to the technical field of engine flow control, and in particular to a flow control method and device for an engine inner flow channel. Background Art

[0002] As the core power source for starting various equipment, the performance of the engine is directly related to the operating efficiency and performance of various equipment. By effectively controlling the internal flow channel of the engine, the performance of the engine can be effectively improved.

[0003] However, in the traditional inner flow channel design, high-temperature and high-pressure products are prone to reverse flow and forward transmission during combustion, which causes some products to remain in the inner flow channel for a long time and require multiple cycles of reciprocating motion to be discharged. This will lead to low exhaust efficiency of the engine, causing a large loss of engine thrust and affecting the overall performance of the engine.

[0004] In addition, the traditional inner flow channel also has certain obstacles in terms of air intake. For example, the traditional mechanical valve control, due to its own high blockage, greatly increases the intake resistance, making it difficult for fresh air to enter the inner flow channel in sufficient quantity and smoothly, and cannot meet the intake demand for efficient operation of the engine, limiting the potential of the engine. Summary of the invention

[0005] Based on this, it is necessary to provide a flow control method and device for the flow channel inside the engine that can solve the problem of reverse flow forward transmission, achieve low-resistance and rapid air intake, and enhance the degree of mixing of reactants in response to the above-mentioned technical problems.

[0006] A flow control method for a flow passage in an engine, the method comprising: providing a control panel at an engine air intake, and regulating the flow pattern in the flow passage by means of the control panel;

[0007] When the control plate is perpendicular to the incoming air flow, the air inlet is in a closed state to block the backflow and forward transmission of the high-temperature products generated by the combustion heat release, and to ensure the positive reflection of the pressure wave system at the closed end;

[0008] When the control plate reciprocates and rotates along the rotating shaft, an equivalent Laval nozzle configuration is formed, and a high turbulence flow field is formed to enhance the mixing degree of reactants;

[0009] When the control plate is parallel to the incoming air flow, the air intake resistance is small, thereby achieving low-resistance and fast air intake.

[0010] A flow control device for an internal flow channel of an engine comprises: a control plate arranged at the entrance of an air intake channel, one end of the control plate being fixed to the inner wall surface of the air intake channel via a rotating shaft, and the other end being a rotating end; the rotating end has a stroke of reciprocating rotational motion centered on the rotating shaft.

[0011] The above-mentioned flow control method and device for the internal flow path of the engine regulate the flow mode in the flow path by setting a control plate at the engine intake passage. When the control plate is perpendicular to the oncoming air flow, the intake passage is in a closed state to block the reverse flow of high-temperature products generated by combustion heat release and the forward transmission of back pressure, and ensure the positive reflection of the pressure wave system at the closed end. When the control plate reciprocally rotates along the rotating shaft, an equivalent Laval nozzle configuration is formed, and a strong turbulent flow field that enhances the mixing degree of reactants is formed. When the control plate is parallel to the oncoming air flow, the intake resistance is small, thus realizing low-resistance and rapid intake. By actively controlling the flow mode of the internal flow path of the engine through the control plate, the present invention can not only achieve low-resistance and rapid intake, enhance the mixing degree of reactants, but also efficiently block the reverse flow of combustion products and the forward transmission of back pressure, thereby improving the thrust performance of the supercharged combustion engine. Brief Description of the Drawings

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following-described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0013] Figure 1 It is a schematic flow chart of the flow control method for the internal flow path of the engine in an embodiment;

[0014] Figure 2 It is a schematic diagram of the working principle of the flow control method for the internal flow path of the engine in an embodiment;

[0015] Figure 3 It is a schematic diagram of the supercharged combustion process with a transient pressure ratio as high as 5.8 under a stationary air flow in an embodiment;

[0016] Figure 4 It is a schematic diagram of the supercharged combustion process with a transient pressure ratio as high as 4.2 under a Ma0.8 air flow in an embodiment.

[0017] Description of the Reference Numerals in the Drawings:

[0018] Oncoming air flow 1, internal flow path 2 of the engine, upper wall surface 21, lower wall surface 22, control plate 3, rotating shaft 4, throat 5, locally supersonic flow field region 6, subsonic flow field region 7, unsteady flow field 8, normal shock wave 9, fuel injection region 10.

[0019] The realization of the object, functional features and advantages of the present invention will be further described in conjunction with the embodiments with reference to the drawings. Detailed Embodiments

[0020] 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.

[0021] 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.

[0022] It can be understood that 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.

[0023] The following will describe the implementation of the present invention in detail with reference to the accompanying drawings in the embodiment diagram of the present invention.

[0024] Example 1

[0025] The present embodiment discloses a flow control method for an engine internal flow channel, which can realize low-resistance and rapid air intake, enhance the degree of mixing of reactants, and effectively block the backflow and forward transmission of combustion products, thereby improving the thrust performance of a supercharged combustion engine, through active control of a control plate.

[0026] like Figure 1 and Figure 2 As shown, the flow control method of the flow channel in the engine provided by this embodiment includes the following steps:

[0027] Step 201, a control panel is provided at the engine air intake, and the flow pattern in the flow channel is regulated by the control panel.

[0028] Specifically, see Figure 2 The upper wall surface 21 and the lower wall surface 22 form a simple engine inner flow channel 2, and a control board 3 is arranged at the inlet of the air inlet. The control board 3 has a stroke of reciprocating rotation around the rotating shaft 4, and the flow mode in the flow channel is regulated by such a reciprocating rotation stroke.

[0029] Step 202, when the control panel 3 is perpendicular to the air inflow, the air inlet is in a closed state to block the backflow of high-temperature products generated by combustion heat release and the forward transmission of back pressure, and ensure the positive reflection of the pressure wave system at the closed end.

[0030] It can be understood that when the control panel 3 is perpendicular to the air inflow, the included angle between the control panel 3 and the cross-section of the air inlet is 0°, that is, the control panel is completely closed. As a rigid thrust wall, it can ensure that the air inlet is in a closed state, effectively blocking the backflow of high-temperature products generated by combustion heat release and the forward transmission of back pressure, and ensuring the positive reflection of the pressure wave system at the closed end, thereby maximizing the thrust performance.

[0031] Step 203, when the control panel 3 reciprocally rotates along the rotating shaft, an equivalent Laval nozzle configuration is formed, and a strong turbulent flow field that enhances the mixing degree of reactants is formed.

[0032] It can be understood that the reactants usually refer to the mixture of air and fuel after mixing, and the types of fuel usually include two types: gaseous fuel and liquid fuel.

[0033] When the control panel 3 reciprocally rotates along the rotating shaft, a process similar to a fan reciprocally fanning is formed. During the fanning process, an equivalent Laval nozzle configuration can be formed between the rotating end of the control panel 3 and the upper wall surface 21, thereby forming a throat 5 and improving the flow field structure downstream in the internal flow path 2 of the engine, enhancing the mixing effect of the reactants.

[0034] Step 204, when the control panel 3 is parallel to the air inflow 1, the intake resistance is small, thereby achieving low-resistance and fast air intake.

[0035] It can be understood that the control panel 3 rotates along the rotating shaft towards the combustion chamber direction. When it is completely parallel to the air inflow 1, a 90° included angle is formed. In this state, the control panel 3 is completely opened, and the air flow in the internal flow path 2 of the engine is in an unobstructed state, with the minimum intake resistance. Thus, it can refill enough fresh air quickly with low resistance, enhancing the combustion effect.

[0036] In one embodiment, when the control panel 3 reciprocally rotates along the rotating shaft 4, the angle when the control panel 3 is perpendicular to the air inflow 1 is regarded as 0°, and the angle when the control panel 3 is parallel to the air inflow 1 is regarded as 90°. Then, one reciprocating rotation of the control panel 3 from 0° to 90° is a cycle.

[0037] It can be understood that in this embodiment, the rotation stroke range of the control plate 3 is 0° to 90°, and the flapping direction is preferably towards the fuel injection area 10. By restricting the rotation stroke, it can effectively prevent the control plate 3 from excessive movement, which may lead to an air flow rate that is too large or too small and beyond the reasonable range. At the same time, controlling the rotation direction can make the incoming air flow better to the downstream, ensuring that the fuel contacts enough air in the first time. And this periodic reciprocating flapping can make the mixing process of air and fuel in the combustion chamber faster and more effective, thus achieving a better mixing effect.

[0038] Specifically, within one rotation period of the control plate 3 along the rotating shaft 4, there is a critical angle. When the air incoming flow 1 is a subsonic incoming flow, the control plate 3 rotates between 0° and the critical angle. The subsonic incoming flow is accelerated through the equivalent Laval nozzle configuration to form a sonic throat, and a local supersonic flow field region 6 and a subsonic flow field region 7 are formed behind the control plate 3. When the control plate 3 rotates between the critical angle and 90°, the subsonic incoming flow remains subsonic at the throat 5, and a subsonic flow field region 7 is formed behind the throat. The velocity distributions in different regions of the flow field are different, and a large number of vortices are generated, thereby enhancing the mixing degree of the reactants.

[0039] It should be noted that in this embodiment, a certain critical value reached by the rotation of the control plate 3 is used as the critical angle, and the concept of the critical angle is used to describe the change of the internal flow field of the engine within one rotation period of the control plate 3. That is to say, the critical angle represents a critical angle at which the velocity at the throat 5 decreases from sonic speed to subsonic speed, and it is not specified as a specific angle value.

[0040] It can be understood that during the flapping process of the control plate 3, the included angle increases from 0° to 90°, and the throat 5 gradually widens. When the control plate 3 increases from 0° to a certain critical value, a local supersonic flow field region 6 and a subsonic flow field region 7 are formed behind the control plate 3. When the control plate 3 increases from a certain critical value to 90°, the subsonic incoming flow remains subsonic at the throat 5, and a subsonic flow field region 7 is formed behind the throat. On the contrary, when the included angle decreases from 90° to 0°, the throat 5 gradually narrows. When it decreases from 90° to a certain critical value, the subsonic incoming flow remains subsonic at the throat 5, and a subsonic flow field region 7 is formed behind the throat. When it decreases from a certain critical value to 0°, a local supersonic flow field region 6 and a subsonic flow field region 7 are formed behind the control plate 3.

[0041] In addition, when the air incoming flow 1 is a supersonic incoming flow, the supersonic incoming flow is decelerated through the equivalent Laval nozzle configuration to form a sonic throat, and a local supersonic flow field region 6 and a subsonic flow field region 7 are formed behind the control plate 3.

[0042] In one embodiment, when the control plate 3 reciprocates along the rotating shaft 4, the rotating end of the control plate 3 induces an unsteady flow field 8 and forms an unsteady high turbulence flow field near the fuel injection area 10, thereby enhancing the mixing degree of the reactants.

[0043] In one of the embodiments, when the control plate 3 reciprocates along the rotating shaft 4, a positive shock wave 9 is generated downstream of the flow channel 2 in the engine; the positive shock wave 9 meets the fuel injected by the fuel injection area 10, further enhancing the mixing of the reactants to form an explosive combustion gas that is close to premixed.

[0044] It can be understood that the reciprocating rotation of the control plate 3 is a reciprocating periodic fanning process. In the reciprocating fanning process, the angle of the rotating end of the control plate 3 first increases from 0° to 90°, which is the first half cycle; then it rotates back from 90° to 0°, forming the second half cycle; repeating this cycle process, forming a reciprocating periodic fanning.

[0045] Through this reciprocating periodic flapping, on the one hand, it is possible to induce an unsteady flow field 8, which includes periodic vortex generation, shedding and fragmentation evolution processes. In this way, an unsteady strong turbulence flow field is formed near the fuel injection area 10, and the mixing enhancement of the reactants is initially achieved. On the other hand, this reciprocating periodic flapping will also generate an unstable positive shock wave 9 in the flow channel 2 of the engine, which is pushed downstream at any time; when the positive shock wave 9 meets the fuel injected by the fuel injection area 10, it can further enhance the mixing effect of the reactants, forming a nearly premixed explosive gas, and providing a nearly premixed explosive gas condition for achieving a thrust performance of high specific impulse output after ignition.

[0046] In one embodiment, the flow control method of the flow channel in the engine proposed by the present invention is verified. An arbitrary engine device is used, whose inlet cross-sectional size is 50mm×50mm, the outlet cross-sectional size is Φ40mm, and the total length is 800mm. The test results are as follows Figure 3 and Figure 4 As shown, through ignition tests under different incoming flow Mach numbers, equipped with the method proposed by the present invention, a supercharged combustion process with a large transient supercharging ratio was achieved.

[0047] The flow control method for the flow channel in the engine provided in this embodiment can realize a periodic combustion mode of high-frequency self-sustaining and high specific impulse output of a supercharged combustion engine. It can realize low-resistance and fast air intake in a simple flow channel 2 in the engine at a low Mach number (Ma0~Ma3.0), and can also enhance the mixing degree of reactants, and efficiently block the backflow and back pressure forward transmission of combustion products, effectively improve the thrust performance of the engine, and has a wide range of applications.

[0048] Although this embodiment Figure 1The steps in [description] are shown in sequence according to the arrows, but these steps do not necessarily need to be executed in the order indicated by the arrows. Unless otherwise explicitly stated in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 1 At least some of the steps in [description] may include multiple sub-steps or multiple stages. These sub-steps or stages do not necessarily need to be completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages does not necessarily need to be sequential, but can be executed alternately or in rotation with at least some of the sub-steps or stages of other steps or other steps.

[0049] Embodiment 2

[0050] Based on the flow control method of the engine internal flow passage in Embodiment 1, this embodiment discloses a flow control device for the engine internal flow passage. The flow control device for the engine internal flow passage includes a control plate 3 provided at the inlet of the intake passage. One end of the control plate 3 is fixed in the engine internal flow passage 2 through a rotating shaft 4 on the inner wall surface at the inlet of the intake passage, and the other end is a rotating end; the rotating end has a stroke of reciprocating rotational movement centered on the rotating shaft 4 to regulate the flow mode in the engine internal flow passage 2.

[0051] Specifically, the rotating end of the control plate 3 makes a periodic reciprocating rotational movement with one reciprocating rotation from 0° to 90° as a cycle. A driving member is also provided. The rotating shaft 4 is mechanically fixed on the driving member, and the movement of the rotating shaft is controlled through the driving member, thereby driving the control plate 4 to make a reciprocating rotational movement centered on the rotating shaft 4. In addition, the shape of the control plate 3 is adapted to the cross-sectional shape at the inlet of the intake passage. When the control plate 3 is installed at the inlet of the intake passage, it has a clearance fit with the wall surface of the engine internal flow passage. When the control plate 3 is vertically arranged, the intake passage can be in a closed state. Preferably, the driving member can be a motor or an electric machine; the control plate 3 can adopt a flat valve plate structure.

[0052] It can be seen that the device provided in this embodiment has a simple structure and is easy to apply. The movement of the control plate 3 can be easily driven by a motor or an electric machine, without the need for a complex driving device and a high-precision synchronous control system to adjust the rotation speed, reducing the complexity and cost of the entire system, having high economic value, and broad application prospects.

[0053] In this embodiment, the specific working process and working principle of the flow control device for the internal flow path of the engine are the same as those of the method in Embodiment 1. Therefore, they will not be elaborated herein. Each unit module can be implemented in whole or in part by software, hardware, or a combination thereof. Each unit module can be embedded in the processor of the computer device in hardware form or be independent of it, or be stored in the memory of the computer device in software form, so as to facilitate the processor to call and execute the operations corresponding to each of the above unit modules.

[0054] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered that the scope described in this specification is covered.

[0055] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A flow control method for a flow channel in an engine, characterized in that: The method comprises: providing a control panel at the inlet of the engine air intake duct, and regulating the flow mode in the flow duct by means of the control panel; When the control plate is perpendicular to the incoming air flow, the air inlet is in a closed state to block the backflow and forward transmission of the high-temperature products generated by the combustion heat release, and to ensure the positive reflection of the pressure wave system at the closed end; When the control plate reciprocates and rotates along the rotating shaft, an equivalent Laval nozzle configuration is formed, and a high turbulence flow field is formed to enhance the mixing degree of reactants; When the control plate is parallel to the air flow, the air intake resistance is small, thereby achieving low-resistance and fast air intake; When the control plate reciprocates along the rotating shaft, the angle when the control plate is perpendicular to the air flow is regarded as 0°, and the angle when the control plate is parallel to the air flow is regarded as 90°, and the reciprocating rotation of the control plate along 0°~90° is one cycle; The control plate has a critical angle within one rotation cycle along the rotation axis; When the incoming air flow is subsonic and the control plate rotates to between 0° and the critical angle, the subsonic incoming flow is accelerated through the equivalent Laval nozzle configuration to form a sonic throat, and a local supersonic flow field area and a subsonic flow field area are formed behind the control plate. When the control plate rotates to between the critical angle and 90°, the subsonic incoming flow remains subsonic at the throat, and a subsonic flow field area is formed after the throat.

2. The flow control method of the flow passage in the engine according to claim 1, characterized in that: When the incoming air flow is a supersonic flow, the supersonic flow is decelerated through the equivalent Laval nozzle configuration to form a sonic throat, and a local supersonic flow field area and a subsonic flow field area are formed behind the control plate.

3. The flow control method of the flow passage in the engine according to claim 1, characterized in that: When the control plate reciprocates along the rotating shaft, the rotating end of the control plate induces an unsteady flow field and forms an unsteady strong turbulence flow field near the fuel injection area, thereby enhancing the mixing of reactants.

4. The flow control method of the flow passage in the engine according to claim 3, characterized in that: When the control plate reciprocates and rotates along the rotating shaft, a normal shock wave is generated downstream of the flow channel in the engine; The positive shock wave meets the fuel in the fuel injection area, further enhancing the mixing of the reactants to form nearly premixed explosive combustion gas.

5. The flow control method of the flow passage in the engine according to claim 1, characterized in that: The invention is applied to a flow control device of an internal flow channel of an engine, and the device comprises: a control plate arranged at the entrance of the air inlet channel, one end of the control plate is fixed to the inner wall surface of the air inlet channel through a rotating shaft, and the other end is a rotating end; the rotating end has a stroke of reciprocating rotation motion centered on the rotating shaft.

6. The flow control method of the flow passage in the engine according to claim 5, characterized in that: The rotating end of the control plate performs periodic reciprocating rotational motion, with one reciprocating rotation from 0° to 90° constituting one cycle.

7. The flow control method of the flow passage in the engine according to claim 6, characterized in that: The rotating shaft is driven to rotate by a driving member, thereby driving the control plate to reciprocate and rotate.

8. The flow control method of a flow passage in an engine according to claim 6 or 7, characterized in that: The shape of the control plate is matched to the cross-sectional shape at the inlet of the air inlet, so that when the control plate is arranged perpendicular to the incoming air flow, the air inlet can be in a closed state.

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