A blade with adaptive active control and its manufacturing method

Abstract

The present disclosure provides an adaptively actively controlled blade and a manufacturing method thereof. The blade includes a blade part and a control part, wherein: the blade part, the cross-section of the blade is crescent-shaped, the fluid side of the blade part is composed of two curved surfaces, and a jet channel (1) is included in the blade part. The jet channel (1) penetrates through the blade part and forms a suction surface jet slit (3) and a pressure surface jet slit (4). Among them, the outlet of the suction surface jet slit (3) corresponds to the suction surface Coanda surface (10), and the outlet of the pressure surface jet slit (4) corresponds to the pressure surface Coanda surface (11); the control part includes a first pressure sensor (5), a second pressure sensor (6) and a pressure valve (7). The pressure valve (7) controls the outlet air pressure of the jet channel (1) according to the pressures monitored by the first pressure sensor (5) and the second pressure sensor (6). On the other hand, the present disclosure also provides a method for manufacturing an adaptively actively controlled blade.

Description

Technical Field

[0001] The present invention relates to the field of flow control of impeller machinery such as compressors and turbines, and in particular to an adaptive active control blade and a manufacturing method thereof. Background Art

[0002] Flow separation is a complex fluid flow phenomenon that is commonly found in fluid machinery such as compressors and turbines. Its essence stems from the interaction between viscous flow and inviscid flow. The low-energy fluid caused by flow separation converges on the blade surface, hindering the flow of the mainstream fluid, causing blockage of the flow channel, and leading to a decrease in fluid machinery performance. When the flow separation is serious, the impeller machinery will enter unstable conditions such as rotational stall and surge, increase vibration, and sharply reduce efficiency, and even cause serious accidents. Therefore, it is of great significance to try to suppress flow separation in impeller machinery.

[0003] In this context, researchers at home and abroad have studied a variety of flow control methods to control the flow separation on the blade surface in order to improve the efficiency of the impeller machinery and expand the working range. The existing flow control methods are mainly divided into two categories: active control and passive control. Among them, passive control does not require external energy, and only controls the flow of gas by changing the original structure of fluid machinery such as compressors and turbines, or adding small structures. However, when the flow state changes, the passive control scheme may not adapt to the aerodynamic performance of the impeller machinery under the flow state, but may deteriorate the performance; active control is to detect the operating state of the impeller machinery equipment, and then control the flow separation through the adjustment mechanism. It requires external energy, but the control effect is obvious. In recent years, active control technology has gradually matured, and compared with passive control technology, it has higher flexibility and has attracted the attention of more and more researchers.

[0004] In response to the surface separation phenomenon of blades, there have been many studies on boundary layer jet technology in active control technology and relatively ideal results have been achieved. Therefore, boundary layer jet technology has become one of the most promising measures to improve the efficiency and stability of fluid machinery. The Coanda jet technology based on the Coanda effect is a new application form of boundary layer jet technology. The difference between it and conventional boundary layer jet technology is that the application of this technology requires a Coanda surface with a certain curvature to be constructed on the trailing edge of the blade.

[0005] When the blade attack angle is large, flow separation generally exists on the suction side of the blade, while when the blade operates at a smaller attack angle or even a negative attack angle, separation will mainly exist on the pressure side of the blade. The separation technology in the prior art mostly considers the flow separation under conventional flow attack angles, and most of them are flow separation on the suction side of the blade at a positive attack angle. In the actual operation of the impeller machinery, changes in operating conditions will lead to changes in the airflow attack angle. Therefore, the prior art is not applicable to all attack angle ranges in the actual operation of the impeller machinery. Summary of the Invention

[0006] (I) Technical Problem to be Solved

[0007] The present invention provides an adaptively actively controlled blade and a manufacturing method thereof, which solves at least the above technical problems.

[0008] (II) Technical Solution

[0009] The present invention provides an adaptively actively controlled blade, including a blade part and a control part, wherein:

[0010] The blade part, the cross-section of the blade is crescent-shaped, the fluid side of the blade part is composed of two curved surfaces, and a jet channel 1 is included in the blade part. The jet channel 1 penetrates the blade part and forms a suction surface jet slit 3 and a pressure surface jet slit 4. Among them, the outlet of the suction surface jet slit 3 corresponds to the suction surface Coanda surface 10, and the outlet of the pressure surface jet slit 4 corresponds to the pressure surface Coanda surface 11; the control part includes a first pressure sensor 5, a second pressure sensor 6 and a pressure valve 7. Among them, the first pressure sensor 5 is arranged at the outlet of the suction surface jet slit 3 for monitoring the pressure at the outlet of the suction surface jet slit 3; the second pressure sensor 6 is arranged at the outlet of the pressure surface jet slit 4 for monitoring the pressure at the outlet of the second jet slit 4, and the pressure valve 7 controls the outlet pressure of the jet channel 1 according to the pressures monitored by the first pressure sensor 5 and the second pressure sensor 6.

[0011] Optionally, it further includes: a detector 8, which is connected to the first pressure sensor 5 and the second pressure sensor 6 for detecting the pressure values at the first pressure sensor 5 and the second pressure sensor 6; a driver 9, which is connected to the detector 8 and the pressure valve 7 for setting the pressure at the pressure valve 7 according to the pressure values in the detector 8.

[0012] Optionally, the jet channel 1 is an arc-shaped groove.

[0013] Optionally, at least one guide vane 12 is arranged in the jet channel 1.

[0014] Optionally, the height of the jet channel 1 remains unchanged along the blade height direction.

[0015] Optionally, one end face of the jet channel 1 is connected to a jet gas source.

[0016] Optionally, the slit heights of the suction surface jet slit 3 and the pressure surface jet slit 4 remain unchanged along the blade height direction.

[0017] Optionally, the pressure surface Coanda surface 10 and the pressure surface Coanda surface 11 are respectively tangent to the fluid side of the blade part by two curved surfaces.

[0018] Optionally, the ratio of the height of the suction surface jet slot 3 to the radius of the suction surface Coanda surface 10 is less than 0.1, and the ratio of the height of the pressure surface jet slot 4 to the radius of the pressure surface Coanda surface 11 is less than 0.1.

[0019] On the other hand, the present invention also provides a method for manufacturing a blade with adaptive active control, and the steps include: S1, determining the position of fluid separation of the original blade; S2, arranging a jet channel 1 at the position of fluid separation of the original blade, the jet channel 1 penetrating through both surfaces on the pressure fluid side and forming a suction surface jet slot 3 and a pressure surface jet slot 4; S3, respectively installing a first pressure sensor 5 and the second pressure sensor 6 at the suction surface jet slot 3 and the pressure surface jet slot 4, and installing a pressure valve 7 at the outlet of the jet channel 1.

[0020] (III) Beneficial effects

[0021] By opening two through jet slots on the blade surface and arranging a pressure detection and control device, the present invention enables the pressure in the jet slots to always maintain the pressure value with a larger pressure at the outlet of the jet slots, so that the gas in the jet slots is ejected from the jet slot with a smaller pressure, and then passes through a curved surface with a certain curvature. Due to the Coanda effect, the jet flows along the curved surface, increasing the fluid kinetic energy of the blade boundary layer and reducing flow separation. Description of the drawings

[0022] Figure 1 Schematically shows a structural diagram of a blade part of an embodiment of the present disclosure.

[0023] Figure 2 Schematically shows a structural diagram of a guide vane of an embodiment of the present disclosure.

[0024] Figure 3 Schematically shows a structural diagram of a control part of an embodiment of the present disclosure.

[0025] Figure 4 Schematically shows a manufacturing method of the blade of an embodiment of the present disclosure. Detailed implementation manners

[0026] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to specific embodiments and the accompanying drawings.

[0027] Some embodiments of the present disclosure will be described more comprehensively hereinafter with reference to the accompanying drawings, and some but not all of the embodiments will be shown. In fact, the various embodiments of the present disclosure can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure meets the applicable legal requirements.

[0028] An embodiment of the present invention provides a blade with adaptive active control based on the Coanda effect, including a blade part and a control part.

[0029] Figure 1 Schematically shows a structural schematic diagram of the blade part of the present disclosure embodiment. It can be seen that the cross-section of the blade part is crescent-shaped, where: Figure 1 It can be seen that the cross-section of the blade part is crescent-shaped, where:

[0030] The fluid side of the blade part consists of two curved surfaces, forming the convex surface and the concave surface of the blade part; the terminal cross-section of the blade part in the fluid direction is provided with a jet channel 1 for gas passage. The jet channel 1 penetrates the entire blade and forms a suction surface jet slit 3 and a pressure surface jet slit 4 on the blade surface. The suction surface jet slit 3 is located on the convex surface of the blade, and the pressure surface jet slit 4 is located on the concave surface of the blade. And the surfaces after the outlets of the suction surface jet slit 3 and the pressure surface jet slit 4 are respectively the suction surface Coanda surface 10 and the pressure surface Coanda surface 11, and the curvatures of the suction surface Coanda surface 10 and the pressure surface Coanda surface 11 are respectively greater than the curvatures of the blade part upstream of the outlets of the suction surface jet slit 3 and the pressure surface jet slit 4.

[0031] In this embodiment, it is necessary to first determine the starting position of fluid separation. Determine the starting position of fluid separation in the blade part through experiments or simulations, etc. The pressure surface jet slit is located at the starting position of pressure surface separation, and the suction surface jet slit is located at the starting position of suction surface separation. A jet channel 1 is opened between the pressure surface jet slit and the suction surface jet slit. The jet channel 1 penetrates the entire blade. For the convenience of description, the blade part after the jet slit is called the tail blade, and the blade part upstream of the jet slit is called the front blade. The outlets of the suction surface jet slit 3 and the pressure surface jet slit 4 are respectively two convex surfaces with the Coanda effect, namely the suction surface Coanda surface 10 and the pressure surface Coanda surface 11. The two Coanda surfaces are connected by an arc surface, and the arc surface is located in the jet channel 1 and does not completely fit with the jet channel 1, that is, the above-mentioned suction surface jet slit 3 and pressure surface jet slit 4 are formed. The curvatures of the two Coanda surfaces of the tail blade are both greater than the curvature of the original blade at this place before treatment, and it is necessary to ensure that the terminals of the convex surface and the concave surface of the front blade at the outlet of the jet slit are respectively tangent to the two Coanda surfaces, which can effectively avoid the mixing loss caused by the jet being inconsistent with the mainstream direction. The ratio of the slit height of the suction surface jet slit 3 to the radius of the suction surface Coanda surface 10 is less than 0.1, and the ratio of the slit height of the pressure surface jet slit 4 to the radius of the pressure surface Coanda surface 11 is less than 0.1; as much as possible to make the slit height of the jet slit as small as possible under the condition allowed by machining, so that the jet air flow velocity is greater. To ensure that the jet flow is as uniform as possible in the blade height direction, the width of the arc-shaped groove remains unchanged along the blade height direction, and then the heights of the suction surface jet slit 3 and the pressure surface jet slit 4 remain unchanged along the blade height direction. The total blade chord length of the processed blade part is preferably the same as the chord length of the original blade.

[0032] The jet passage 1 is connected to a jet gas source, which can be provided by an external gas source, such as the bleed air from the high-pressure stage of an axial compressor, etc. In practical applications, in order to make the airflow more uniform and obtain better fluid performance, several flow guiding vanes 12 can be installed in the jet passage 1 (such as Figure 2 shown), by optimizing the structure and position of the flow guiding vanes 12, the jet can be turned in the jet passage 1, and after being reorganized, it flows out at a uniform speed in the same direction as the fluid on the surface of the vane body 1.

[0033] Figure 3 Schematically shows the structural schematic diagram of the control part of the embodiment of the present disclosure. As can be seen from Figure 3 , the control part includes a first pressure sensor 5, a second pressure sensor 6, a pressure valve 7, a detector 8 and a driver 9. Among them, the first pressure sensor 5 and the second pressure sensor 6 are respectively located at the outlets of the suction surface jet slot 3 and the pressure surface jet slot 4, and are respectively used to detect the pressures P ss and P ps at the suction surface jet slot 3 and the pressure surface jet slot 4. The detector 8 is connected to the suction surface jet slot 3, the pressure surface jet slot 4 and the driver 9. The detector 8 constantly detects the pressures at the outlets of the suction surface jet slot 3 and the pressure surface jet slot 4, that is, P ss and P ps , compares the pressure values at the outlets of the two jet slots, and sends the larger value to the driver 9, that is, P 0 =max{P ss , P ps}. The driver 9 is connected to the pressure valve 7 below. The driver 9 sets the pressure P 0 of the pressure valve 7 to this pressure value, so that the pressure in the jet passage 1 always remains the larger value of the pressures at the outlets of the two jet slots, and further makes the gas in the jet passage 1 spray out from the jet slot with the smaller pressure. Due to the Coanda effect, after the gas sprays out from the jet slot, it will flow along the convex surface of the blade sub-body 2 and then attach to the wall, thereby increasing the fluid kinetic energy of the boundary layer and improving the flow separation situation on the blade surface.

[0034] Figure 4 Schematically shows the manufacturing method of the blade of the embodiment of the present disclosure, which specifically includes:

[0035] S1, determining the position of fluid separation of the original blade;

[0036] Conduct experiments or numerical simulations on the original blade to determine the position where fluid separation occurs on the blade surface under normal operating conditions, and then reconstruct the blade downstream of the separation point.

[0037] S2. Set up the jet channel 1 at the position where fluid separation occurs on the original blade. This jet channel 1 penetrates through both surfaces on the pressure fluid side and forms a suction surface jet slit 3 and a pressure surface jet slit 4.

[0038] Set up the jet channel 1 near the separation point of the original blade. This jet channel 1 is used for the jet flow path. And to ensure uniform jetting, the height of the jet channel 1 in the blade cross-section remains unchanged along the blade height direction. Trim the mouth of the jet channel 1 and the blade surface so that the surface of the jet channel 1 and the blade surface have a circular arc transition. And this jet channel 1 divides the original blade into a front blade and a tail blade. Process the tail blade. The two surfaces on the fluid side of the tail of the original blade are respectively a convex surface and a concave surface. Process them. Make the curvature of a part of the convex surface larger to form a suction surface Coanda surface 10, and make a part of the concave surface into a convex surface to form a pressure surface Coanda surface 11.

[0039] It should be noted that the curvature of the blade surface affects the effect of flow control. If the curvature is too small, the turning ability of the airflow with the increased wall attachment effect decreases. If the curvature is too large, the airflow wall attachment time is too short and separation is likely to occur. Therefore, when manufacturing, the curvature of the suction surface Coanda surface 10 and the pressure surface Coanda surface 11 should be comprehensively considered, and it should be ensured that the curvature at the starting point of the suction surface Coanda surface 10 is consistent with the terminal curvature of the fluid side surface of the rear blade. On the one hand, it makes the direction of the main fluid and the direction of the airflow ejected from the jet slit consistent, reducing the mixing energy loss. On the other hand, it can ensure the curvature continuity of the front blade and the tail blade.

[0040] Install part of the surface of the tail blade inside the jet channel 1, and form a suction surface jet slit 3 and a pressure surface jet slit 4 with the jet channel 1. The slit height of the jet slit should be as small as possible to increase the velocity of the ejected airflow. The total chord length of the adjusted blade should be kept as equal as possible to the total chord length of the original blade, so that the aerodynamic performance of the adjusted blade can be the same as or better than that of the original blade when the jet volume is 0. At a relatively small jet volume, such as within 2% of the main steam flow rate, it can effectively suppress flow separation, thereby improving the efficiency and stability of the turbomachine.

[0041] S3. Install the first pressure sensor 5 and the second pressure sensor 6 at the suction surface jet slit 3 and the pressure surface jet slit 4 respectively, and install a control valve 7 at the outlet of the jet channel 1.

[0042] A first pressure sensor 5 and a second pressure sensor 6 are respectively installed at the outlets of the suction surface jet slot 3 and the pressure surface jet slot 4 to detect the pressure at the jet slots. The detector 8 is connected to the suction surface jet slot 3, the pressure surface jet slot 4, and the driver 9. The detector 8 constantly detects the pressures at the outlets of the suction surface jet slot 3 and the pressure surface jet slot 4, compares the pressure values at the outlets of the two jet slots, and sends the larger value to the driver 9. The driver 9 is connected to the pressure valve 7 below, and the driver 9 sets the pressure of the pressure valve 7 to this pressure value, so that the pressure in the jet channel 1 always remains the larger value of the pressures at the outlets of the two jet slots, and further enables the gas in the jet channel 1 to be ejected from the jet slot with the smaller pressure. Due to the Coanda effect, after the gas is ejected from the jet slot and flows along the convex surface of the trailing blade, it will flow along the wall, thereby increasing the fluid kinetic energy of the boundary layer.

[0043] In addition, for the present disclosure, based on the two-dimensional design of the blade, the blade can be three-dimensionally designed for different impeller machines or different working conditions. The generation method of such a blade is not limited to the method in the present disclosure only. Any structure that can obtain the present disclosure is within the protection scope of the present disclosure. And the application scope of the blade of the present disclosure is not limited to the compressor only. Similar blades in any fluid machinery are within the protection scope of the present disclosure. The position and structure of the jet slot can be selected according to the blade structure and the flow condition.

[0044] So far, the embodiments of the present disclosure have been described in detail with reference to the drawings. It should be noted that in the drawings or the text of the specification, the implementation manners that are not depicted or described are all forms known to those of ordinary skill in the art and have not been described in detail. In addition, the definitions of the above-mentioned various elements and methods are not limited to the specific structures, shapes, or manners mentioned in the embodiments only. Those of ordinary skill in the art can make simple changes or replacements to them.

[0045] Based on the above description, those skilled in the art should have a clear understanding of the blade with adaptive active control of the present disclosure.

[0046] In summary, the present disclosure provides a blade with adaptive active control and a manufacturing method thereof. The blade adopts an active control mechanism and combines the Coanda effect to effectively suppress the phenomenon of flow separation commonly existing in impeller machines, avoid the occurrence of surging and stall, and effectively improve the efficiency and stability of compressors, turbines, and even the entire aeroengine, and has good prospects for popularization and application.

[0047] It should also be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "rear", "left", "right", etc., are only references to the directions in the accompanying drawings and are not used to limit the protection scope of the present disclosure. Throughout the drawings, the same elements are denoted by the same or similar reference numerals. When it may cause confusion in the understanding of the present disclosure, the conventional structures or configurations will be omitted.

[0048] Moreover, the shapes and sizes of the components in the figures do not reflect the actual sizes and proportions, but only illustrate the content of the embodiments of the present disclosure. Additionally, in the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0049] Unless otherwise known to the contrary, the numerical parameters in this specification and the appended claims are approximate values and can be changed according to the required characteristics obtained through the content of the present disclosure. Specifically, all the numbers representing the contents of the components, reaction conditions, etc. used in the specification and the claims should be understood to be modified by the term "about" in all cases. Generally, the meaning expressed is that it includes a change of ±10% in some embodiments, a change of ±5% in some embodiments, a change of ±1% in some embodiments, and a change of ±0.5% in some embodiments for a specific quantity.

[0050] Furthermore, the word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0051] The ordinal numbers such as "first", "second", "third", etc. used in the specification and the claims are used to modify the corresponding elements, and do not themselves mean that the element has any ordinal number, nor do they represent the order of one element and another element or the order in the manufacturing method. The use of these ordinal numbers is only to clearly distinguish an element with a certain name from another element with the same name.

[0052] In addition, unless specifically described or steps that must occur in sequence, the order of the above steps is not limited to those listed above and can be changed or rearranged according to the required design. And the above embodiments can be used in combination with each other or combined with other embodiments based on considerations of design and reliability, that is, the technical features in different embodiments can be freely combined to form more embodiments.

[0053] Similarly, it should be understood that, for the purpose of streamlining the present disclosure and facilitating the understanding of one or more of the various disclosed aspects, in the foregoing description of the exemplary embodiments of the present disclosure, the various features of the present disclosure are sometimes grouped together into a single embodiment, figure, or description thereof. However, the disclosed method should not be construed as reflecting an intention that the claimed present disclosure requires more features than are expressly recited in each claim. Rather, as reflected in the following claims, the disclosed aspects lie in less than all the features of the single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate embodiment of the present disclosure.

[0054] The foregoing specific embodiments have further elaborated on the object, technical solution, and beneficial effects of the present invention. It should be understood that the foregoing is only the specific embodiments of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A blade with adaptive active control, comprising a blade part and a control part, wherein: Blade part, the cross-section of the blade is crescent-shaped. The fluid side of the blade part consists of two curved surfaces. The blade part contains a jet channel (1), and the jet channel (1) penetrates through the blade part and forms a suction surface jet slit (3) and a pressure surface jet slit (4). Among them, the outlet of the suction surface jet slit (3) corresponds to the suction surface Coanda surface (10), and the outlet of the pressure surface jet slit (4) corresponds to the pressure surface Coanda surface (11); Control part, including a first pressure sensor (5), a second pressure sensor (6), a pressure valve (7), a detector (8) and a driver (9). Among them, the first pressure sensor (5) is arranged at the outlet of the suction surface jet slit (3) to monitor the pressure at the outlet of the suction surface jet slit (3); the second pressure sensor (6) is arranged at the outlet of the pressure surface jet slit (4) to monitor the pressure at the outlet of the pressure surface jet slit (4). The pressure valve (7) controls the outlet pressure of the jet channel (1) according to the pressures monitored by the first pressure sensor (5) and the second pressure sensor (6). The detector (8) is connected to the suction surface jet slit (3), the pressure surface jet slit (4) and the driver (9). The detector (8) constantly detects the pressures at the outlets of the suction surface jet slit (3) and the pressure surface jet slit (4), compares the pressure values at the outlets of the two jet slits, and sends the larger value to the driver (9). The driver (9) is connected to the pressure valve (7) below, so that the pressure in the jet channel (1) always remains the larger value of the pressures at the outlets of the two jet slits, and further enables the gas in the jet channel (1) to be ejected from the jet slit with a smaller pressure.

2. The blade according to claim 1, wherein: The detector (8) is connected to the first pressure sensor (5) and the second pressure sensor (6) to detect the pressure values at the first pressure sensor (5) and the second pressure sensor (6); The driver (9) is connected to the detector (8) and the pressure valve (7) to set the pressure at the pressure valve (7) according to the pressure value in the detector (8).

3. The blade according to claim 1, wherein, The jet channel (1) is an arc-shaped groove.

4. The blade according to claim 3, wherein, At least one guide vane (12) is arranged in the jet channel (1).

5. The blade according to claim 3, wherein, The height of the jet channel (1) remains unchanged along the blade height direction.

6. The blade according to claim 5, wherein, One side end face of the jet channel (1) is connected to a jet gas source.

7. The blade according to claim 1, wherein, The slit heights of the suction surface jet slit (3) and the pressure surface jet slit (4) remain unchanged along the blade height direction.

8. The blade according to claim 1, wherein, The suction surface Coanda surface (10) and the pressure surface Coanda surface (11) are respectively tangent to the fluid side of the blade part by two curved surfaces.

9. The blade according to claim 1, wherein, the ratio of the slot height of the suction surface jet slot (3) to the radius of the suction surface Coanda surface (10) is less than 0.1, and the ratio of the slot height of the pressure surface jet slot (4) to the radius of the pressure surface Coanda surface (11) is less than 0.

1.

10. A manufacturing method of the blade with adaptive active control according to any one of claims 1 to 9, the steps include: S1, determining the position of fluid separation of the original blade; S2, arranging a jet channel (1) at the position of fluid separation of the original blade, the jet channel (1) penetrates through the two surfaces on the pressure fluid side, and forms a suction surface jet slot (3) and a pressure surface jet slot (4); S3, respectively installing a first pressure sensor (5) and the second pressure sensor (6) at the suction surface jet slot (3) and the pressure surface jet slot (4), and installing a pressure valve (7) at the outlet of the jet channel (1).

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