A shaped passage diffuser structure for suppressing outlet wake vortex

Abstract

This invention relates to a conformal channel diffuser structure for suppressing outlet wake vortices. The diffuser body has an outlet end face with a circumferentially arrayed geometric structure that is rounded to create a smooth-transition outlet shape, thereby suppressing wake vortex flow at the outlet. This invention features a simple structure, is easy to manufacture, effectively improves diffuser efficiency, and enhances intake conditions in the downstream combustion chamber. It is suitable for centrifugal compressor components in micro-turbine engines.

Description

Technical Field

[0001] This invention belongs to the field of micro turbojet compressor technology, specifically relating to a conformal channel diffuser structure for suppressing exit wake vortices. It is applicable to centrifugal compressor components in micro turbine engines, and is particularly suitable for structural improvements that enhance diffuser outlet airflow characteristics and reduce flow losses. Background Technology

[0002] In recent decades, small / micro unmanned aerial vehicles (UAVs) and various light / micro aircraft have been widely used and rapidly developed. Micro turbine engines, due to their small size and low Reynolds number, suffer from low efficiency of individual components, resulting in overall poor performance. Furthermore, the compact structure and close proximity of components in micro turbine engines lead to significant aerodynamic and thermal influences during operation, further degrading overall engine performance. The centrifugal compressor, a compression component in micro turbine engines, consists of a centrifugal impeller and a diffuser. Research has found that diffuser-generated losses account for up to 30% of centrifugal compressor stage losses; therefore, diffuser performance significantly impacts the pressure ratio, efficiency, and stable operating range of the centrifugal compressor stage. Additionally, the diffuser outlet airflow, acting as the inlet condition for the downstream combustion chamber, also significantly affects the combustion chamber itself. Summary of the Invention

[0003] This invention provides a conformal channel diffuser structure for suppressing outlet wake vortices, thereby suppressing the phenomenon of wake vortex flow of gas at the diffuser outlet and reducing flow losses.

[0004] To solve the above technical problems, the present invention provides 1. a conformal channel diffuser structure for suppressing outlet wake vortices, comprising a diffuser body, characterized in that: the outlet end face of the diffuser body extends in a circumferential array geometric structure, and the extended structure is rounded to form a smoothly transitioned outlet shape, so as to suppress the wake vortex flow of gas at the outlet.

[0005] Furthermore, the length of the extension structure is 5mm to 15mm.

[0006] Furthermore, the length of the extension structure is 10 mm.

[0007] Furthermore, the radius of the rounded corners is 1mm to 3mm.

[0008] Furthermore, the extension structures are arranged in a uniform array along the circumference of the diffuser outlet.

[0009] Furthermore, centrifugal compressors are suitable for micro turbine engines.

[0010] Furthermore, the extension structure and the diffuser body are integrally formed.

[0011] Furthermore, the cross-sectional shape of the extension structure matches the cross-sectional shape of the diffuser outlet.

[0012] Furthermore, the rounded surface of the structure is smooth, without sharp corners or abrupt changes.

[0013] Furthermore, numerical simulations have verified that the diffuser outlet structure exhibits a wake vortex intensity that is more than 20% lower than that of the unmodified structure.

[0014] Beneficial Effects: Based on a conformal channel diffuser, this invention extends and rounds the diffuser outlet geometry to form a conformal channel diffuser outlet structure, thereby improving the phenomenon of wake vortex flow loss at the diffuser outlet. This invention aims to modify the outlet structure of the conformal channel diffuser to suppress the phenomenon of wake vortex flow at the diffuser outlet, thus reducing flow losses.

[0015] This invention has a simple structure and is easy to manufacture. It can effectively improve diffuser efficiency and improve the intake conditions of the downstream combustion chamber. It is suitable for centrifugal compressor components of micro turbine engines. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of an existing conformal channel-type wake vortex generation structure.

[0017] Figure 2 This is a schematic diagram of the rounded outlet structure of the conformal channel diffuser according to an embodiment of the present invention.

[0018] Figure 3 The computational fluid dynamics described in this embodiment of the invention captures the wake vortex flow phenomenon at the outlet of a conformal channel diffuser.

[0019] Explanation of reference numerals in the attached figures: 1-Location of wake vortex generation in conformal channel diffuser; 2-Rounded structure at outlet of conformal channel diffuser; 3-Wake vortex phenomenon at diffuser outlet. Detailed Implementation

[0020] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below.

[0021] The present invention proposes a conformal channel diffuser structure for suppressing outlet wake vortices. Based on the conformal channel diffuser, the diffuser outlet surface is extended with a circumferential array geometry and rounded at the end to form a smooth transition outlet shape, thereby suppressing the wake vortex flow of gas at the outlet and reducing flow losses.

[0022] like Figure 1As shown, traditional conformal channel diffusers are prone to wake vortex flow (as shown in label 3) at the outlet due to geometric abrupt changes, leading to flow separation and energy loss.

[0023] Will Figure 1 In a certain engineering project, the outlet surface of a conformal channel diffuser is extended with a circumferential array geometry, and the edges on both sides of the flow channel are rounded to form... Figure 2 The geometric structure.

[0024] This invention proposes an improved structure that extends the diffuser outlet end face circumferentially by 10 mm and rounds the extended portion to form a smoothly transitioned outlet shape (as shown by reference numeral 2). This structure can effectively guide the airflow to flow out smoothly, avoid flow separation, and suppress wake vortex flow losses.

[0025] Computational fluid dynamics simulations have verified that the improved diffuser outlet wake vortex intensity is significantly reduced, flow losses are decreased, and diffuser efficiency is improved by more than 5%.

[0026] The present invention has a simple structure, is easy to manufacture, and is applicable to the structural improvement of centrifugal compressor diffusers for various micro turbine engines.

[0027] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A conformal channel diffuser structure for suppressing exit wake vortices, comprising a diffuser body, characterized in that: The outlet end face of the diffuser body extends in a circumferential array geometric structure, and the extended structure is rounded to form a smooth transition outlet shape, so as to suppress the wake vortex flow of gas at the outlet.

2. The conformal channel diffuser structure for suppressing exit wake vortices according to claim 1, characterized in that: The length of the extension structure is 5mm to 15mm.

3. The conformal channel diffuser structure for suppressing exit wake vortices according to claim 2, characterized in that: The length of the extension structure is 10 mm.

4. The conformal channel diffuser structure for suppressing exit wake vortices according to claim 1, characterized in that: The radius of the rounded corners is 1mm to 3mm.

5. The conformal channel diffuser structure for suppressing exit wake vortices according to claim 1, characterized in that: The extension structures are arranged in a uniform array along the circumference of the diffuser outlet.

6. The conformal channel diffuser structure for suppressing exit wake vortices according to claim 1, characterized in that: Centrifugal compressor suitable for micro turbine engines.

7. The conformal channel diffuser structure for suppressing exit wake vortices according to claim 1, characterized in that: The extension structure is integrally formed with the diffuser body.

8. The conformal channel diffuser structure for suppressing exit wake vortices according to claim 1, characterized in that: The cross-sectional shape of the extension structure matches the cross-sectional shape of the diffuser outlet.

9. The conformal channel diffuser structure for suppressing exit wake vortices according to claim 1, characterized in that: The rounded surface of the structure is smooth, without sharp corners or abrupt changes.

10. The conformal channel diffuser structure for suppressing exit wake vortices according to claim 1, characterized in that: The diffuser outlet structure was verified through numerical simulation, and its wake vortex intensity was reduced by more than 20% compared with the unimproved structure.

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