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CN-122014688-A - Method for acquiring overspeed steady-state flow field of air compressor

CN122014688ACN 122014688 ACN122014688 ACN 122014688ACN-122014688-A

Abstract

The invention relates to the technical field of aircraft engine design, in particular to a method for acquiring an overspeed steady-state flow field of a gas compressor, which comprises the following steps of the gas compressor; the compressor comprises a rotor, a stator and an auxiliary body, wherein the stator is arranged at the downstream of the rotor, the auxiliary body is arranged at the downstream of the stator, the auxiliary body is disc-shaped, and the auxiliary body generates an auxiliary force field to provide pneumatic damping at a low flow point. The present disclosure may improve the aerodynamic damping of a compression system by introducing an auxiliary downstream of the compressor to inhibit flow instability.

Inventors

  • Pan tianyu
  • LI QIUSHI
  • Ling Jianlan
  • LIU SHIJIE
  • LI ZHIPING

Assignees

  • 北京航空航天大学

Dates

Publication Date
20260512
Application Date
20260209

Claims (10)

  1. 1. The method for acquiring the overspeed steady-state flow field of the gas compressor is characterized by comprising the gas compressor; the compressor comprises a rotor and a stator, wherein the stator is arranged at the downstream of the rotor; The compressor further comprises an auxiliary body, the auxiliary body is arranged at the downstream of the stator, the auxiliary body is disc-shaped, and the auxiliary body generates an auxiliary force field to provide pneumatic damping at a low flow point.
  2. 2. The method of claim 1, wherein the stator comprises at least two adjacent rows of blades to reduce the blade root load of the blades.
  3. 3. The method of claim 2 wherein said auxiliary body is spaced from said stator by a distance of 1.2 times the height of the second row of vanes of said stator.
  4. 4. The method of claim 1, wherein the auxiliary body has a dimension such that a radius is equal to a blade height of a second row of blades of the stator, and an axial thickness is equal to an axial thickness of the stator.
  5. 5. The method for acquiring a steady-state flow field of a overspeed exceeding of a compressor according to claim 1, wherein an auxiliary force domain function varying with flow is constructed to simulate pneumatic damping of the compressor, and the auxiliary force domain function is F=k (M Stall of -M) A; Wherein k is characteristic slope and is determined according to characteristic slope of near-blocking point of the compressor, M Stall of represents integral flow after stall of the compressor, M represents integral flow of the compressor, A is damping coefficient and is determined according to pneumatic damping of the compression system.
  6. 6. The method of claim 1, wherein the pressure ratio characteristic curve of the compressor after stall exhibits a positive slope at 65% of the maximum rotational speed of the rotor.
  7. 7. The method of claim 6, wherein the axial force of the rotor blade tips peaks first at 65% of maximum speed, indicating the presence of a localized stall zone.
  8. 8. The method of claim 6, wherein the axial force of the stator blade at a portion below 70% of the blade height peaks at 65% of the maximum rotational speed of the rotor.
  9. 9. The method of claim 1, wherein the maximum rotational speed of the compressor is 22000 rpm, the total pressure ratio is 1.6, and the maximum mass flow is 13.5 kg/s.
  10. 10. The method of claim 1, wherein the rotor has a number of blades of 17, a hub/tip ratio of 0.565, and an aspect ratio of 0.956; the number of adjacent blades of two rows of the stator is 29.

Description

Method for acquiring overspeed steady-state flow field of air compressor Technical Field The disclosure relates to the technical field of aircraft engine design, in particular to a method for acquiring an overspeed steady-state flow field of a gas compressor. Background The concept of the overspeed characteristics of the compressor is proposed when analyzing the stability problem of the compressor, and is used for describing the behavior of the compressor outside the stability boundary. Although the compressor has an internal flow field with circumferentially propagating stall clusters when the operating point is outside the stability boundary, the flow conditions inside the compressor are typically non-axisymmetric and non-steady when the operating point is outside the stability boundary. This non-axisymmetric, unsteady aerodynamic feature is broken down into a circumferentially uniform stable portion and a circumferentially non-uniform dynamic portion, which are modeled separately, and the overspeed characteristics of the compressor are used to describe the former. The overspeed characteristic of the compressor is artificially assumed to have a characteristic that is not time-dependent and axisymmetric in the model, and is therefore also referred to as axisymmetric pressure rise characteristic (Axisymmetric Pressure RISE CHARACTERISTIC). The stability of the compressor is closely related to the spatial distribution of the load, whereas the critical load in the local area plays a decisive role in the onset of flow instability. When a compressor with unknown characteristics is subjected to constant value simulation, the axisymmetry of the compressor cannot be directly obtained. Disclosure of Invention The present disclosure has been made in view of the above-described problems. The present disclosure provides a method for acquiring a compressor overspeed steady-state flow field. According to one aspect of the present disclosure, there is provided a method for acquiring a compressor overspeed steady-state flow field, including the steps of the compressor including a rotor and a stator, the stator being disposed downstream of the rotor; The compressor further comprises an auxiliary body, the auxiliary body is arranged at the downstream of the stator, the auxiliary body is disc-shaped, and the auxiliary body generates an auxiliary force field to provide pneumatic damping at a low flow point. In addition, according to a method for acquiring a compressor overspeed steady-state flow field in one aspect of the present disclosure, the stator at least comprises two rows of adjacent blades so as to reduce the blade root load of the blades. In addition, according to the method for acquiring the overspeed steady-state flow field of the compressor, the distance between the auxiliary body and the stator is 1.2 times of the blade height of the second row of blades of the stator. In addition, according to the method for acquiring the overspeed steady-state flow field of the compressor, the auxiliary body is in a size that the radius is the same as the blade height of the second row of blades of the stator, and the axial thickness is the same as the axial thickness of the stator. In addition, according to the method for acquiring the overspeed steady-state flow field of the compressor, an auxiliary force domain function which changes along with the flow is constructed to simulate the pneumatic damping of the compressor, wherein the auxiliary force domain function is F=k(M Stall of -M)A; Wherein k is characteristic slope and is determined according to characteristic slope of near-blocking point of the compressor, M Stall of represents integral flow after stall of the compressor, M represents integral flow of the compressor, A is damping coefficient and is determined according to pneumatic damping of the compression system. In addition, according to a method for acquiring a compressor overspeed steady-state flow field in one aspect of the disclosure, the pressure ratio characteristic curve of the compressor after stall presents a positive slope at the maximum rotation speed of the rotor of 65%. Furthermore, according to a method of acquiring a compressor overspeed steady-state flow field in one aspect of the present disclosure, the axial force of the blade tips of the rotor peaks first at 65% of the maximum rotational speed, indicating the presence of a localized stall zone. In addition, according to the method for acquiring the overspeed steady-state flow field of the compressor in one aspect of the disclosure, the axial force of the blade of the stator, which is positioned below 70% of the blade height, reaches a peak value at the maximum rotation speed of 65%. In addition, according to the method for acquiring the overspeed steady-state flow field of the compressor in one aspect of the disclosure, the maximum rotating speed of the compressor is 22000 rpm, the total pressure ratio is 1.6, and the maximum mass flow is 13.5