CN-122020863-A - Method and system for analyzing bird strike impact load of front edge of aero-engine blade

CN122020863ACN 122020863 ACN122020863 ACN 122020863ACN-122020863-A

Abstract

The invention relates to the technical field of bird strike resistant design of aero-engine blades, and discloses a method and a system for analyzing bird strike impact load at the front edge of the aero-engine blade, wherein the method is used for rapidly analyzing and obtaining the impact load of bird strike at the front edge of the blade by comprehensively considering attribute parameters of a bird body model, structural parameters of the engine and state parameters under an examination working condition so as to replace the traditional finite element analysis method, compared with the traditional finite element analysis method, the method can obviously shorten the analysis period and reduce the cost, and can realize the rapid analysis of the impact load of multiple working conditions and multiple parts by adjusting the attribute parameters of the bird body model, the structural parameters of the engine and the state parameters under the examination working conditions, thereby providing powerful support for the design optimization and the safety evaluation of the aeroengine blade.

Inventors

ZHANG SHENZHI
HU BO
YANG ZONGZHI
ZHAO CHAOJUN
SHEN QINGYANG
HE YUN
WANG MEI

Assignees

中国航发四川燃气涡轮研究院

Dates

Publication Date: 20260512
Application Date: 20260414

Claims (10)

1. An aircraft engine blade leading edge bird strike impact load analysis method, comprising: Adopting a bird body model to perform bird strike simulation on the front edge of an aeroengine blade, and analyzing and obtaining the cutting-off time of the blade by the bird body model when the blade is struck by a bird, the maximum contact area of a bird block acting on the surface of the blade and the stagnation pressure of the bird block born by the impact point of the front edge of the blade and the bird body model according to the attribute parameters of the bird body model, the structural parameters of the engine and the state parameters of the engine under the examination working condition; Analyzing and obtaining peak impact force born by the blade in the process of cutting the bird body model according to the stagnation pressure of the bird block and the maximum contact area of the bird block; The product of the peak impact force born by the blade in the process of cutting the bird body model and the time when the bird body model is cut off by the blade is taken as the impact load of bird strike at the front edge of the blade.
2. The method of analyzing bird strike impact load on a leading edge of an aircraft engine blade according to claim 1, wherein the step of analyzing the time at which the bird body model is cut off by the blade when the blade bird strikes comprises: determining tangential linear velocity of the impact point of the front edge of the blade and the bird body model according to the rotating speed of the blade and the radius of the impact point of the front edge of the blade and the bird body model; and analyzing and obtaining the cutting time of the bird body model by the blade based on the tangential linear speed of the impact point of the front edge of the blade and the bird body model and the diameter of the bird body model.
3. The aircraft engine blade leading edge bird strike impact load analysis method of claim 2 wherein the time for which the bird body model is cut by the blade is determined by the following equation: ; Wherein: the time for cutting the bird body model by the blade; Is the diameter of the bird body model; is the tangential linear velocity of the impact point of the blade leading edge and the bird model.
4. A method of analyzing bird strike impact load on a leading edge of an aircraft engine blade according to claim 3, wherein the step of analyzing the maximum contact area of the bird's mass against the blade surface comprises: According to the tangential linear velocity of the impact point of the blade front edge and the bird body model and the axial velocity of the bird body model, analyzing and obtaining an included angle of the incidence direction of the bird body model relative to the axial direction of the engine; and analyzing and obtaining the maximum contact area of the bird block acting on the surface of the blade according to the diameter of the bird body model and the included angle of the incident direction of the bird body model relative to the axial direction of the engine.
5. The aircraft engine blade leading edge bird strike impact load analysis method of claim 4 wherein the maximum bird block contact area acting on the blade surface is determined by the formula: ; Wherein: Maximum contact area for bird pieces acting on the blade surface; is the included angle of the incidence direction of the bird model relative to the axial direction of the engine.
6. The method of analyzing bird strike impact load on a leading edge of an aircraft engine blade according to claim 5, wherein the step of analyzing bird block stagnation pressure received by the impact point of the leading edge of the blade with the bird body model comprises: According to the axial speed of the bird body model and the tangential linear speed of the impact point of the blade front edge and the bird body model, analyzing to obtain the relative speed of the bird block relative to the impact point of the blade front edge and the bird body model, and then analyzing to obtain the normal speed of the bird block relative to the chord direction of the blade front edge by combining the geometric air inlet angle of the blade front edge and the included angle of the incidence direction of the bird body model relative to the axial direction of the engine; And analyzing and obtaining the stagnation pressure of the bird block born by the impact point of the blade front edge and the bird body model according to the normal speed of the bird block relative to the chord direction of the blade front edge and the density of the bird body model.
7. The method of analyzing bird strike impact load on the leading edge of an aircraft engine blade according to claim 6, wherein the bird block stagnation pressure experienced by the point of impact of the leading edge of the blade with the bird body model is determined by the following equation: ; Wherein: Stagnation pressure of bird blocks born by impact points of the front edges of the blades and the bird body model; is the density of the bird body model; the axial velocity of the bird body model; Is the rotational speed of the blade; The radius of the impact point between the front edge of the blade and the bird model; is the geometric inlet angle of the leading edge of the blade.
8. The method of analyzing bird strike impact load on the leading edge of an aircraft engine blade according to claim 7, wherein the peak impact force experienced by the blade during cutting of the bird body model is determined by the following equation: ; Wherein: Peak impact forces experienced during cutting of the bird body model for the blade.
9. The aircraft engine blade leading edge bird strike impact load analysis method of claim 8, wherein the blade leading edge bird strike impact load is expressed as: ; Wherein: is the impact load of bird strike at the leading edge of the blade.
10. An aircraft engine blade leading edge bird strike impact load analysis system, realized based on the aircraft engine blade leading edge bird strike impact load analysis method of any one of claims 1-9, comprising: The bird strike simulation analysis module is used for carrying out bird strike simulation on the front edge of the blade of the aeroengine by adopting a bird body model, and analyzing and obtaining the cutting-off time of the blade of the bird body model when the blade is struck by the bird, the maximum contact area of a bird block acting on the surface of the blade, and the stagnation pressure of the bird block born by the impact point of the front edge of the blade and the bird body model according to the attribute parameters of the bird body model, the structural parameters of the engine and the state parameters of the engine under the examination working condition; The peak impact force analysis module is used for analyzing and obtaining peak impact force born by the blade in the process of cutting the bird body model according to the stagnation pressure of the bird block and the maximum contact area of the bird block; And the impact load analysis module is used for taking the product of the peak impact force born by the blade in the process of cutting the bird body model and the time when the bird body model is cut off by the blade as the impact load of bird strike at the front edge of the blade.

Description

Method and system for analyzing bird strike impact load of front edge of aero-engine blade Technical Field The invention relates to the technical field of bird strike resistant design of aero-engine blades, and discloses a method and a system for analyzing bird strike impact load at the front edge of an aero-engine blade. Background Aeronautical technology is rapidly developed, the number of bird strike events encountered by various aircraft is increased year by year, and the aircraft safety is seriously influenced, wherein the proportion of bird strikes encountered by an engine part is highest in all parts of the aircraft. After an aeroengine collides with birds, air inlet components such as fan blades and the like are extremely easy to generate impact damage, so that aerodynamic performance deterioration and dynamic response of the whole structure are caused, and the safety of the engine and even the aircraft is greatly threatened. In order to obtain higher thrust-weight ratio, one of the key technologies adopted by modern high-performance aeroengines is to improve the unit windward area flow and the stage pressure ratio of fan/compressor components and reduce the number of stages and blades on the premise of not reducing the stage efficiency, so that the structure tends to adopt structures such as thin-wall front edges, blisks and the like. The technology greatly improves the aerodynamic performance of the blade, reduces the bird strike resistance of the blade, and further causes the flight safety problem. Bird swallowing ability of an aeroengine is one of the key subjects of navigable approval, so that bird strike resistance design of modern high-performance engine blades is of great importance. The current bird strike resistant design of the engine blade is mainly carried out through three-dimensional finite element simulation analysis, although the precision is higher, the calculation cost is very high due to the extremely small time step required by a solver, meanwhile, due to the fact that the number of engine working conditions verified by national army standards or airworthiness requirements is large, certain qualitative stipulation parameters are larger interval values (such as the take-off speed can be between 50m/s and 150 m/s), and meanwhile, the impact part is only qualitatively stipulated as a key part, so that the cost calculated by adopting finite elements in the actual analysis is exponentially increased. Disclosure of Invention The invention aims to provide an analysis method and system for bird strike impact load of an aircraft engine blade front edge, which can improve the analysis efficiency of the impact load of the blade front edge bird strike, reduce the analysis period and cost, and facilitate the realization of multi-working-condition and multi-position calculation analysis. In order to achieve the technical effects, the technical scheme adopted by the invention is as follows: An aircraft engine blade leading edge bird strike impact load analysis method comprising: Adopting a bird body model to perform bird strike simulation on the front edge of an aeroengine blade, and analyzing and obtaining the cutting-off time of the blade by the bird body model when the blade is struck by a bird, the maximum contact area of a bird block acting on the surface of the blade and the stagnation pressure of the bird block born by the impact point of the front edge of the blade and the bird body model according to the attribute parameters of the bird body model, the structural parameters of the engine and the state parameters of the engine under the examination working condition; Analyzing and obtaining peak impact force born by the blade in the process of cutting the bird body model according to the stagnation pressure of the bird block and the maximum contact area of the bird block; The product of the peak impact force born by the blade in the process of cutting the bird body model and the time when the bird body model is cut off by the blade is taken as the impact load of bird strike at the front edge of the blade. Further, the step of analyzing the time when the bird body model is cut off by the blade when the blade bird strikes, includes: determining tangential linear velocity of the impact point of the front edge of the blade and the bird body model according to the rotating speed of the blade and the radius of the impact point of the front edge of the blade and the bird body model; and analyzing and obtaining the cutting time of the bird body model by the blade based on the tangential linear speed of the impact point of the front edge of the blade and the bird body model and the diameter of the bird body model. Further, the time for which the bird body model is cut off by the blade is determined by the following formula: ; Wherein: the time for cutting the bird body model by the blade; Is the diameter of the bird body model; is the tangential linear velocity of the impact point of the bla