Optimization Design Of Aeroengine High Pressure Compressor Blade Under Multi Physical Field Coupling

High pressure compressor is an important part of aeroengine,its performance has an important impact on engine performance.Supercharging ratio,aerodynamic efficiency,weight and working reliability are the main indicators to measure the performance of high-pressure compressor.The structural design of high-pressure compressor blade for these indicators plays an important role in improving the performance of aeroengine.The structural design of high-pressure compressor blade is a highly complex process of multidisciplinary coupling,which involves many aspects,such as parametric modeling,multi physical field coupling analysis,design optimization modeling and solving.How to establish a highly accurate and efficient performance evaluation model and optimization design method are the core contents of high-pressure compressor blade structural design.This thesis focuses on how to improve the efficiency of multi physical field analysis and the accuracy of multi-disciplinary design optimization modeling,establish the weight minimization structural design optimization model of high-pressure compressor blade under the coupling of multi physical fields,and propose a design optimization strategy of high-pressure compressor blade considering fatigue life constraints.The important work of thesis is divided into the following four parts:（1）Three-dimensional（3D）parametric modeling for high-pressure compressor blade based on non-uniform rational B-spline（NURBS）.3D parametric modeling with high precision is a key step to improve the efficiency of multi physical field analysis for compressor blade.Therefore,this paper studies how to realize the 3D parametric modeling of compressor blade.Firstly,the key parameters of blade profile design are determined according to the design requirements.Then,a parametric modeling method of blade plane cascade based on the inverse calculation principle of NURBS curve is proposed.In order to further improve the efficiency of this modeling method,BP（back propagation）neural network regression analysis model is introduced to fit the height of plane cascade,so as to realize the 3D parametric modeling of high-pressure compressor blade with high efficiency and high precision.（2）Fatigue life evaluation and vibration response analysis of high pressure compressor blades under multi physical field coupling.Multi physical field coupling is an inherent feature of the working environment for high-pressure compressor.Fatigue life and vibration response are two key indexes in the design of high-pressure compressor blade.In this thesis,firstly,taking rotor 37 compressor blade as the research object,the thermal solid fluid multi physical field coupling simulation analysis of compressor blade is completed,and its aerodynamic characteristics and fatigue strength at the maximum working speed are calculated;Further,based on the corrected S-N curve fatigue life evaluation model,the fatigue life prediction model under the coupling of multiple physical field for compressor blade is established.Finally,the modal analysis of highpressure compressor blade is completed to obtain its vibration modes and natural frequencies.（3）surrogate modeling of multi physical field performance response for high pressure compressor blade based on sequential sampling strategy.The establishment design optimization model with of high precision and high efficiency is important for design optimization of compressor blade,and how to select reasonable sampling points and establish surrogate model is an important link of model confirmation and accuracy verification.This thesis proposes a samples adding strategy for multi outputs surrogate modeling based on sample contribution.This method can comprehensively consider the global representativeness and overall volatility of the sample points to be selected,and effectively improve the efficiency of the surrogate model training.Secondly,combining this strategy with BP neural network algorithm,a surrogate modeling method for highpressure compressor blade with highly nonlinear and multi outputs response is proposed under multi physical field coupling.（4）Design optimization of high pressure compressor blade based on intelligent optimization algorithm.Firstly,taking the weight minimization as the objective function,the geometric parameters of blade plane cascade as the design variables,and considering the performance constraints such as fatigue constraints,boost ratio and efficiency,the optimal design model of compressor blade is established in this paper.Secondly,the design optimization problem is solved by combining the augmented multiplier method and the standard particle swarm optimization algorithm.Finally,the optimization results are compared with the performance of the initial compressor blade.