Research On The Prediction Method Of Compressor Tip Clearance And Characteristic Based On Gas-Thermal-Solid Coupling

In the multi-dimensional design system of axial compressor,the low-dimensional characteristic prediction method in the initial stage plays an important role.In order to improve the comprehensiveness and accuracy of the compressor characteristic prediction method and accelerate the aerodynamic design process,this paper firstly establishes a blade tip clearance prediction model applicable to dry air,secondly combines the blade tip clearance prediction model with the characteristic prediction model and investigates a compressor characteristic prediction method based on gas-thermal-solid coupling,finally,in order to satisfy the applicability of the blade tip clearance prediction model to the operating conditions of multiple working fluid,the blade tip clearance prediction method for dry air is modified under water ingestion conditions.The details of this paper are as follows:Firstly,accounting for aerodynamic,thermal,and centrifugal load impacts on each compressor component,a method is devised to determine the deformation of the casing,blade,and disk under their combined effects,achieving rotor blade tip clearance prediction.The predicted and tested values of blade tip clearance between a compressor and a fan at each speed were compared.The maximum relative error was 11.70% at 98.03% of the test speed for the first rotor stage of a fan,verifying the accuracy of the rotor tip clearance estimation method.The minimum thickness of a fan casing and a 50% thickened fan casing are chosen for tip clearance prediction,scrutinizing the discrepancies in rotor tip clearance prediction outcomes stemming from the casing’s intricate structure and uneven thickness distribution.Secondly,utilizing the stage-stacking method,the axial compressor’s distinctive prognostication method,incorporating fixed vane tip clearance,is devised by merging the loss model with the deviation angle model.This methodology is integrated with characteristic prediction techniques to yield a one-dimensional performance forecasting method for axial compressors based on the synthesis of gas-thermal-solid multiphysics fields.Results reveal that,compared to the fixed blade tip clearance characteristic prediction,the coupled gas-thermal-solid multiphysics field approach enhances performance parameter prediction accuracy.The total pressure ratio at 100% speed experiences a 1.057% improvement in prediction accuracy,while adiabatic efficiency prediction accuracy improves by 0.671%.Thirdly,finite element computations of gas-thermal-solid multifield coupling for a specific fan under water ingestion conditions are employed to quantify thermal and shock load characteristic indices on components,and to correct the rotor blade tip clearance estimation method under water ingestion conditions.Comparing the predicted blade tip clearance of the first stage rotor blade of a fan under water ingestion conditions with the 3D simulation results,the maximum relative error appears at 1% water ingestion condition at100% speed,5.484%,and the minimum relative error appears at 4% water ingestion condition at 50% speed,0.491%,which verifies the accuracy of the correction method.Furthermore,based on radial deformation outcomes of the casing,blade,and disk under separate water ingestion and various loads,the deformation of each component and the alteration of blade tip clearance in thermal states due to water ingestion are summarized.