Multidisciplinary Coupling Analysis For The Cooling Effects Of Gas Turbine Air-Cooling Vanes

The inlet total temperature of turbines is increasing by the purpose of getting higher thrust-weight ratio.So complex cooling structures have been designed to protect turbine blades and vanes from high temperature.The usage of cooling structures decreases the temperature level and increases the temperature gradient of vanes at the same time.Stress will be generated inside the vanes which will decrease the strength.The premise of optimizing cooling structures and strength verification is precise prediction of temperature fields and stress fields.Single aerodynamic calculation,heat transfer calculation or strength calculation can't meet the complex requirement.This paper calculated and analyzed the steady temperature fields and stress fields of C3 X vane by the theory of multidisciplinary which includes fluid dynamic,heat transfer and mechanics of materials with the help of multi-physical fields calculation platform.The main jobs of this paper are listed as follows:1.Three uncertain factors in the gas-thermal coupling calculation were confirmed which include the height of first layer of the mesh at the vane surface of the fluid field y(1),the mesh numbers of three simulation fields and turbulence models.Firstly,y(1)=0.001 mm was chosen from 0.01 mm,0.005 mm and 0.001 mm by contrasting.Secondly,the verification of mesh independence and the selection of turbulence models were finished by the usage of orthogonal experiment method.2.Three uncertain factors in the thermal-solid coupling calculation were confirmed which include the numbers of meshes,loads and reference temperature.Firstly,0.38 million was taken as the mesh number by the verification of mesh independence.Secondly,thermal stress was much bigger than aerodynamic stress so that the aerodynamic loads can be ignored.Thirdly,the reference temperature was set as 400 K in order to decrease the error of stress calculation.3.The temperature fields of the vane under different operation conditions were simulated and analyzed.Conclusions were drew by contrasting the temperature fields of the filled vane and cooled vane under experiment operation condition: by the influence of cooling air,the highest temperature of the vane decreased by 14.9% and the temperature unevenness increased obviously.The biggest unevenness in the radial direction was 546% which was located at 10% radial section and the smallest one was 440% which was located at 70% radial section.The biggest unevenness in the axial direction was 2759% which was located at 10% axial section and the smallest one was 503% which was located at 50% radial section.The change of temperature fields of cooled vane with the turbulent intensity and uneven distributed total temperature at the inlet of main stream was also analyzed respectively.4.The stress fields of the vane under different operation conditions were simulated and analyzed.Conclusions were drew by contrasting the stress fields of the filled vane and cooled vane under experiment operation condition:by the influence of cooling air,the average Von Mises stress,average equivalent strain and max deformation at the 50% radial section were decreased by 56.6%,57.4% and 48.9% respectively;and the yield limit was increased by 42.65%.The change of stress fields of cooled vane with the turbulent intensity and uneven distributed total temperature at the inlet of main stream was also analyzed respectively.