Conjugate heat transfer and thermal elastic coupling simulation of air cooledturbine by taking account of transition flows

Abstract:

The 3D NS equation solver was coupled with the heat conduction solver based on unstructured meshes and Gama-Theta transition model, the direct-coupled method and LUSGS implicit method were adopted, and the conjugate heat transfer (CHT) simulation platform was established. The temperature was transmitted between interfaces by the area-weighted interpolation method to ensure the flux conservation and accuracy. The CHT numerical results were compared with experimental data of the 5411 experimental condition of MARKII blade. The thermal-elastic coupling solver based on second unit was developed, and was compared with analytic solutions of the hollow cylinder. The boundary temperature calculated by CHT simulation was transmitted into the finite element solver to calculate the displacement and thermal stress. It is indicated from the result of CHT simulation that the eddy viscosity calculated in the most of pressure surface and the area before transition of the suction surface is better agreement with the real flow. Because the eddy viscosity has a great influence on heat transfer simulations by influencing the temperature diffusion coefficient, the accuracy of heat transfer calculations is higher, and the result of static pressure simulations of Gama-Theta and SST is in good agreement with experimental results. The thermal-elastic coupling simulation results show that the distribution trend of the thermal stress and displacement of MARKII blade is reasonable. The Gama-Theta model affects the accuracy of the thermal-elastic coupling simulation indirectly by affecting the CHT simulation, and makes the calculated thermal stress more reasonable.