Effect of non-axisymmetric tip clearance on the aerodynamic performance of a 1.5 stage axial flow turbine
The deviation of the rotor shaft rotation axis from the cylinder geometric axis leads to a non-axisymmetric tip clearance,which has strong effect on the aerodynamic performance and structure stability of turbomachinery.This paper contributes to the investigation of this effect on a 1.5 stage axial flow turbine using numerical simulations.A commercial Computational Fluid Dynamic(CFD)software is employed to solve the Reynolds averaged Navier-Stokes(RANS)equations.Three different blade tip clearances were investigated,by setting different rotor eccentricities.For each clearance height,three flow fields were simulated under three different operating conditions.The simulation results are verified on different set of grids and validated by being compared with the experimental date.The simulation results suggest that the self-excited force increases with the eccentricity of the rotor.For the case in this paper,when the tip clearance height ratio is lower than 1.3%,the turbine isentropic efficiency decreases with the increase of the rotor eccentricity,whereas,the variation of the efficiency is opposite when the tip clearance height ratio is higher than 1.3%.
Axial Flow Turbine Tip Clearance Eccentricity Structural Stability Numerical Simulation
Xiaodong Wang Qijia Deng Shun Kang
North China Electric Power University,Beijing,China North China Electric Power University,Beijing,China;Xian Modern Control Technology Research Institu
国际会议
桂林
英文
1-11
2013-07-16（万方平台首次上网日期，不代表论文的发表时间）