Thermomechanical analysis of a turbo charger turbine wheel based on CHT-calculations and measurements

摘要

CFD, FEA and experimental testing have been combined in order to find lifetime limiting design deficiencies of a turbo charger turbine wheel.rnBased on two steady state CHT-calculations the heating process of the wheel has been simulated in a transient calculation. The resulting temperature distribution serves as boundary condition for a structural analysis.rnTaking into account centrifugal forces, the influence of the thermal stress is evaluated. Moreover, a method has been developed to extrapolate the transient temperature results according to a modified turbine mass flow and rotational speed. Results from experiments are used for the extrapolation method as well as for the numerical boundary conditions.rnA modified design of the back contour has been calculated and compared to the original design.