COUPLED THERMAL-MULTIPHASE FLOW ANALYSIS IN QUENCHING PROCESSES FOR RESIDUAL STRESS OPTIMIZATION IN COMPRESSOR AND TURBINE DISKS

摘要

The durability of compressor and turbine disks in jet engines is strongly influenced by residual stresses caused by the manufacturing process. The main goal of our work is the simulation and optimization of the heat treatment, to adjust reliably the residual stresses. After forging and drilling the disk blank is heated in a furnace. In the following quenching process the disk is cooled down in an oil bath, whereas plastic deformations occur in the disk. The coupled thermal-flow analysis is accomplished using a commercial CFD code. During the quenching process radiation, boiling and condensation of the oil as well as appropriate heat transfer mechanisms are considered. The heat transfer due to film, transition and nucleate boiling is modeled via user-defined functions. Subsequently, nonlinear residual stress calculations are performed in a commercial FEM program based on the determined temperature field.