Fatigue analysis of a cylindrical turbine disk with integrated heat pipes

Using thermomechanical finite element simulations, the structural effects of a heat pipe inside a cylindrical turbine disk are investigated in terms of fatigue strength considerations. The simulation includes transient thermal boundary conditions and rotational speeds according to a simplified flight mission of an aero engine. The heat pipe is modeled as a solid cylinder with a high temperature dependent thermal conductivity. In previous studies the structural effects of a heat pipe inserted inside a turbine disk have been discussed in terms of temperature and stress influences. In this paper, the damage parameter by the Smith Watson and Topper method P_SWT is used for life prediction until technical cracking can be expected. Several high loaded areas in the disk have been identified and evaluated. Furthermore, a parameter study regarding different heat inputs at the outer radius of the disk is presented. The results show that the heat pipe does not reduce the durability of the disk. The stress peaks in the heat pipe cavity are not critical. Furthermore, due to the cooling effect of the heat pipe the rim area of the cylindrical disk can get significantly higher loaded.