Models of steam force and torque of a rotor subjected to the leakage of tip clearance

Abstract

The topic of this paper is focused on the models of steam force and torque of a rotor subjected to the leakage of tip clearance. The unsteady three-dimensional Navier-Stokes solver is used to simulate the flow field for a rotating blade row with a tip clearance. The basic algorithm time marches the fully three-dimensional unsteady equations of motion expressed in a finite volume form. The Baldwin-Lomax model is used as turbulence model. By simulating the complex flow field including oscillating tip clearance with rotor vibration, the instantaneous asymmetry and oscillatory pressures acting on the surfaces of the blade row can be acquired, and the instantaneous steam force and torque acting on the rotor can be calculated. A new nonlinear model of steam force is created in this paper, and a model of steam torque excited by leakage is also reported.