No. 114, 2003, 123-132
Abstract
A three-dimensional analysis for aerodynamic unsteady forces of the last stage steam turbine 13K215 rotor blades and total unsteady forces acting on the shaft from considered stage, have been presented. The numerical calculations were performed for different pressure distribution (p2=6000, 7500, 9000, 7500 Pa). The analysis of 3D transonic flow of an ideal gas through turbomachinery blade rows moving relatively one to another without taking into account the blades oscillations is presented. An ideal gas flow through the mutually moving stator and rotor blades in periodicity on the whole annulus is described by the unsteady Euler conservation equations, which are integrated using the explicit monotonous finite-volume difference scheme of Godunov-Kolgan and moving hybrid H-H grid. The algorithm proposed allows to calculate turbine stages with an arbitrary tangential and radial directions were found. Due to non-uniform pressure distribution the low frequency excitation appeared.
Keywords:
unsteady forces, steam turbine, blades, shaft