3D INVISCID FLUTTER OF ROTOR BLADES AND STATOR/ROTOR STAGE

Abstract

Numerical calculations of the 3D transonic flow of an ideal gas through turbomachinery rotor blade row and stator, rotor blades moving relatively one to another with taking into account the blades oscillations are presented.

The approach is based on the solution of the coupled aerodynamic-structure problem for the 3D flow through the turbine stage in which fluid and dynamic equations are integrated simultaneously in time.

An ideal gas flow through the mutually moving stator and rotor blades with 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 structure analysis uses the modal approach and 3D finite element model of a blade. There has been performed the calculation for the last stage of the steam turbine with rotor blades of 0.765m.