Abstract

This paper presents an integrated non-linear numerical model for aeroelasticity predictions of the long steam turbine blade, The approach is based on the solution of the coupled fluid - structure problem in which the aerodynamic and structural dynamic equations are integrated simultaneously in time, thus providing the correct formulation of a problem. The ideal gas flow around multiple interblade pa§§ages (with periodicity on the whole annulus) is described by the unsteady 3D Euler equations in conservative form, which are integrated by using the explicit monotonous second - order accurate Godunov-Kolgan, finite volume scheme and moving grids. In the structural analysis the modal approach is used. The natural frequencies and modal shapes of the blade were calculated using 3D finite element model. The instability regions for 5 modes shapes and the distribution ofthe aerodamping coefficient along the blade length were shown for a harmonic oscillation with the assumed interblade phase angle,