Volume 111 (2002)


In Memoriam - Professor Bilicki

No. 111, 2002, 37-50

3D inviscid flutter of IV Standard Configuration. Part I. Harmonic oscillations


A three-dimensional nonlinear time-marching methocl and numerical analysis for aeroelastic behaviour of oscillating blade row of the IV Standard Configuration has been presented. The approach is based on the solution of the coupled fluid-structure problem in which the aerodynamic and structural equations are integrated simultaneously in time. In this formulation of a couplecl problem, the interblade phase angle at which stability (or instability) would occur, is a part of the solution. The ideal gas flow through multiple interblade passage (with periodicity on the whole annulus) is described by the unsteady Euler equations in the form of conservative laws, which are integrated by use of the explicit monotonous second order accurate Godunov-Kolgan
finite volume scheme and a moving hybrid H-H (or H-O) grid. The structure analysis uses the modal approach and 3D finite elenent model of the blacle. The blade motion is assumed to be a linear combination of modes shapes with the modal coefficients depending on time. The influence of the natural frequencies on the aeroclynamic for the Fourth Standard Configuration is shown. The instability regions for the first two modes shapes and the distribution of the aerodamping coefficient along blade length were shorwn for a harmonic oscillation with the assumed interblade phase angle.


Flutter, Blades, Inviscid flow