Comparison of Fluid-Structure Coupling Methods for Blade Forced Response Prediction

A time-marching coupled method has been applied to a high pressure compressor forced response case. The purpose of the study is to compare the contribution of the coupled scheme against the state of the art decoupled methodology. Although the time-marching scheme allows for a stronger coupling between the motion and aerodynamic field, results have shown good agreement with the decoupled method. The additional computing cost arising from the long transient state and the small difference in amplitude prediction with the decoupled scheme reduce the interest for the coupled one. A new transient state method is proposed to combine both coupled and decoupled schemes features. Here, the forcing and damping functions are extracted during the mechanical transient state of the coupled simulation and forced response is calculated as in the decoupled method. Results have shown good agreements with the experiment and all the methods are compared in terms of underlying assumptions and performances.