Identification of Fluid Dynamic Coefficients for Multiple Mode Vibrations of a Lightly Damped Rectangular Prism in Cross Flow

An experimental investigation of lightly damped multiple-mode vibrations of a rectangular prism in cross flow will be described. The identification of the fluid dynamic force coefficients is performed by means of a regression analysis (Least-Squares-Procedure) accompanied by online numerical simulation, which allows minimization of errors. Non-linear modelization of the equation of motion is shown, which is needed for stability discussion and to describe the response beyond the stability limit. The fluid dynamic damping will be chosen as the responsible control parameter in the model test for a supercritical Hopf bifurcation.