ESTIMATION OF NON-LINEAR DAMPING PARAMETERS IN A NORMAL TRIANGULAR ARRAY SUBJECT TO FLUIDELASTIC INSTABILITY

摘要

The non-linear damping parameters associated with a coupled fluidelastic system have been extracted using the non-linear decrement method. The response of a single flexible tube in a five row normal triangular tube array (P/d =1.32) was recorded over a range of freestream velocities with air as the working fluid. The structural damping has been set so as to avoid fluidelastic instability. The linear and cubic fluidelastic damping parameters have been obtained. Using these identified quantities, the limit cycle amplitudes for the system at lower structural damping levels have estimated. Good agreement between the predicted values and the experimental data is achieved.