Aeroelastic instabilities simulations on turbofan HP compressorblisk at surge-like reversed flow conditions

Sammanfattning: This paper presents the work done at the High Pressure Compressor design division of Safran Snecma to simulate the flutter behaviour of a compressor blisk at reversed flow conditions. The report states the preliminary phase of modelling the reversed flow on an entire compressor with a stationary simulation and the single blade aeroelastic study results obtained. One can then get interpretations on the blow down aerodynamics that can affect the mechanical behaviour of the blade. Eight simulations of a single blade model have been done on two aeroelastic configurations, each one on a rotor from two different compressor designs. By investigating the airflow around the blade profiles, it becomes possible to get values on the aerodynamic damping on the blade. As presented below, even with strong surge stresses, the compressor stage will remain flutter-free.