Research on aeroelastic phenomena in airfoil cascades an experimental investigation of the unsteady aerodynamic of a classical air foil cascade in translation

The advent of high tip-speed, high work, blading in the fan stages of advanced gas turbine engines has led to the recognition of a new type of blading instability - unstalled supersonic flutter. As a result, a concerted effort to develop an appropriate predictive mathematical model has taken place. To determine the range of validity and to direct refinements to the basic flow model, fundamental supersonic oscillating cascade data are required. The experiment described herein is directed at significantly extending the range of existing supersonic cascade data to include translation mode oscillations. In particular, the fundamental time-variant translation mode aerodynamics are determined for the first time for a classical airfoil cascade in supersonic inlet flow field over a range of interblade phase angles at a realistic reduced frequency value. These unique experimental data are then correlated with predictions obtained from an appropriate state-of-the-art harmonically oscillating flat plate cascade aerodynamic analysis.