LINEARIZED UNSTEADY AERODYNAMICS FOR TURBOMACHINERY AEROELASTIC APPLICATIONS

The unsteady aerodynamic analyses developed for turbomachinery aeroelastic predictions must be applicable to the moderate through high frequency unsteady flows that are excited by structural motions and aerodynamic interactions between adjacent blade rows and occur over a wide range of operating conditions. In addition, because of the large number of controlling parameters involved, there is a stringent requirement on computational efficiency. The traditional practice has been to invoke a number of simplifying assumptions, e.g., small-amplitude unsteady excitations, high Reynolds number flow, etc., in the development of analyses intended for use in design applications. In particular, during the past decade researchers have developed general inviscid unsteady aerodynamic linearizations that account for the effects of the nonuniform steady-flow phenomena associated with real blade geometry and mean blade loading on the unsteady aerodynamic response of two-dimensional cascades. In this paper several recent advances to this theory are reviewed. Example results are also presented to illustrate the current status of the theoretical model and the associated numerical prediction capabilities.