Three Dimensional Unsteady Flow Around a Turbine Blade Oscillating in Bending Mode — An Experimental and Computational Study

Abstract

An experimental and computational investigation has been conducted on the aerodynamic response of a turbine blade oscillating in a three dimensional bending mode. Detailed blade surface unsteady pressure measurements have been obtained for a range of reduced frequency, from a test facility with clearly defined boundary conditions as described by Bell & He (1997). The measurements presented herein provide reliable 3D test cases which display significant three dimensional effects. These test cases have been utilised towards the validation of a 3D time-marching Euler method, and the ability of this numerical scheme to capture the relevant unsteady aerodynamics is examined. Comparisons between the predicted and measured unsteady pressure response show a satisfactory agreement over the full range of reduced frequency. Furthermore, the linearity of the test configuration is also investigated, and both experimental and numerical results demonstrate a quite linear behaviour of the unsteady aerodynamics.