Methods for calculating the response of structures to inhomogeneous turbulent flows

Abstract

Problems involving the response of structures to turbulent flows are usually modeled using a linear approach. The incoming turbulence is described using a Von Karman or Liepmann spectrum using typical turbulence velocity and length scales. However, these models only apply to homogeneous turbulence and so inhomogeneous flows can only be treated in an approximate manner. This paper will describe an alternative approach in which the turbulent flow is decomposed into a set of uncorrelated modes using proper orthogonal decomposition. The response of the structure to each mode can then be considered independently and the results summed incoherently to give the complete response. However, to obtain the proper orthogonal modes the flow must be measured in great detail. It will be shown that this requirement can be reduced if measurements are limited to the most energetic parts of the flow.