Comparative studies of two POD methods for airfoil design optimization

Proper-orthogonal-decomposition (POD) methods have recently been developed for the design of airframe components. In this paper, two POD-based approaches have been studied: the gappy POD reconstruction procedure [1], and the gradient approach [2]. Both methods do not require a projection onto the computational fluid dynamics (CFD) governing equations but are, instead, a collection of flow snapshots that covers the parameter ranges of interest. Their performance on the inverse design of airfoil shapes have been compared and evaluated. Our studies show that while both methods are efficient and accurate, once appropriate flow snapshots have been collected, the gradient-based method is generally more accurate.