An Efficient Algorithm for Solving the Generalized Airfoil Equation

Abstract

In this paper, we develop an efficient Petrov-Galerkin method for the generalized airfoil equation. In general, the Petrov-Galerkin method for this equation leads to a linear system with a dense coefficient matrix. When the order of the coefficient matrix is large, the complexity for solving the corresponding linear system is huge. For this purpose, we propose a matrix truncation strategy to compress the dense coefficient matrix into a sparse matrix. Subsequently, we use a numerical integration method to generate the fully discrete truncated linear system. At last we solve the corresponding linear system by the multilevel augmentation method. An optimal order of the approximate solution is preserved. The computational complexity for generating the fully discrete truncated linear system and solving it is estimated to be linear up to a logarithm. The spectral condition number of the truncated matrix is proved to be bounded. Numerical examples complete the paper.