Abstract
In numerical methods of unsteady subsonic lifting surface theories, several chordwise quadratures are required each of which contains a unique singularity of kernel function. Suitable treatment of these quadratures often improves considerably convergence of the whole solutions. In this paper two kinds of kernel function[1+x0/√x0x02+YY2] (Part I) and ln |x0| (Part II) are investigated through as many methods as possible, and as systematic as possible. The results of Part I show that the ALWAY's method is extremely superior to all of other methods for most of the cases investigated and that individually restricted applicability of each remaining method is clarified. The results of Part II show that the method developed by us is drastically excellent.
