PSEを用いた超音速自然層流翼の飛行試験条件における遷移解析

Abstract

Linear stability analysis of compressible three-dimensional boundary layers on a supersonic natural laminar flow wing, which has strong crossflow and wall curvature effect extremely near the leading edge, is conducted at the flight test condition by solving parabolized stability equations (PSE) as well as the eigenvalue problem in linear stability theory (LST). The effects of the non-parallelism and the wall curvature which the LST approach excludes, and the normalization condition of the PSE method on the stability are investigated, focusing on both stationary and traveling modes subject to crossflow instability and the first unstable mode. Subsequently, the so-called e to the nth power method is used as a transition prediction method coupled with the fixed β technique. Finally each N factor map on the wing based on the PSE approach is compared with the result by LST. It is found that stationary modes are very sensitive to the wall curvature compared with traveling modes, and that some shortcomings related to the pathological problem, which existed on the results by the LST approach, can be solved by the current PSE method.