Abstract
Nonlinear stability of three-dimensional supersonic boundary layers on JAXA's experimental airplane called NEXST-1 is investigated for the case in which first-mode instability is dominant. Several nonlinear mode interactions are numerically examined by solving nonlinear parabolized stability equations. The existence of the standard initial amplitude is assumed, and its value is estimated from the flight data of the NEXST-1. It is shown that disturbances with a critical parameter (ω0, β0) predicted by linear parallel stability theory are linearly amplified until transition sets in. Then the initial amplitude correlates with the measured transition location is found to be approximately 10-6 regardless of nonlinear interactions presented.
