Boundary-Layer Stability Analysis of HIFiRE-5b Flight Geometry

Abstract

Boundary-layer stability and laminar-to-turbulent transition are examined on the HIFiRE-5b flight geometry using provided flight conditions at two flight times. The parabolized stability equations and spatial biglobal theory are used for this analysis because they are efficient and accurate techniques to model the transition process. Two-dimensional and three-dimensional instabilities are investigated with the parabolized stability equations. The primary instabilities investigated here are the second mode along the attachment line and stationary crossflow away from the geometric planes of symmetry. The spatial biglobal equations are used to calculate secondary instabilities within a stationary crossflow vortex. This work demonstrates that coupling nonlinear parabolized stability equations with spatial biglobal equations could provide a generalized technique to predict transition onset in flows with stationary crossflow as the dominant mechanism. The transition onset location is predicted by the location of the secondary instability neutral point. Moreover, the observed amplification of the secondary instabilities could potentially be the predictor for breakdown to turbulence, and it shows good agreement with the flight data.