Stochastic Store Trajectory of Ice Models from a Cavity into Supersonic Flow

Abstract

Store separation of prolate spheroid ice models with fins from a length-to-depth cavity into freestream was conducted experimentally to statistically investigate the existence of a bifurcation in trajectory during passage through the shear layer. A force-ejection mechanism provided consistent initial velocity larger than gravity drop at several different initial pitch angles. Trajectories were observed in pitch and yaw planes with two high-speed cameras. Results reveal a mean neutral trajectory from a initial pitch angle with mean reversal for smaller and mean divergent for larger initial angle. The standard deviation of center of gravity (c.g.) displacement and pitch angle increased for all cases after passage through the shear layer with a slight bifurcation for the case. In addition, the distribution of c.g. displacement of cases showed bimodal and modal switching when the store passed through the shear layer. The statistical results revealed a bifurcation and the distribution of trajectories cannot be described as symmetric Gaussian distribution for evaluating the store trajectory.