Comparison of planar fluorescence measurements and computational modeling of shock-layer flow

Abstract

Planar laser-induced fluorescence is used to image transient and quasisteady flow phenomena associated with an impulsively started supersonic jet incident on a circular cylinder. The transient phenomena observed are consistent with established theoretical work on the development of nozzle flows in a shock tunnel and with well-understood shock reflection processes. The technique is also used to measure the rotational temperature in the jet and in the shock layer on the cylinder after the establishment of quasisteady flow conditions. The inviscid flow between the bow shock and the edge of the boundary layer and the viscous flow within the boundary layer are modeled numerically using an iterative scheme. Good agreement is achieved between the computational and experimental results for most of the imaged field, except for the region near the shock vertex, where flow nonuniformities near the centerline perturb the shock from the shape expected for a uniform incident flow.