Computational and experimental investigation into aerodynamic interference between slender bodies in supersonic flow

Abstract

Aerodynamic interference can occur between high-speed bodies when in close proximity. A complex flowfield develops where shock and expansion waves from a generator body impinge upon the adjacent receiver body and modify its aerodynamic characteristics. The aims of this paper are to validate a computational prediction method, to use the predicted solutions to interpret the measured results and to provide a deeper understanding of the associated flow physics. The interference aerodynamics for two slender bodies were investigated through a parametric wind tunnel study where the effect of axial stagger was investigated for different receiver body incidence angles. Measurements included forces and moments, surface pressures and shadowgraph visualisations. Supporting computational predictions provided a deeper understanding of the underlying aerodynamics and flow mechanisms. Good agreement was found between the measured and predicted interference loads and surface pressures for all configurations. The interference loads are strongly dependent upon the axial impingement location of the primary shockwave. These induced interference loads change polarity as the impingement location moves aft over the receiver. Distinct interference characteristics are observed when the receiver is placed at high positive incidence, where the impinging shock has a strong effect on the crossflow separation location. Overall, the observed interference effects are expected to modify the subsequent body trajectories and may increase the likelihood of a collision.