Experimental and Computational Analysis of Model–Support Interference in Low-Speed Wind-Tunnel Testing of Fuselage-Boundary-Layer Ingestion

Abstract

Junction flow caused by the aerodynamic interaction between a wind-tunnel model and the support structure can largely influence the flowfield and hence the experimental results. This paper discusses a combined numerical and experimental study which was carried out to mitigate the model–support interference in a wind-tunnel test setup for the study of fuselage boundary-layer ingestion. The setup featured an axisymmetric fuselage mounted through a support beam, covered by a wing-shaped fairing. The junction flow appearing at the fuselage–fairing connection produced undesired flow distortions at the fuselage aft section, due to the formation of an horseshoe vortex structure at the fairing leading edge. Numerical and experimental analysis were performed with the aim of reducing the distortion intensity by improving the fairing design. Results show that modifying the leading-edge shape of the fairing effectively decreased the flowfield distortions. Moreover, the addition of a dummy fairing diametrically opposed to the first one was found to be beneficial due to the enhancement of the configuration symmetry.