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Flow in an idealized air-inlet with plane walls and a rectangular cross-section is experimentally investigated. The air-inlet is mounted on a plate, at a distance well removed from its leading edge. The experiments were conducted in a Ludwig tube at M ∞ = 5 and Re ∞L = 23 × 10 6 and 13 × 10 6 . A panoramic (optical) technique of measuring the heat transfer coefficient is for the first time applied to study the internal flow in an air-inlet. The data on the effect of the bluntness of the leading edges of the plate and the air-inlet cowl on the heat transfer coefficient distribution and the flow structure within the air-inlet are obtained. It is shown that in an air-inlet with large channel constriction an even small bluntness of the plate or the cowl can lead to global changes in the flow structure.

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Flow and heat transfer inside a generic inlet are investigated experimentally. The cross section of the inlet is rectangular. The inlet is installed on a §at plat at a signi¦cant distance from the leading edge. The experiments are performed in TsAGI wind tunnel UT-1M working in the Ludwieg tube mode at Mach number M ∞ = 5 and Reynolds numbers (based on the plate length L = 320 mm) Re ∞L = 23 · 10 6 and 13 · 10 6 . Steady §ow duration is 40 ms. Optical panoramic methods are used for investigation of §ow outside and inside the inlet as well. For this purpose, the cowl and one of two compressing wedges are made of a transparent material. Heat §ux distribution is measured by thin luminescent Temperature Sensitive Paint (TSP). Surface §ow and shear stress visualization is performed by viscous oil containing luminophor particles. The investigation shows that at high contraction ratio of the inlet, an increase of plate or cowl bluntness to some critical value leads to sudden change of the §ow structure.

An experimental and numerical investigation of a gas §ow on a §at plate near a single ¦n and a ¦n pair, generating crossings shocks, is performed. The study is focused on the plate bluntness in §uence on the §ow ¦eld and the heat transfer in the interaction region. The experiments are carried out in a short duration wind tunnel at Mach numbers M = 5, 6, and 8 and Reynolds numbers Re ∞L up to 27 · 10 6 . Luminescent substances are used for heat §ux and pressure distribution measurements and for the surface §ow visualization. In addition, the heat §ux is measured with thermocouple sensors. For a numerical §ow simulation, the three-dimensional (3D) Reynolds-averaged Navier Stokes (RANS) equations are solved using the q ω turbulence model. It is found that even a small plate blunting a¨ects heat transfer and pressure distributions signi¦cantly. Moreover, in the case of crossing shocks, it can cause a global transformation of the §ow structure in the area of the interaction between the shock waves and the boundary layer.