Behaviour of hypersonic wind tunnels diffusers at low Reynolds numbers

摘要

This paper deals with the behaviour of hypersonic wind tunnels diffusers at low Reynolds numbers. The phenomena that occur in the diffusers at relatively low Reynolds numbers are particularly critical Due to the interactions between shock waves and the large boundary layers present in the long throat, Which can reduce the maximum recovery pressure and therefore the efficiency of the diffuser. The aim Of the present paper is to correlate the results obtained by numerical simulations of the diffusers with The experimental results, obtained using a high enthalpy blow down arc jet facility. The numerical and Experimental results are in agreement and show that, for the range of Reynolds number investigated, the Diffuser efficiency is smaller compared to the values determined for similar diffusers operating at larger Reynolds numbers.