Abstract: This paper presents the turbulent separation features induced by blunt fins with a semicylindrical leading edge in the hypersonic flow. The nominal test conditions were freestream Mach number of 7.8 and unit Reynolds number of 3.5×10 7m -1. The results show that turbulent separation induced by blunt fins is unsteady and separation shock undergoes large scale low frequency motion. There are maximum values of standard deviations of wall pressure and heat transfer fluctuations normalized by the local mean level near the primary separation line. The maximum values are found to increase with the freestream Mach number. The leading edge diameter is a dominant parameter controlling the separation field scale and distribution shape of mean wall pressure and heat transfer in the leading edge region.

Key words: hyper sonic flow, sepa rated flow, interactional aerodynamics, blunt leading edges, pressure measurement, heat flux