Experimental and Numerical Performance Analysis of a Self Starting, Three-Dimensional SCRamjet Intake

Abstract

In the present paper, a three-dimensional intake model is investigated in a blow-down wind tunnel and results are compared and complemented with numerical simulations (Reynolds-averaged Navier-Stokes simulations). The intake model was equipped with a movable cowl and therefore the internal contraction ratio was variable and was adjusted to the self starting condition. Three different conditions were investigated: i) at a free stream Mach number of 7, a v-shaped cowl geometry was investigated, ii) at a free stream Mach number of 7 a straight cowl geometry was investigated, and iii) the v-shaped cowl geometry was investigated at a free stream Mach number of 6. Furthermore a one-dimensional post analysis was performed, to calculate overall engine parameter from stream thrust averaged intake performance parameter. The numerical simulations were validated on the basis of wall pressure and rake pressure measurements and the match was generally well. Performance wise, the v-shaped cowl was slightly superior compared to the straight cowl. For the Mach 7 configurations maximum back pressure ratios of approximately 120 were measured, which is about 4 times the nominal operating pressure ratio. For the Mach 6 case, the maximum static back pressure ratio dropped to about 80, which again is approximately 4 times the nominal operating pressure ratio.