Evaluation of side spillage for a hypersonic air intake using computational fluid dynamic techniques

Abstract

Mass capture ratio of a hypersonic air intake is one of the most important performance parameters. However, no a priori estimate of its value exists for use in initial design exercise of a hypersonic vehicle. In the present work, an air intake of a non-axisymmetric scramjet engine, designed using stream thrust methodology, is studied using computational fluid dynamic techniques. A large amount of air mass flow rate is observed to spill from the sides, which is not accounted for in the initial design phase. In absence of even an approximate estimate of this spillage, computational fluid dynamic studies become the only available tool to evaluate the mass capture ratio. Simulations are also carried out with a side wall at the intake to stop spillage. Although mass capture ratio and static pressure at combustor entry improve, deterioration in other flow parameters such as static temperature, Mach number and total pressure is observed.