Role of aerodome in pulsation/oscillation control and aeroheating reduction

Abstract

There exist two distinct modes of flow instability, namely pulsation and oscillation, related to the flat-ended cylinder with pointed spike in high-speed flights. A new method is proposed in this article to weaken the pressure fluctuations and aeroheating acting on the cylinder, through mounting an aerodome on the spike tip, which creates a cavity-like flow in front of the afterbody. Turbulent, axisymmetric flow at a freestream Mach number of Ma∞ = 6.0 and a Reynolds number (based on the cylinder diameter D) of ReD = 0.13 × 106 is simulated using a temporally and spatially second-order-accurate finite volume method. Numerical results are verified by comparison with the experimental data available in the open literature. It is shown that flow pulsation under the spike length of L/D = 1.0 can be totally controlled as the aerodome diameter increases to DA/D = 23.0%, whereas flow oscillation under the spike length of L/D = 2.0 is suppressed as the aerodome diameter reaches DA/D = 10.0%. Besides, the combination of the double-aerodome and sonic jet is proved the most effective way to provide thermal protection for the afterbody, which smooths down the heat flux peak in the vicinity of the reattachment.