Numerical simulation on static aerodynamic characteristics of supersonic cavities

Abstract

A numerical study on supersonic cavity flow is carried out, where the influence law of the freestream parameters and configuration factors on static aerodynamic characteristics is investigated, focusing on the change of pressure distribution on the cavity walls at high and low Mach numbers. It is found that with the Mach number increment at high speeds (M>2), the pressure peak on the rear side of the cavity bottom floor rises, and the change in pressure distribution on the cavity walls shows a variating trend in flow type from a closed-cavity flow to an open-cavity flow, which is consistent with the law at low speeds (M≤2). At high speeds, the change in Reynolds number has a certain impact on the pressure distribution in the cavity, which is inconsistent with the law at low speeds. The increase of Reynolds number will increase the pressure on the rear side of the cavity bottom floor and on the rear wall, and the greater the Mach number, the greater the difference caused by Reynolds number variation. When the length-to-depth ratio increases at high speeds, the pressure peak on the rear side of the cavity bottom floor decreases, and the flow type is changing from an open-cavity flow to a transitional-cavity flow, which is consistent with the law at low Mach numbers, while the pressure variation is greater at high speeds. The influence of the length-to-width ratio on the pressure distribution is relatively small, and the increase of length-to-width ratio increases the pressure peak on the rear side of the cavity bottom floor slightly. Spanwise bending has a certain impact on the pressure distribution. The pressure peak on rear side of the bottom floor increases when the cavity is bending, which is consistent with the influence caused by length-to-width ratio increment.