# Numerical Investigation of a Rotating Double Compression Ramp Intake

## TL;DR

This study numerically investigates the transient shock reflection over a rotating double wedge in high-speed flow, revealing how wedge rotation and length affect pressure and shock wave behavior, with implications for supersonic and hypersonic intakes.

## Contribution

It introduces a numerical analysis of the transient shock reflection phenomenon during the rotation of a double wedge, exploring effects of wedge length and rotation angle on shock and pressure.

## Key findings

- Wedge rotation significantly increases pressure due to shock reflection.
- Wave angles are larger at lower chord ratios, affecting pressure distribution.
- Changing wedge length influences shock system behavior and pressure gains.

## Abstract

The intakes of air-breathing high-speed flying vehicles produce a large share of the thrust propulsion. Furthermore, the propulsion performance of these engines increases when the single-ramp intake is replaced with a multiple-ramps intake. Many scholars numerically and experimentally studied the high-speed engine performance over static single and multiple compression ramps. However, the transient behavior of the flow during the rotation of the double compression ramp from a single ramp is not fully investigated. The present paper aims to numerically investigate the transient shock reflection phenomenon over a rotating double wedge. The problem will start with a 3-Mach number inviscid flow over a single wedge. Then, a portion of the wedge will be rotated upstream at a quite low trailing Mach number to avoid the significant lag effect in the shock waves system. This idea could be applied in the supersonic intake or extensionally in the hypersonic intake of scramjets with a somehow complex mechanism. Further, the length of the rotating portion of the wedge will be changed three times to study its effect on the shock system. The results show a high gain in the pressure due to the rotation of the wedge. Moreover, the wave angles were larger at the low chord ratio value of $w_2/w_i= 0.25$ than at the high values of $w_2/w_i$ at the same second wedge rotating angle, $\theta_2$, resulting in a higher pressure distribution.