Micro-Ramps for Hypersonic Flow Control

Mohd R Saad,Hossein Zare-Behtash,Azam Che-Idris,Konstantinos Kontis

doi:10.3390/mi3020364

Mohd R Saad, Hossein Zare-Behtash + Show 2 more

Open Access

https://doi.org/10.3390/mi3020364

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Abstract

Shock/boundary layer interaction (SBLI) is an undesirable phenomenon, occurring in high-speed propulsion systems. The conventional method to manipulate and control SBLI is using a bleed system that involves the removal of a certain amount of mass of the inlet flow to control boundary layer separation. However, the system requires a larger nacelle to compensate the mass loss, larger nacelles contribute to additional weight and drag and reduce the overall performance. This study investigates a novel type of flow control device called micro-ramps, a part of the micro vortex generators (VGs) family that intends to replace the bleed technique. Micro-ramps produce pairs of counter-rotating streamwise vortices, which help to suppress SBLI and reduce the chances of flow separation. Experiments were done at Mach 5 with two micro-ramp models of different sizes. Schlieren photography, surface flow visualization and infrared thermography were used in this investigation. The results revealed the detailed flow characteristics of the micro-ramp, such as the primary and secondary vortices. This helps us to understand the overall flow physics of micro-ramps in hypersonic flow and their application for SBLI control.

Highlights

Hypersonic aero-vehicles rely on optimum performance from their air-breathing propulsion system.the prominent problem faced by the propulsion system is the phenomenon known as shock wave-boundary layer interactions (SBLIs) which cause boundary layer separation and adverse pressure gradients, that eventually lead to total pressure loss and flow distortion in the intake section [1,2]
The prominent problem faced by the propulsion system is the phenomenon known as shock wave-boundary layer interactions (SBLIs) which cause boundary layer separation and adverse pressure gradients, that eventually lead to total pressure loss and flow distortion in the intake section [1,2]
The current study extends the scope of collective research efforts done on micro-ramps by subjecting it to a Mach 5 flow

Summary

Introduction

The prominent problem faced by the propulsion system is the phenomenon known as shock wave-boundary layer interactions (SBLIs) which cause boundary layer separation and adverse pressure gradients, that eventually lead to total pressure loss and flow distortion in the intake section [1,2]. All of these reduce the overall propulsive efficiency of a hypersonic vehicle. The micro-ramp is a recently developed novel flow control device [3,4,5,6] It is a part of the micro-vortex generator family that has shown potential in solving the adverse phenomena. Apart from this, the advantages that can be listed are cost-effectiveness, physically robustness and independence of power source

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