Investigation on Supersonic Flow Control Using Nanosecond Dielectric Barrier Discharge Plasma Actuators

A Nazarian Shahrbabaki,M Bazazzadeh,R Khoshkhoo,Jose Carlos Páscoa

doi:10.1155/2021/2047162

Abstract

In this paper, the effects of streamwise Nanosecond Dielectric Barrier Discharge (NS-DBD) actuators on Shock Wave/Boundary Layer Interaction (SWBLI) are investigated in a Mach 2.5 supersonic flow. In this regard, the numerical investigation of NS-DBD plasma actuator effects on unsteady supersonic flow passing a 14° shock wave generator is performed using simulation of Navier-Stokes equations for 3D-flow, unsteady, compressible, and k ‐ ω SST turbulent model. In order to evaluate plasma discharge capabilities, the effects of plasma discharge length on the flow behavior are studied by investigating the flow friction factor, the region of separation bubble formation, velocity, and temperature distribution fields in the SWBLI region. The numerical results showed that plasma discharge increased the temperature of the discharge region and boundary layer temperature in the vicinity of flow separation and consequently reduced the Mach number in the plasma discharge region. Plasma excitation to the separation bubbles shifted the separation region to the upstream around 6 mm, increased SWBLI height, and increased the angle of the separation shock wave. Besides, the investigations on the variations of pressure recovery coefficient illustrated that plasma discharge to the separation bubbles had no impressive effect and decreased pressure recovery coefficient. The numerical results showed that although the NS-DBD plasma actuator was not effective in reducing the separation area in SWBLI, they were capable of shifting the separation shock position upstream. This feature can be used to modify the structure of the shock wave in supersonic intakes in off-design conditions.

Highlights

Shock Wave/Boundary Layer Interaction (SWBLI) is a key phenomenon of fluid dynamics, and its analysis is important in many supersonic and hypersonic applications, especially in various supersonic intakes, airfoils, and other aerodynamic and propulsion parts of vehicles [1]
The purpose of the current study was to investigate the control mechanism of Nanosecond Dielectric Barrier Discharge (NS-DBD) in supersonic flow, heating and momentum transferring to the flow, and their effects on the SWBLI separation region and location of the separation shock wave
The effects of the streamwise application of NS-DBD plasma actuators were investigated and numerically analyzed in a Mach 2.5 supersonic flow passing a 14° shock generator. 3D numerical simulations were conducted for different plasma discharge lengths (L1 and L2) in the supersonic flow

Summary

Introduction

Shock Wave/Boundary Layer Interaction (SWBLI) is a key phenomenon of fluid dynamics, and its analysis is important in many supersonic and hypersonic applications, especially in various supersonic intakes, airfoils, and other aerodynamic and propulsion parts of vehicles [1] It can highly affect the performance of a propulsion system. The adverse pressure gradient caused by SWBLI sometimes induces flow separation and separation bubbles, which can lead to a reverse flow in the boundary layer, increase the boundary layer thickness, and decrease aerodynamic drag force and stagnation pressure resulting in significant performance loss of intakes. It generates nonuniform and oscillating inlet flows and results in unstarting conditions of intake. Controlling SWBLI with the approach of reducing the length of the separation region ignited strong research interest [4]

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Conclusion