Vortex Breakdown Control by the Plasma Swirl Injector

Gang Li,Yong Mu,Gang Xu,Wei Du,Xi Jiang,Cunxi Liu,Jinhu Yang

doi:10.3390/app11125537

Abstract

Vortex breakdown, observed in swirling flows, is an interesting physical phenomenon relevant to a wide range of engineering applications, including aerodynamics and combustion. The concept of using a plasma swirler to control vortex breakdown was proposed and tested in this study. The effect of plasma actuation on controlling the onset and development of the vortex breakdown was captured by particle image velocimetry. Flowfield measurement results suggested that, by varying the strength of the plasma actuation, the location and size of the vortex breakdown region was controlled effectively. The plasma swirl injector offers a method for optimal control and efficient utilization of vortex breakdown. The method being proposed here may represent an attractive way of controlling vortex breakdown using a small amount of energy input, without a moving or intrusive part.

Highlights

As an active flow and combustion control device, the dielectric barrier discharge (DBD) actuator has drawn much attention for its fast response, low power consumption, and simple structure, as described by Roth et al [1]
The operation of the DBD actuator is purely electric without any moving part, which is attractive to many applications
Fujii [10] showed that actuation in burst mode was very effective for controlling flow separation at a Reynolds number of 6.3 × 104, where the three features of the flow structure, associated with flow separation control, were emphasized and guidelines for the effective use of DBD actuators were proposed

Summary

Introduction

As an active flow and combustion control device, the dielectric barrier discharge (DBD) actuator has drawn much attention for its fast response, low power consumption, and simple structure, as described by Roth et al [1]. A pressure sensitive paint technique was adopted by Kim et al [20] to investigate the effect of DBD actuation on the film cooling effectiveness of a 30◦ slot with the mainstream velocity at 10 m/s They pointed out that the improvement was not significant and that the actuator configuration should be optimized. The experimental research of Silva et al [25] demonstrated that the DBD actuators were able to reduce aerodynamic noise from slats with wind tunnel velocity of 27.4 m/s They pointed out that the control authority of the actuators tested was still poor for real flight conditions, and that further research is needed to produce more efficient plasma actuators. The plasma actuation, in affecting the onset and development of the vortex breakdown, was captured and analyzed

Layout of the Experimental Setup

Results and Discussion

Conclusions