Plasma-Assisted Control of Supersonic Flow over a Compression Ramp

Abstract

This study considers the effect of an electric discharge on the flow structure near a 19.4° compression ramp in Mach-2 supersonic flow. The experiments were conducted in the supersonic wind tunnel SBR-50 at the University of Notre Dame. The stagnation temperature and pressure were varied in a range of 294–600 K and 1–3 bar, respectively, to attain various Reynolds numbers ranging from 5.3 × 105 to 3.4 × 106 based on the distance between the exit of the Mach-2 nozzle and the leading edge of the ramp. Surface pressure measurements, schlieren visualization, discharge voltage and current measurements, and plasma imaging with a high-speed camera were used to evaluate the plasma control authority on the ramp pressure distribution. The plasma being generated in front of the compression ramp shifted the shock position from the ramp corner to the electrode location, forming a flow separation zone ahead of the ramp. It was found that the pressure on the compression surface reduced almost linearly with the plasma power. The ratio of pressure change to flow stagnation pressure was also an increasing function of the ratio of plasma power to enthalpy flux, indicating that the task-related plasma control effectiveness ranged from 17.5 to 25.

Rapid control of force/momentum on a model ramp by quasi-DC plasma

“…The task-related effectiveness was well above 1 in the entire test matrix and, on average, η ramp = 1.9 for ramp pressure. The effectiveness η ramp = 1.9 for 15° ramp was on the same order as a past study with 19.4° ramp case [26] with η ramp = 2.6 (converted value taking ĥ into account). However, there should be an upper limit of η ramp because the pressure decrease is limited, with P ramp not far below the freestream pressure.…”

“…In contrast to previous publications [23,26], this study is focused on transient effects of plasma-flow interaction. An imperative question to answer is: how fast could the electric discharge change the aerodynamic force/momentum relevant to a control flap on a supersonic/hypersonic transport system?…”

Numerical Investigation of the Hypersonic Inlet under Throttling with Heat Source

“…In addition, the discharge plasma energy deposition was examined in the SWBLI area on a ramp. It was demonstrated that when the discharge is activated, the force acting on the model's surface may be greatly decreased [14,15].…”