Measurements and simulations of a channel flow powered by plasma actuators

Abstract

Experimental measurements and numerical simulations of a dielectric barrier discharge driven flow inside a finite length channel have been performed. Plasma actuators have been used to impart momentum to the flow in the near wall region, which diffuses throughout the height of the channel as it convects downstream. This momentum addition is found to be of sufficient magnitude to create an unsteady channel flow with exit velocities on the order of 1–3 m/s. Pressure and velocity measurements have been taken in order to quantify the effects of varying the number of symmetrically placed pairs of plasma actuators in the channel and the operating voltage applied to the actuators, showing a monotonic increase with respect to both parameters. Power law relationships have been determined for these measurements with respect to the operating voltage, with exponents of 2.0 for the exit velocity and of 5.6 for the maximum pressure differential. The pressure measurements also suggest that the pressure increase due to each actuator is independent of the bulk flow inside the channel. Numerical predictions also agree with the measured pressure and velocity distributions across the channel. The bulk velocity and pressure measurements allow for efficiency calculations of the plasma channel, which are shown to also fit into a power law relationship with respect to the operating voltage. The data collected show that the efficiency of these devices is low, less than 0.1%, but that it increases with a power law exponent of 4.09 to 4.35 indicating the possibility of using such channel for pumping small flows.

Noise control of subsonic cavity flows using plasma actuated receptive channels

“…This increase in pressure is balanced by the decrease in pressure before the trailing edge which implies enhanced mixing. The applied body force generates a wall jet of 5 m s −1 in quiescent conditions inside the channel which is reasonable considering recently reported experiments of plasma channel flows [8,9]. This strongly suggests that only a small momentum is required to alter the pressure in the channel.…”

Plasma channel flows: Electro-fluid dynamic jets

“…The average outlet velocity of this channel is found to be a function of number of actuators as well as the applied voltage (for a given geometry). 2,3 The classical SDBD is known to induce a suction effect upstream of the surface compliant exposed electrode. The majority flow in this suction is normal to the surface, which upon impingement on the wall changes its direction and subject to the plasma injected body force generates a very thin Glauartlike wall jet parallel to the surface.…”

Numerical Simulations Exploring Dielectric Barrier Discharge-Induced Steady and Pulsed Suction

“…4 Debiasi and Jiun-Ming's experimental work focused on investigating the effect of channel height on a pair of symmetrically placed actuators. When the walls were far away from each other the wall jets generated by the actuators were independent and similar to that seen over an exterior flat plate.…”