Hypersonic Flow over a Cylinder with a Nanosecond Pulse Electrical Discharge

Abstract

A computational study of Mach 5 airflow over a cylinder with a dielectric barrier discharge actuator was performed. The actuator was pulsed at nanosecond time scales and it rapidly added thermal energy to the flow, creating a shock wave that traveled away from the pulse source. As the shock wave traveled upstream, it interacted with the standing bow shock, and temporarily increased the bow shock standoff distance. This phenomenon was also observed experimentally through phase-locked schlieren photography. This paper aims to reproduce flow phenomena observed in the experiment using high-fidelity computations in order to provide additional insight into the shock-shock interaction, and subsequent effect on the cylinder, through a reduced-order phenomenological model of the actuator. A three-dimensional simulation of the experiment was able to accurately capture the complex cylinder/ tunnel-sidewall interaction, and to replicate the changes in the flow produced by the nanosecond dielectric barrier discharge. The results show that the device was very effective at moving the standing bow shock for a minimal energy budget.

Nanosecond-pulsed dielectric barrier discharge-based plasma-assisted anti-icing: modeling and mechanism analysis

“…The pressure wave then decays soon afterwards. At this level of pressure perturbation, the velocity change ∆u on a tiny water drop can be simply calculated by ∆u = F∆t/m = ∆PS∆t/m (13) where the pressure increase ∆P = 2000 pa, the cross-section of the water drop S = π(MVD/2) 2 ≈ 1.56 • 10 −10 m 2 , the mass of water drop m = ρ • 3π(MVD/2) 3 /4 = 4.6 • 10 −12 kg, and the affecting time calculated from the pressure-affected region ∆t = 10 −4 [m]/65[m/s] = 1.5 • 10 −6 s. Substituting into equation ( 13) we get ∆u ≈ 0.1 m s −1 , which is only 0.15% of the water drop velocity. Thus the impact of the 'microshockwave' could be neglected in anti-icing applications.…”

“…In the case of nanosecond-pulsed SDBD (nSDBD), the ionic wind is no longer observed; instead a micro perturbation wave will be generated from the edge of the electrode due to fast release of the energy stored in the electronically excited states [5][6][7][8]. The features of ionic wind generation and fast gas heating of SDBDs have been studied and utilized in applications such as plasma-assisted flow control [9][10][11][12][13][14] and plasma-assisted ignition/combustion by different groups since the early 2000s.…”

Numerical Investigation on the Effects of Chemical Reactions on the Discharge Characteristics and Energy Balance of a Nanosecond Repetitive Pulsed Dielectric Barrier Discharge

“…However, it contributes no more than 10% of the total energy released at the relatively high reduced field (E/N > 200 Td) [38]. Therefore, a kinetic model is further reduced based on R50 by excluding all the vibrational excited nitrogen species N 2 (υ = [1][2][3][4][5][6][7][8]. It is denoted as R42.…”

“…It can introduce wide-band perturbations of temperature, pressure, and density, which can trigger instabilities in the shear flows. NS-DBD plasma actuators can be applied in the high-speed flow controls [1,2].…”

Joule heating flow control methods for high-speed flows

“…A study carried out later by Bisek et al. 31 presented a comparison between experimental and numerical results for a configuration similar to Nishihara et al 30 Both 2D and 3D simulations were carried out using an aerothermodynamic Navier-Stokes code. A phenomenological model of dissipative heating was used for the ns-DBD, meaning that the numerical model of the actuator was based on empirical observations and assumptions.…”