Triggering Shock Wave Positions by Patterned Energy Deposition

Abstract

The problem considered in this work is shock wave (SW) positioning control in shock-dominated flows. Experiments are conducted to investigate the triggering effect of patterned near-surface electrical discharges on SW reflection from plane walls. In the wind tunnel, M=4, P0 = 4 bar, a solid wedge SW generator is mounted on the upper wall. Q-DC filamentary electrical discharges were arranged on the opposite wall, so that the SW from the wedge impinged on the plasma filaments that are arranged flow-wise in either a row of three or a single central filament. Within the supersonic flow, narrow subsonic areas are actuated by electrical discharge thermal deposition, resulting in pressure redistribution, which, in turn, relocates the reflection of impinging SW to a predefined position. Mie scattering, schlieren imaging, and wall pressure measurements are used to explore the details of plasma-SW interaction. Using Mie scattering, the three-dimensional shape of the SW structure is mapped both before and after electrical discharge activation. Plasma-based triggering mechanisms are described in terms of the physical principles of flow control and a criterion for determining the effectiveness of the flowfield control.

The Use of Spatially Multi-Component Plasma Structures and Combined Energy Deposition for High-Speed Flow Control: A Selective Review

“…Thus, the approach shows promising results for controlling both SWBLI and shock-dominated flows. , in [49], continued the study in works by S. Leonov et al [46][47][48] and considered the problem of SW/BSW control in shock-containing flows. The triggering effect of patterned near-surface electrical discharges on the reflection SW was studied experimentally.…”

“…In [46][47][48][49][50][51], S. Leonov's group considered the problem of SWBLI and suppression of the different types of SWs by a streaming plasma array. The experimental results on the damping of the oblique shock wave reflection by a filamentary plasma and the pressure distribution on the wall in a supersonic airflow of Mach number M ∞ = 2 moving along a channel are presented by S. Leonov et al in [46][47][48].…”

“…Simplified criteria for the efficiency of the plasma control of the SW position are formulated as a function of the critical plasma temperature and the flow Mach number (Figure 6). P. Andrews et al,in [49], continued the study in works by S. Leonov et al [46][47][48] and considered the problem of SW/BSW control in shock-containing flows. The triggering effect of patterned near-surface electrical discharges on the reflection SW was studied experimentally.…”

“…(a) Baseline, plasma off; (b) plasma on, heat source power 𝑊 = 8 kW [47]. Reprint by Creative Commons Attribution (CC BY) 3.0 license.. P. Andrews et al, in[49], continued the study in works by S. Leonov et al[46][47][48] and considered the problem of SW/BSW control in shock-containing flows. The triggering effect of patterned near-surface electrical discharges on the reflection SW was studied experimentally.…”

The Use of Spatially Multi-Component Plasma Structures and Combined Energy Deposition for High-Speed Flow Control. A Selective Review

“…In [46][47][48][49][50][51] the S. Leonov's group considered the problem of SWBLI and suppression of the different types of SWs by a streaming plasma array. The suppression of the reflected oblique shock wave by a filamentary plasma and the pressure distribution on the wall in a supersonic airflow of the Mach number M∞=2 moving along a channel are obtained by S. Leonov et al in [46][47][48].…”