This work presents experimental results on flow-adaptive self-localization of a nanosecond (pulsed) volume discharge in a high-speed flow (up to 900 m/s) behind a shock wave within a rectangular channel of cross-section 24 \(\times \) 48 mm \(^2\) . Synchronized high-speed shadowgraphy and integrated nanosecond discharge glow capture were employed. A dielectric obstacle, 6 \(\times \) 2 \(\times \) 48 mm \(^3\) in size, was installed in the discharge section. Four distinct discharge localization regimes were identified, each dictated by the instantaneous flow field. These range from a single plasma channel in the separation region of a supersonic flow to symmetric structures in a subsonic flow, up to and including the conditions of a quiescent gas. The nanosecond discharge preferentially concentrates in low-density regions, subsequently generating intense shock-wave flows. The velocity of the semi-cylindrical blast waves can reach 1100–1200 m/s. A key finding is that the duration of the induced perturbation is found to be inversely proportional to the flow velocity. We demonstrate a mechanism for targeted energy deposition for active high-speed flow control.
