An experimental investigation on the effect of laser energy deposition in an over-expanded jet
Year: 2025
Type: article
Abstract: This experimental investigation focuses on understanding the influence of perturbations due to short-duration energy deposition on the shock train structure and flow dynamics in an axisymmetric over-expanded Mach 2.52 jet. The flow is perturbed by localized laser-induced breakdown at various locations within the jet, creating a shock wave and a high-temperature plasma zone in the shock train. A high-speed self-aligning focusing schlieren system is used to visualize the flow structure variations by measuring the distance to the first shock reflection point to characterize the shock train dynamics and the flow structure recovery process. The response of the jet flow is similar for cases with the perturbation at the nozzle exit and the pre-reflection point across a range of jet total pressures but the response is qualitatively different when the perturbation occurs downstream of the first shock reflection in the jet, with the flow structures being forced upstream towards the nozzle. The frequency of the oscillations of the shock height is found to be the same for all cases, approximately 10 kHz, independent of the jet total pressure, laser energy, and deposition location. The oscillations reduce in magnitude over time, and the damping ratio for cases with the energy deposition at the pre-reflection point and nozzle exit is found to be nearly constant with respect to jet total pressure and deposition energy, whereas it is dependent on the jet chamber pressure for the post-reflection case.
Source: Experiments in Fluids
Authors: S. Syam, Gauresh Raj Jassal, Bryan E. Schmidt
Institution: Case Western Reserve University
Language: English
Subfield: Aerospace Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $2,590
OpenAlex ID: W4409164165