Author(s)

Sakira Uno¹, Hiroshi Fukuoka^2*, Atsushi Suda², Ikurou Umezu³

¹Faculty of Advanced Engineering, National Institute of Technology, Nara College, Yamatokoriyama, Nara, Japan.
²Department of Mechanical Engineering, National Institute of Technology, Nara College, Yamatokoriyama, Nara, Japan.
³Department of Physics, Konan University, Kobe, Japan.

Double pulsed-laser-ablation is a promising method to prepare nanoparticle composites. The backward movement of the plume after the collision with counter-propagating shock wave has been observed in experiments. In the present study, collision dynamics of the oppositely injected Si and Ge jets into a He background gas was numerically calculated as a simulation for double pulsed-laser-ablation. The experimentally observed backward movement was reproduced. The effect of distance between two jet exits on the distance of backward movement of the jet, B_L, after the collision with the counter-propagating shock front was calculated to discuss the collision dynamics and to optimize the target distance for the experiment. We found that B_L does not decrease monotonically with increasing distance between two jet exits, but has a maximum value at a certain distance. This behavior is discussed by calculating the expansion dynamics of an individual jet. Shock wave grows with time at the initial stage of the jet expansion and then attenuates; the density just behind the shock front for individual jet has a maximum value at a certain time and position. B_L has a maximum value when the densities just behind the shock fronts for the individual jets have maximum values. This result is important for designing the appropriate distance between the two jet exits, i.e., the distance between the targets of double pulsed-laser-ablation.

Collision of Supersonic Jets, Shock Wave, Computational Fluid Dynamics, Laser Ablation

Uno, S. , Fukuoka, H. , Suda, A. and Umezu, I. (2023) Study on Collision Process of Opposing Unsteady Supersonic Jets and Shock Waves. Open Journal of Fluid Dynamics, 13, 104-112. doi: 10.4236/ojfd.2023.132008.