Transition to the Weak-Shock Solution Around a Cone Surrounded by a Duct Induced by Laser Energy Deposition

Inducing transition from a flow state which is appeared unexpectedly in dual-solution domain to the other state is important to keep the condition of the flow in the air-intake of the ramjet engine ideal. The methods using laser energy deposition to induce this transition was proposed and numerically demonstrated. However, it has not been successfully confirmed in experiment. In this study, interaction between the thermal bubble produced by focusing pulse laser and the shock wave around the cone surrounded by a duct, which has dual-solution domain (DSD): weak-shock solution and strong-shock solution, was observed. The strong-shock at DSD transited to the weak-shock by a single bubble produced by a single laser pulse with the energy of 5.1 mJ. Interaction between the strong-shock at the condition out of DSD and series of thermal bubbles produced by repetitive laser pulse was also investigated. The shock changed to the weak-shock during the repetitive interaction with the bubbles with 30 Hz, while the bubbles with 50 Hz were jammed at the shock and not efficiently worked.