Abstract:

Our research focuses on the study of laser-induced cavitation under various physical conditions, ranging from superheated jets to superfluid liquid helium. To observe and analyze the dynamics of cavitation bubbles, we employ ultra-high-speed video imaging techniques, capturing up to 7 million frames per second.

We primarily investigate two configurations: (1) laser-induced cavitation in liquid helium inside an optical cryostat, and (2) laser-induced cavitation in (HCP) solid helium. Additionally, we present preliminary results from two promising studies: (3) laser-induced cavitation within a highly turbulent flow in a square channel, and (4) laser-induced breakup of a cylindrical liquid jet, resulting in atomization. In the case of liquid helium-4, we manipulate the temperature within the range of 1.4 to 5.1 degrees Kelvin, which encompasses widely different thermodynamic conditions. Below the lambda point at T = 2.17 K, the liquid exhibits superfluid properties with zero viscosity. Above this point, the regular liquid helium approaches its critical point at T = 5.1 K. As a result, we have identified four distinct regimes of cavitation bubble behavior and have measured and analyzed shock velocities associated with these dynamics. In the case of solid helium (He-II), which solidifies at pressures of approximately 25 atmospheres, we observe fascinating behavior at the interface between the solid and superfluid phases. We experimentally investigate laser-induced interfacial dynamics in this system, covering temperatures between 1.2 K and 2 K and pressures ranging from the melting pressure (approximately 25 atm) to a maximum of 39 atm.

Bio:

Alghamdi Tariq was born in Tabuk city, and he studied the B.Sc. in Mechanical Engineering at Umm al-Qura University in Makkah city. He earned his M.S. (2017) in Mechanical Engineering from King Abdullah University of Science and Technology (KAUST). Now he is a Ph.D. candidate under the supervision of Prof. Sigurdur Thoroddsen in Mechanical Engineering program in the PSE division.