Study of methods for controlling direction and velocity of liquid jets formed during subcooled boiling

The mechanism of submerged jets generation during subcooled surface and volumetric water boiling is studied experimentally and numerically. The boiling take place near the tip of the optical fiber through which the laser radiation is supplied. It is shown that the interaction of a collapsing bubble with the end face of the optical fiber leads to the symmetry breaking of the bubble, following by the water jet generation. The jet velocity depends on the collapse rate as well as on the ratio of the maximum bubble radius reached during the inflation stage to the fiber radius and, therefore, on the laser radiation intensity. Other problem parameters affecting characteristics of the generated jets are the temperature of the surrounding liquid and the fiber radius. Experiments with two perpendicular optical fibers demonstrate vector summation of the velocities of the jets generated by each individual fiber. Presented results might contribute to the development of new operating medical technologies for laser surgical treatment of a wide range of common diseases.