Flow and Impulse of Annular Laser-Pulse-Induced Explosions on a Sphere

摘要

A donut-sphere laser launch system has been suggested for launching a sphere capsule stably along an annularcross-sectional “donut” laser beam. In this study, the thrust and side force are numerically investigated using a simpleexplosion source model considering the beam size, explosion source energy, and axial offset between the beamand target as the parameters. It is established that the thrust, as well as the side force, is sensitive to the ratio of thelaser-beam radius to the sphere radius R*_L. The impulsive thrust force is maximum at R*_L 0.5 approximately,whereas a positive side force (i.e., recovery force) can be generated only if R*_L is greater than a critical value ofapproximately 0.8. These trends are explained with respect to shock focusing and laser ablation.