Abstract
The relationship between the momentum-coupling coefficient C and the nozzle cone-angle of laser pulse-jets is investigated using Computational Fluid Dynamics. Temporal variations of thrust and pressure fields inside and outside conical nozzles are obtained, and computed C is compared with measured one. As a result, the computation well reproduces the measured C and its decreasing tendency with the nozzle cone-angle. The reason of this tendency is explained in relation to two-dimensional flow characteristics in its air-refresh process. In addition, it is suggested that the laser pulse width should be short enough that the laser-heated region can be smaller than the optimum nozzle size.
