抄録
Gas flows in unsteady jets were calculated from a large eddy simulation (LES). Based on obtained results, the effects of velocity conditions at a nozzle exit on penetration length and jet radius were clarified. Furthermore, it was shown that vortex generation in a shear region and a jet-tip was enhanced by adding perturbation to a nozzle-exit, which promoted an entrainment into a jet and turbulent diffusion of momentum.