Abstract
The behavior of ring vortices and the impingement heat transfer of the pulsating axisymmetric jet were studied experimentally by using water jet and air jet, respectively. The growth of ring vortices was visualized by the dye injection on condition that F=1〜5Hz and A=0.075〜0.194. The heat transfer coefficients at the stagnation point were measured on condition that St=0.5〜0.8 and A=0.3〜0.7. It was observed that the frequency of ring vortices was equal to the pulsation frequency. And the growth of ring vortices and the velocity fluctuation in the pulsating jet depended on the pulsation conditions. The heat transfer coefficients were therefore varied uniquely by the pulsation frequency and the amplitude ratio.
