In order to study the penetration depth and the spread width in a transverse jet, a flow-visualization based experimental setup was built.A phase tunable laser and CCD system was employed, and several jet to crossflow velocity ratio (r=2, 4, 8, 12, 16) were investigated.Experimental results showed that the jet to crossflow velocity ratio is the key parameter to control the penetration depth and the blending law of the jet, and that larger jet to crossflow velocity ratio resulted in much deeper penetration depth.The experimental data agreed well with the previous reports, and predicting formula was derived as the fitting equation y/rd=1.3615(x/rd)0.5608 with the correlation coefficient R=0.9996.On the other hand, the larger jet to crossflow velocity ratio is not the greater access to the spread width, and in this work, the case of r=8 obtained the largest spread width, and the spread width remains relatively large in a large penetration zone.
