Investigation on the submerged liquid jet arrays impingement cooling

The influence of jet arrays on heat transfer was experimentally and numerically studied. Four different arrays were tested using deionized water as the working liquid. The jets diameters ranged from 0.5 mm to 2.0 mm and the Reynolds number varied from 3500 to 12,000. Spacing of 3.5 mm between adjacent jets and 100 jets were used for the 0.5 mm diameter jet arrays while spacing of 7.0 mm between adjacent jets and 25 jets were employed for other jet arrays. The dimensionless parameter H/d_n was fixed to 3.36. With an average impingement velocity of 11 m/s and the temperature of the inlet liquid being 20 °C, a maximum surface heat flux of 270 W/cm² was achieved using 1.0 mm diameter jet arrays. The average temperature of the heater surface reached 75.73 °C. The experimental data were corrected using four independent dimensionless parameters. With the application of the correction, the optimal main geometrical parameters of the jet arrays could be obtained. Based on the experimental setup, analysis models were established. The influences of dimensionless parameters H/d_n and s/d_n were studied. Studies of the Nusselt number in those models showed that jets impingement cooling established best with fixed s/d_n of 7 and H/d_n of 5.0.