EXPERIMENTAL MEASUREMENTS AND COMPUTATIONAL MODELING FOR THE SPRAY COOLING OF A STEEL PLATE NEAR THE LEIDENFROST TEMPERATURE

Experimental studies and numerical simulations were conducted to reveal the heat transfer mechanism of impacting water mist on metal surfaces heated temperatures ranging from nucleate to film boiling regime. The test conditions of water mist cover the variations of air velocity from 0 to 50 m/sec, liquid mass flux from 0 to 7.67 kg/m(2)sec, and surface temperature of stainless steel between 525 degrees C and 500 degrees C. Local heat transfer coefficient and radial heat transfer distributions were measured at different air velocities and liquid mass fluxes. Experimental studies and computer simulations show that heat transfer coefficient increases not only with the air velocity but also with the liquid mass flux at the stagnation point. In addition, a small amount of water added in the impacting air jet, the heat transfer is significantly increased. For dilute spray, the mist heat transfer coefficient increases almost linear with the water mass flux. Results of computational study were compared against experimental data at atmospheric conditions, and the numerical model showed good accordance with the test data