Experimental study of the hydrodynamic and heat transfer of free liquid jet impinging a flat circular heated disk

This study concerns the hydrodynamic and the thermal characteristics of the free liquid jet impinged a heated disk. The thin liquid layer depth is measured along the axial and the radial directions using the laser induced fluorescence and image processing. The experimental results are compared to the laminar and turbulent theories of Watson [E.J. Watson, The radial spread of a liquid over horizontal plane, J. Fluid Mech. 20 (1964) 481-500]. The influence of the temperature and the liquid flow rate on the structure of the impingement jet is studied. The profiles of the axial and the radial velocities are measured along the flow. The hydraulic jump radius is measured for different Reynolds number and temperature of the flow. The heat transfer coefficient is measured in the stagnation zone and the experimental values are compared to the experimental data of Jiji and Dagan [L.M. Jiji, Z. Dagan, Experimental investigation of single-phase multijet impingement cooling of an array of microelectronic heat sources, in: Cooling Technology for Electronic Equipment, International Symposium Honolul U HA, 1988, pp. 333-350]. The distribution of the local heat transfer coefficient is determined by solving the inverse heat conduction problem. (C) 2005 Elsevier Ltd. All rights reserved.