KENTUCKY UNIV LEXINGTON DEPT OF MECHANICAL ENGINEERING
Experiments were conducted to study the free expansion blow-down behavior of cryogens. Visualization of the phenomena and determination of the final state of LN2 during free expansion were the main purposes of the study. Results presented show the effect of nozzle size, upstream pressure and downstream pressure. The second part of the study details the experiments conducted to study the heat transfer characteristics during spray cooling with LN2. Four different nozzles at various pressures were used to study the variation in spray cooling heat transfer. Effect of nozzle and flow rate on the critical heat flux and overall heat transfer characteristics are presented. Finally an experiment designed to study the LN2 pool boiling heat transfer from discrete sources in a confined space is described. Blow-down, Supercritical hydrogen, Cryogens, Spray cooling, Jet impingement, Free expansion, Pool boiling.