The Influence of Nonideal Iso-Heat-Flux Boundary on Impinging Jet Heat Transfer Experimental Results in Modeled High Density Electronics Packaging

With much higher heat transfer rate than conventional heat transfer scheme, impinging jet received great attention from electronic heat engineers and some interested scholars. This kind of heat transfer scheme is of great possibility to become a practical solution to the cooling of high power density micro-electronics equipment. Although with simple boundary conditions, impinging jet is characterized with many complicated flow features, it is almost impossible to obtain analytical flow and heat transfer solution. As to numerical simulation, one severe obstacle is to find a proper turbulent model, because impinging jet simulation result is strongly dependent on the turbulent model adopted. So experiment becomes the most important tool to investigate the heat transfer of impinging jet. In order to obtain the heat transfer coefficient distribution of impinging surface, iso-heat-flux boundary condition was often adopted by former investigators. But ideal iso-heat-flux boundary condition is hard to realize because of the limit of material and manufacturing technology. Impinging jet with nonideal iso-heat-flux boundary condition was modeled by numerical simulation, with standard k-epsiv model as turbulent model, regardless of its strict accuracy on impinging jet. The actual heat transfer coefficient was compared with the calculated result which is based on the hypothesis of ideal iso-heat-flux boundary condition. The influence of nonideal iso-heat-flux boundary condition on calculated results was analyzed. The criterion of judging approximate ideal iso-heat-flux boundary condition is put forward which could be used as guidance for designing impinging surface in impinging jet heat transfer experiment. It can also be used to evaluate the validity of experimental results. Furthermore, the conclusion of this paper can also be applied to other heat transfer experiments with nonuniform heat transfer coefficient