Extensive Parametric Study of Heat Transfer to Arrays of Oblique Impinging Jets With Phase Change

Abstract

This work presents the singleand twophase results of a parametric study investigating the performance of oblique jet arrays impinging at 45 deg on a 3.63 cm2 square copper heater surface using R245fa. It was found that the parameters that most impact heat transfer changed as the system progressed from singleto twophase flow behavior. The singlephase performance was governed by the jet geometry and the volumetric flow rate, while in the twophase region, heat transfer performance was primarily affected by the fluid conditions and the heat flux applied. A singlephase correlation was developed to capture the low heat flux response, and the twophase results were wellcorrelated by a pool boiling correlation. A new general correlation for jet impingement heat transfer with phase change is presented combining these correlations. Critical heat flux (CHF) data were compared with literature correlations and a new correlation was developed for arrays of boiling jets.