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

Abstract

This work presents the single-and two-phase results of a parametric study investigating the performance of oblique jet arrays impinging at 45 deg on a 3.63 cm square copper heater surface using R-245fa. It was found that the parameters that most impact heat transfer changed as the system progressed from single-to two-phase flow behavior. The single-phase peiformance was governed by the jet geometry and the volumetric flow rate, while in the two-phase region, heat transfer performance was primarily affected by the fluid conditions and the heat flux applied. A single-phase correlation was developed to capture the low heat flux response, and the two-phase results were well-correlated 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.

Low mass flux upward vertical forced flow boiling of HFE7000

“…This cubic relationship illustrates that the presence of the bubbles improves the effectiveness of the heat transfer, with higher vapour generation rates resulting in higher heat transfer coefficients. transfer mechanisms are associated with the local bubble activity and phase interactions opposed to convective influences, which is consistent with earlier convective boiling studies [16][17][18]. However, considering the boiling curves shown in Figure 9, there are some subtle differences between the different mass fluxes.…”