An analysis of experimental data and prediction methods for two-phase frictional pressure drop and flow boiling heat transfer in micro-scale channels

Fundamental issues, mechanisms and models of flow boiling heat transfer in microscale channels

“…Quite different parametric trends of heat transfer coefficient versus quality, mass velocity, and heat flux have been reported in the literature. Figure 6 shows the various variations of heat transfer coefficient with vapor quality in the literature as illustrated by Ribatski et al [7] in their review. In most case, the heat transfer coefficient decreases with increasing the vapor quality and the hydraulic diameter, and the heat transfer coefficient increases with increasing mass velocity at a given vapor quality.…”

“…Just to show two comparisons of the experimental data obtained at similar test conditions by different researchers here as shown in Figs. 7(a) and (b) [7]. [67] while the flow boiling heat transfer coefficient keeps at nearly a constant value of 2 kW/m 2 K for the experimental data of Bang and Choo [66].…”

“…In some cases, the published results are unreasonable such as too big or too small heat transfer coefficients, some or complete wrong heat transfer behaviours and trends and correlations of various parameters and physical properties even if they have been published in journals. For instance, quite anomaly heat transfer trends are presented but they cannot be explained according to the corresponding flow boiling mechanisms in some papers although it is said that such mechanisms account for the heat transfer behaviours as detailed in a recent analysis in a comprehensive review by Ribatski et al [7]. Furthermore, some flow boiling heat transfer correlations and models were proposed by simply regressing limited experimental data at limited test parameter ranges without considering the heat transfer mechanisms.…”

“…1(b). In general, flow boiling heat transfer characteristics and mechanisms in microscale channels are quite different from those in conventional channels [3][4][5][6][7][8]. The channel size and confinement have a significant on the flow boiling characteristics, the corresponding heat transfer mechanisms and the models for predicting properly.…”

“…[1][2][3][4][5][6]. It is nowadays one of the most important research subjects in the field of heat transfer with various industrial and practical applications for the past decades [7][8][9][10][11]. For instance, as a highly efficient cooling technology, it has a lot of advantages of high heat transfer performance, chip temperature uniformity, hot spots cooling capability for cooling electronic chips and elements [4,[12][13][14][15][16].…”