Prediction of two-phase pressure drop and void fraction in microchannels using probabilistic flow regime mapping

Abstract

Probabilistic two-phase flow map pressure drop and void fraction models are developed for 6-port microchannels in order to provide a more accurate and common means of predicting void fraction and pressure drop.The models are developed for R134a, R410A, and air-water in 6-port microchannels at 10 o C saturation temperatures, qualities from 0 to 1, and mass fluxes varying from 50 to 300kg/m 2 -s. The probabilistic flow map models developed are found to accurately predict void fraction and pressure drop for the entire quality range and for all three fluids.

Analysis of air–water flow pattern in parallel microchannels: A visualization study

“…Downscaling of heat exchangers revealed that new flow maps were necessary to predict flow configurations in microchannels due to the increasing relevance of the surface tension (Triplett et al [8]). In addition, the liquid-gas mass density ratio was found to be important in the flow pattern determination and pressure drop prediction (Thome et al [23] and Garimella et al [24], and Jassim and Newell [13]). However, two-phase flows for practical applications occur in parallel circuit designs.…”

“…A study involving two-phase flow analysis in six-port parallel rectangular microchannels was carried out by Jassim and Newell [13]. Horizontal tests were conducted with R134a and R410A at 10°C (saturation temperature) and with air-water (at the same temperature) by Niño [14].…”

“…Each correlation is developed for the specific physical particularities of a flow pattern. However, experimental evidence (Hetsroni et al [12]; Jassim and Newell [13]; Niño [14]) indicates the simultaneous presence of distinct two-phase flow configurations in parallel microchannel circuits. The objective of this research was to determine the probability of occurrence of a specific flow arrangement according to the design flow settings at the inlet manifold.…”

Mapping of horizontal refrigerant two-phase flow patterns based on clustering of capacitive sensor signals

“…Nino et al [6] introduced the probabilistic approach in multiport microchannels. Jassim and Newell [7] applied probabilistic flow regime mapping to predict pressure drop and void fraction in microchannels. Van Rooyen et al [8] used the same approach for intermittent flows during condensation in macroscale tubes.…”

Pressure drop during horizontal flow boiling of R410A/oil mixture in 5mm and 3mm smooth tubes

“…or larger diameter tubes [1][2][3][4][5][6] as well as in 5.0 mm O.D. or smaller diameter tubes [7][8][9][10][11]. However, the reported researches on frictional pressure drop characteristics of R410A/oil mixture flow boiling inside tubes only focus on 7.0 mm O.D.…”