Andriyanto Setyawan^a,*

Frontiers in Heat and Mass Transfer, Vol.14, pp. 1-6, 2020, DOI:10.5098/hmt.14.22

Abstract In this paper, the effect of evaporating temperature on the void fraction and flow pattern of R290 in an evaporator of air conditioning unit has been studied. The analysis was carried out for evaporator diameter of 7.9 mm and 6.3 mm and cooling capacity of 2.64 kW and 5.28 kW. The analysis was conducted at evaporating temperature of -20°C to +5°C with an increment of 5°C. At the inlet of evaporator, the void fraction ranges from 0.932 to 0.984, whereas at the outlet the void fraction is 1. Testing the void fraction by using 3 available correlations gives the good… More >

Li Lei¹, Jun An¹, Fushun Liang¹, Cheng Cheng¹, Naixiang Zhou², Yanhong Ning³, Jingzhi Zhang^1,4,*

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.6, pp. 1037-1048, 2021, DOI:10.32604/fdmp.2021.016081

Abstract The flow patterns and the void fraction related to a gas-liquid two-phase flow in a small channel are experimentally studied. The test channel is a transparent quartz glass circular channel with an inner diameter of 6.68 mm. The working fluids are air and water and their superficial velocities range from 0.014 to 8.127 m/s and from 0.0238 to 0.556 m/s, respectively. The void fraction is determined using the flow pattern images captured by a high-speed camera, while quick closing valves are used for verification. Four flow patterns are analyzed in experiments: slug flow, bubbly flow, annular flow and stratified flow.… More >