TY - JOUR
TI - The CFD studies on the influence of un-wetted area on the heat transfer performance of the horizontal tube falling film evaporation
AU - Balaji Dilli
AU - Velraj Ramalingam
AU - Ramanamurthy Malavarappu
JN - Thermal Science
PY - 2022
VL - 26
IS - 1
SP - 25
EP - 35
PT - Article
AB - This paper discusses about the effect of un-wetted area of tube on the heat transfer performance of horizontal tube falling film evaporation. A 2-D CFD model was developed to perform simulations and investigate the output and validated them with published data available in the literature. In the present study the volume of fluid method is used to track the boundary of the liquid vapour from the contours of volume fraction. Effect of varying tube wall temperature or wall super heat (6-11°C) on un-wetted area, heat transfer coefficients, and mass transfer coefficients of the circular tube were obtained from the simulation model and the results were analysed and reasons were identified and discussed here. The threshold value of wall super heat above which phase change occurs between liquid film and tube surface is identified as 6°C. Also it is noted that mass transfer rate increases and then decreases with increase of wall super heat and heat transfer coefficient showed declining trend.