Paper Title
Investigation On Heat Transfer And Pressure Drop Of R-134a During Condensation In A Dimpled Tube

Abstract
The experimental study was conducted to investigate the condensation heat transfer and pressure drop of R-134a flowing inside a dimpled tube. The test section is a counter-flow double-tube heat exchanger, which the refrigerant flows in the inner tube and water flows in the annulus. The inner tubes are one smooth tube and one dimpled tube. The experiments are performed over a mass flux of 400 kg/m2s, heat flux of 10 kW/m2, and condensing temperature of 50 ˚C. The results show that the dimpled tube provides maximum heat transfer enhancement and pressure drop augmentation up to around 90% and 607% over the smooth tube, respectively. Index Terms - Condensation, dimpled tube, heat transfer, pressure drop.