The analysis of heat transfer and pressure loss for the air flow through heated cylinders with concave delta winglet vortex generators in rectangular channel: an experimental study

Abstract

Abstract The use of vortex generators to increase heat transfer in the evaporator fin-and-tube heat exchanger. Therefore the purpose of this study is to determine the effect of the use of vortex generators on increasing heat transfer coefficient and flow loss at heated tubes in rectangular channel. The experimental method is to compare the use of vortex generators and without (baseline). Vortex generators include 1, 2, 3 rows of pairs of concave delta winglet vortex generators (CDWP) and delta winglet vortex generators (DWP). Both of types of vortex generators at angle of attack (β) 15°, inlet velocity variation from 0.4 m/s - 2.0 m/s. Vortex generators were mounted on aluminum plate, heated tube with 35 watts and temperatur 38°C. Inlet, outlet and tube temperatures are measured using a thermocouple. The experimental result show that with the use of vortex generators the values of convection heat transfer coefficients and flow loss increased compared to those without vortex generators. The highest heat transfer coefficient on reynold number range 11000-12000 when using 3 pairs of concave delta winglet vortex generators are 46.76%, and 52% value pressure loss at inlet velocity 2 m/s on 3 pairs of concave delta winglet vortex generators, compared to baseline (without vortex generators).