Evaluation of thermal and hydraulic of air flow through perforated concave delta winglet vortex generators in a rectangular channel with field synergy principle

Abstract

A compact heat exchanger can be found in air conditioning, automotive industry, chemical processing, etc. Most compact heat exchangers use gas as a heating or cooling fluid. However, gas has high thermal resistance, which affects lower heat transfer. In order to reduce thermal resistance on the gas side, the convection heat transfer coefficient is increased. One effective way to enhance the convection heat transfer coefficient is to use a vortex generator. Vortex generators are surface protrusions that are able to manipulate flow resulting in an increase in convection heat transfer coefficient by enhancing the mixture of air near the wall with the air in the main flow. Therefore, this work aims to evaluate the thermal and hydraulic characteristics of airflow through the perforated concave delta winglet vortex generator. This study was conducted on delta winglet vortex generators (DW VGs) and concave delta winglet vortex generator (CDW VGs) with the 45° angle of attack with a number of hole three-holes that applied on every vortex generator with one-line fitting, two-line fitting, and three-line fitting respectively. Results of simulation revealed that heat transfer coefficient (h) for perforated CDW VGs decrease 16.07% and pressure drop decrease 7% compare to that without hole configuration at Reynolds number of 8600. Convection heat transfer coefficient for perforated DW VGs decrease 13.76% and pressure drop decrease 5.22% compare to delta winglet without hole at Reynolds number of 8600.