Thermo-Hydraulic Performance Evaluation of Inclined Vortex Generators

Abstract

In the present study, a commercial finite volume package ANSYS FLUENT 14.5 has been used to determine thermo-hydraulic performance of two different vortex generator (VG) configurations, namely, flow-up and flow-down, located in triangular ducts. A comprehensive literature survey on flow-up and flow-down configurations has shown that there are completely opposite results obtained in terms of performance of the two configurations. In some studies, flow-up configuration showed better performance characteristics over flow-down configuration while in other studies flow-down configuration was found better. This has been motivated the present authors to make a study covering the two VG configurations to find out which one has a better performance over the other one. Therefore flow and thermal fields together with the secondary flow induced by the two VG configurations have been analyzed extensively. The geometry comprised of double row of VGs located on the slant surfaces of equilateral triangular ducts. The angle of inclination of the VGs made with the flow direction is 30°. The results show that flow-down configuration has a 40.65% higher thermo-hydraulic performance over the flow-up configuration for Re=5000. It is also shown that the heat is transferred at a further downstream distance allowing in a reduction in the number of VGs to be used in of flow down case.