Numerical investigation of convective heat transfer characteristics of circular and oval tube banks with vortex generators

The present work represents a 3-D numerical investigation of forced convection heat transfer over circular and oval tube banks with longitudinal vortex generators (LVGs) for flow through a fin-and-tube heat exchanger. The thermo-hydraulic performance parameters are studied numerically using computational fluid dynamics (CFD) tool. It is found that within the range of Reynolds number (500-850) studied, the degree of heat transfer enhancement is greatly influenced by the tube shape. Heat transfer increases by 13 % when the angle of attack is varied from 15° to 25°, with a corresponding pressure drop of 40 % and 62 % for the oval tubes and circular tubes, respectively. The effect of the aspect ratio of the oval tubes is observed to be very significant. Several other performance parameters of the oval and circular tube banks with vortex generators under the same operating conditions are compared with a focus on finding an optimal configuration.