CFD analysis on the spatial effect of vortex generators in concentric tube heat exchangers – A comparative study

•Heat transfer enhancement using a trapezoidal vortex generator in a Concentric Tube Heat Exchanger.•Computational Fluid Dynamics (CFD) code ANSYS Fluent is used.•Heat transfer and fluid flow analysis are conducted for various Reynolds numbers inside the tube and annular.•Results show that Vortex generators are effective in all locations and cases.•Enhancement of heat transfer ratios up to 97% and thermal enhancement factor up to 210% are obtained.