The paper presents computational fluid dynamics study of non-conventional insert vortex generator using Commercial software, to analyze the effect of vortex generator insert on heat transfer augmentation and fluid flow behavior. The study was done for Reynolds number 10000, 15000, 25000, 35000 and 45000 with working fluid as air flowing through a tube with a constant heat flux of 1000 w/m2. Current study validates the experimental results from the literature study. The heat transfer of these inserts with various geometrical arrangements viz. pitch to projected length ratio, angle of attack and height to inner diameter ratio are investigated here with the help of computational fluid dynamics software. The physical mechanism of formation and development of vortex flow from the leading edge to trailing edge of the insert is studied and it is observed that Nusselt number increases as an increment in Reynolds number. The ratio of augmented Nusselt number to smooth tube Nusselt number is found to be decreasing with increase in Reynolds number.