Numerical simulation is to be carried out to study the heat transfer and fluid flow in the plate-fin and tube heat exchangers with different shaped vortex generators mounted behind the tubes. Three different span angles a (a = 30°, 45° and 60°) for three different shaped (aerofoil, elliptical and semi-circular) vortex generators are to be investigate in detail for the Reynolds number ranging from 400 to 3000. Numerical Simulation is to perform by a computational fluid dynamics for the heat transfer and fluid flow for the temperature distribution and local flow structure. The comparisons of heat transfer enhancement with flat tube-fin element with and without vortex generator enhancement under different shaped vortex generators are to carry out and optimized shape for heat transfer is to be verified. The proposed heat transfer enhancement technique is able to generate longitudinal vortices and to improve the heat transfer performance in the wake regions. A reduction in fin area may be obtained if vortex generators embedded fins are used in place of plain fins. The proposed heat transfer enhancement technique may produce less pressure drop with high heat transfer Fluid flow and hear transfer over 3-row plate-fin and tube heat exchangers with and without a pair different shaped vortex generators are to be studied using Computational fluid dynamics. The conjugated convective heat transfers in the flow field and heat conduction in the fins will be considered. Study to be carried out for the flow and behavior of vortex generators in the wake re-circulation zone. The span angle is to be increased, the strength of the longitudinal vortex is intensified and both the Colburn and friction factors are to be increased. The study of arrangement of span angle is to be carried out and relative heat transfer rate is to be measured for Reynolds number 400 to 3000.