A double pipe heat exchanger, in its simplest form is just one pipe inside another larger pipe. One fluid flows through the inside pipe and the other flows through the annulus between the two pipes. The wall of the inner pipe is the heat transfer surface. The pipes are usually doubled, in order to make the overall unit more compact. In this work the review on various researches have been done for the enhancement of heat transfer in double pipe heat exchanger and the analysis of the survey is shown in this research. It can observed that the extended surface play an important role in the enhancement of heat transfer. In this work the extended surface added in the inner tube and the model will be generated in the CFD, the model will be meshed and the results analysed in the Post CFD.