Recent Studies on the Forced Convection of Nano-Fluids in Channels and Tubes: A Comprehensive Review

Nowadays, nanoparticles have been widely applied in liquids due to their great impact on the growth rate of heat transfer as well as the solutions for the problems raised from the use of particles larger than nano in various currents. Therefore, in this article, an attempt has been made to study the research carried out in the field of forced heat transfer of nanofluids inside channels and pipes. In this way, the authors are reviewing articles starting from 2018 for channels and 2017 for tubes/pipes. All the articles that are in the above category have been studied from different viewpoints. In this article, first, the type of flow and the relations used in this field are introduced and by comparing the published articles in terms of methodology, type and size of nanoparticles, volumetric ratios of nanoparticles, flow conditions, etc., so that the effect of these parameters can be studied on heat transfer. The following is a statistical study of articles in this field, which includes all articles published from the beginning to the present, which have dealt with this issue in theory, numerical and experimental. As a result, it becomes clear that the special geometric properties of channels and pipes, the insertion of obstacles in the flow path with special conditions and characteristics, as well as the boundary conditions defined in recent studies have considerable influence on the growth of heat transfer rate and the improvement of system efficiency.