Numerical study and sensitivity analysis in the exchange of tubular heat exchangers with perforated conical rings carrying nanofluid water-aluminum oxide

In this paper, the hydrodynamic behavior and heat transfer of a turbulent nanofluid flow in a exchanger equipped with perforated conical rings are simulated numerically. Water-based fluid and aluminum oxide (Al2O3) nanoparticles with a weight percentage of zero to 5% are considered as nanoparticles that increase heat transfer. The governing equations are solved using the computational fluid dynamics method with the help of Ensys-Fluent software in the range of Reynolds number 12000-2000. After validation of the numerical solution method with the available experimental results, the effect of geometric parameters and flow characteristics such as Reynolds number number of rings used, number of holes used and volume fraction of nanoparticles on the heat transfer characteristics of the heat exchanger have been studiedThe results also show that with increasing the number of conical rings, decreasing thenumber ofholes as well as increasing the weight fraction of nanoparticles, the Nusselt number and the coefficient of friction increaseBased on the results, it is observed that the proposed conical ring can increasethe average Nusselt number by 3.5 times compared to the tube without ring. In addition, Al2O3 nanoparticles also have a favorable effect on increasing heat transfer and by increasing the volume fraction of Al2O3 nanoparticles from zero to 5%, the Nusselt numberper conical ring with three holes on it is observed to increase by about 92% in the Nusselt number.