Influence of Shape, Number, and Position of Horizontal Minifins on Thermal-Hydraulic Performance of Minichannel Heat Sink Using Nanofluid

In the first part of present study, an experimental setup with constant heat flux is used to investigate the thermal performance of the water inside a horizontal triangular pin fin channel. For the sake of validation of the computational fluid dynamics (CFD) study, a simulation is conducted according to the geometry and operating conditions of the experimental work. The numerical model consists of a study that has been established based on the geometrical parameters and operating conditions similar to the experimental work. The influence of four different cross sections of minifins (shaped as square, trapezoidal, triangular, and sinusoidal) and of number of triangular minifins (1, 3, 5, 7, and 9) and their positions (in the regions of entrance, central, and terminal) on the heat transfer rate and pressure drop in a minifin minichannel heat sink are numerically investigated by a two-dimensional CFD model. The coolant is Cu-water nanofluid at a volumetric concentration of 2%. The results demonstrated that the sinusoidal minifin minichannel heat sink has the highest convective heat transfer coefficient in comparison with other shapes, while the trapezoidal minifin minichannel showed the highest thermal resistance. The highest pressure drop was observed for the triangular minifin inside minichannel. By increasing the number of fins, thermal resistance considerably decreased. Likewise, at the central and entrance positions, respectively, the highest Nusselt number and friction factor inside the minichannel was observed. This study can provide useful guidelines for the design of the cooling devices.