Laminar nanofluid flow over periodic two dimensional rectangular baffled channels

Forced convection of laminar nanofluid flow in a periodic baffled channel is numerically studied. The governing equations of the problem are continuity, momentum and energy equations which are discretized using finite volume method (FVM). The upper and lower walls of the test section are kept at a constant temperature. Two distinct baffle shapes are studied, which are diamond baffle and vertical flat plate baffle. Different half tip angles of the diamond baffle (5°, 10° and 15°) and different block ratios (BR = 0.1 H, 0.3 H and 0.5 H) for both diamond and vertical flat plate baffles are pondered. Four varied types of nanofluids are employed as working fluids which are Al ₂O₂, CuO, SiO₂, and ZnO dispersed in pure water as a base fluid. Different concentrations of nanoparticles (1% to 4%) and different diameters of nanoparticles (30 nm to 80 nm) are used. The range ofReynolds number varied from 100 to 1200. The numerical results state that with the increase in the height and the decrease in the angle of the baffle and also the increase of the volume fraction and the decrease of the nanoparticle diameter, the Nu number increases and so does the friction factor. Among all of the four studied nanofluids, SiO₂-water with 4% volume fraction and 30 nm diameter of the nanoparticles shows the highest heat transfer and thermal enhancement of the system.