CFD Analysis and Taguchi-Based Optimization of the Thermohydraulic Performance of a Solar Air Heater Duct Baffled on a Back Plate  
[PERSON]  
1 Faculty of Heat and Refrigeration Engineering, Industrial University of Ho Chi Minh City (IUH), Ho Chi Minh City 700000, Vietnam; [EMAIL_ADDRESS] (P.B.T. ); [EMAIL_ADDRESS] (D.C.T.) 2  
[PERSON]  
1 Faculty of Heat and Refrigeration Engineering, Industrial University of Ho Chi Minh City (IUH), Ho Chi Minh City 700000, Vietnam  
2  
[PERSON]  
1 Faculty of Heat and Refrigeration Engineering, Industrial University of Ho Chi Minh City (IUH), Ho Chi Minh City 700000, Vietnam  
2  
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tested eight different unique types of baffles in rectangular channels. It is recommended that the baffle be placed in a region with a high heat flux to increase the heat transfer effectiveness. [PERSON] et al. [11] experimentally investigated an air channel with perforated plates and a rough heating surface. The results showed that heat transfer increased by 326% and pressure loss increased by 250%. [PERSON] and [PERSON] [12] experimentally studied baffles inclined in the direction of flow. There were holes with a diameter of 1.07 cm on the baffles. They reported that the Nusselt number was five times higher than that of the smooth ducts. [PERSON] et al. [13] experimentally studied and simulated single baffle and double baffle channels for comparison. They suggested a gap of 0.4 cm between the absorber plate and the baffle to prevent dead eddies. They concluded that the double baffle type gave better heat transfer. [PERSON] and [PERSON] [14] conducted a numerical study of perforated baffles perpendicular to the duct wall. The results showed that the heat transfer increased 3.1-fold and that the pressure loss increased 2.2-fold. Recently, [PERSON] et al. [15] simulated hundreds of baffle arrangements mounted on the back plate of a solar air heater. The Nusselt number increased by 3.72-fold, and the pressure loss increased by 14.47-fold. [PERSON] and [PERSON] [16] numerically studied square channels with C-shaped plates. This pattern was shown to increase eddies and perturbations at the thermal boundary layer, increasing the thermal effectiveness. More recently, [PERSON] et al. [17] experimented with 72 different baffle angles and Reynolds numbers in a duct with fixed dimensions. The results showed that the maximum thermohydraulic performance reached 1.11 at a baffle angle of 60\({}^{\circ}\) and a Reynolds number of 9000. To infer the thermohydraulic features of an obstructed air channel, a large number of test runs should be implemented in both numerical and experimental studies. Design of experiment (DOE) approaches can be employed to reduce the number of test runs, and thermophysical phenomena and optimized solutions are obtained as well. Taguchi is a DOE method developed by the Japanese engineer [PERSON]. The method is used to control product quality in industrial manufacturing processes. Currently, the Taguchi method is widely applied in different fields to reduce the number of experimental or numerical tests, but parametric studies and optimization can also be achieved [18; 19; 20; 21]. For the application of the Taguchi method to the SAH duct study, some works have been performed. [PERSON] et al. [18] studied a wide range of rib geometries, including triangles, wedges, trapezoids, and rectangles, by adopting 16 test runs from the Taguchi method. The results showed that wedge-shaped ribs achieved the best thermohydraulic performance, at 2.31. [PERSON] et al. [22] tested three geometrical parameters of a jet plate in an SAH duct.