Heat transfer mechanism in turbulent channel flow with V-tapered-baffles: Effect of convergence and divergence direction V-baffles

Solar air heaters are equipment that is utilized in a variety of applications including engineering and agriculture. Improving the transfer performance of heat exchangers is necessary to benefit from efficient energy consumption. The purpose of this work is to examine the effect of novel design V-tapered-baffles on the thermal performance of solar air heaters. The experiment was conducted with the expectation of a constant wall heat flux. In turbulent flow, air serves as the testing fluid with a Reynolds number range of 6,000 to 24,000. Two V-tapered-baffle types were employed in the experiment: convergent (C-VB) and divergent (D-VB) direction V-baffles, which were employed with fixed baffle pitch length of 60 mm and four different convergent and divergent edge baffle heights of 0, 3, 6, and 9 mm. The experimental results are compared with traditional V-baffles (T-VB) and the smooth surface channel. The investigation discovered that installing V-baffles provided a better thermal performance factor than traditional V-baffles. The important factor is that the V-baffles can reduce the friction factor by about 11–50 % compared to the traditional V-baffles under the same conditions. The maximum thermal enhancement factor values for the C-VB and D-VB were 2.19 and 2.13, respectively.