Solar air heaters are widely used to save energy, especially in cases where high temperatures are not required. Among its applications are space heating, water desalination, and drying a range of products, including marine products that are used continuously. Since the thermal efficiency of solar air heaters is low, most research in investigating the types of roughness in terms of shape, size, and orientation concerning the flow direction tries to achieve an optimal arrangement and geometry of the roughness.

This article attempts to make the Nusselt number in a rectangular channel with artificial roughness and a V-shaped arrangement repeatable.

In addition, this air heater and the method of changing the parameters are investigated and optimized to the geometry of the roughness and operating parameters.

In this article, while examining solar air heaters and the roughness geometry of their absorber plates, a systematic analysis using statistical modeling method, Sobel sensitivity analysis, for important process input parameters including Reynolds number, relative groove height, relative groove pitch and angle of incidence in the geometry of artificial roughness of the absorber plate of the solar air heater, has been carried out on the behavior of the Nusselt number output responses.

This article also discusses single-objective optimization to achieve the highest Nusselt number using the Deringer statistical algorithm.