Application of artificial intelligence to investigate the performance and flow pattern near staggered piece in V-ribs with aligned gaps roughness in solar air heater using relevant input parameters

Abstract

The present work findings of an experimental investigation on a rectangular duct used in a solar air heater (SAH) to increase heat transfer and frictional characteristics and improve flow near the roughness. The rough SAH surface is created by staggered V-ribs and aligned gaps. For Reynolds numbers 3000–14,000, relative gap breadth (g/e) is changed from 2 to 5, while other parameters are maintained constant: relative roughness pitch (P/e) = 10, relative staggered rib position (P'/P) = 0.4, relative staggered rib size (w/g) = 1, and relative roughness height (e/Dh) = 0.0434. The Nusselt number (Nu) and friction factor (f) are found as 2.16 and 2.73 times higher than a flat plate under the identical operating and flow conditions. The overall augmented behavior of rough SAH considering frictional characteristics is calculated in terms of Thermal enhancement factor (TEF) as 1.56. The impact of gap width on flow pattern is examined by using ANSYS Academic Research CFD 15.0. ANN outperformed GMDH. The air mass flow rate was revealed to be the most sensitive influencing element in a sensitivity analysis.