Experimental Investigation of Heat and Fluid Flow Characteristics on Expanded Metal Mesh Roughened Solar Collector

Solar air heater is used for agricultural grain products drier, curing of industrial and other systems requiring low grade thermal energy. Their usefulness quantitative energy collections has been limited. This because efficiency with primarily as a result convective heat transfer coefficient, between the absorber plate leading to higher temperature. results greater losses. Experimental investigation conducted study enhancement by using small diameter wire ribs on solar duct, roughened wall exposed glazing side while remaining 3 walls were insulated. The relative roughness height (e/Dh) 0.0135 - 0.0406, pitch (p/e) 10 20, rib 0.5 1.5 mm, expanded metal mesh (L/e) 25 75, Short way (S/e) 15 45, angle attack 45° inclined configuration, duct aspect ratio 12 flow rate corresponds Reynolds number 2,000 18,000. It found that coefficient could be improved factor up 2.2 friction had increase 1.2 times smooth duct. emphasized secondary rolling along responsible rates. Thermal increased from 50.58 65.75 %. Finally, correlation developed both Nusselt sigma plot software, which can selected designer given operating condition.
 HIGHLIGHTS
 
 At moment are spoiled due poor dryer
 A collector designed, manufactured experimental test conducted
 An efficient dryer obtained
 GRAPHICAL ABSTRACT