the steady state effect of vertical fins is assessed on a photovoltaic/thermal solar air heater having a double pass configuration in which fins are placed in the lower channel perpendicular to the direction ofair flow. air passes through the upper channel of the air heater and before passing in the opposite direction through the lower channel. the effects of design, climatic and operating para...

in this research a flat plate solar air collector was investigated under direct solar radiation consisted of a slatted glass cover, perforated absorber aluminum sheets (porosity 0.0177, 0.0314 and absorber thickness of 2.5 mm). the effect of porosity on absorber efficiency of collector was evaluated. six levels of air mass flow rates (0.0056 to 0.0385 kg m-2 s-1) were adopted.average solar ener...

The problem under investigation contains a computational simulation of a specific heat exchanger with complex geometry fins. The problem solved is potentially interesting for researchers and engineers working on solar collectors and aerospace industry. It is known that heat transfer enhancement can be achieved by creating longitudinal vortices in the flow. These vortices can be generated by arc...

outdoor experiments on a once-through single glazed solar air heater with perforated metal absorber plate were conducted to determine the practical effect of absorber plate porosity as well as suction air flow rate on the collector thermal efficiency and its total pressure drop. three aluminum absorber plates were made perforated by drilling circular holes with different diameter/pitch ratios i...

a mixed solar dryer with a specific mechanism to vary the tilted angle of collector, is utilized to fulfill all tests. the efficiency of the dryers is low because of various reasons such as heat loss of air in an open flow circuit. getting air back toward the air inlet of dryer can increase the efficiency of dryer and decrease drying process period. a new mechanism considered for dryer which co...

The influence of recycling on double-pass solar air collectors with welding of the V-corrugated absorber has been studied experimentally and theoretically. Welding the V-corrugated absorber and the recycle-effect concept to the solar air collector was proposed to strengthen the convective heat-transfer coefficient due to turbulence promotion. Both the recycle effect and the V-corrugated absorbe...

drying is a high energy consuming process. solar drying is one of the most popular methods for dehydration of agricultural products. in the present study, the performance of a forced convection solar dryer equipped with recycling air system and desiccant chamber was investigated. the solar dryer is comprised of solar collector, drying chamber, silica jell desiccant chamber, air ducts, fan and m...

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