Exergetic performance evaluation of solar air heater having arc shape oriented protrusions as roughness element

• Analytical model is used to estimate exergetic performance using developed correlations.
• Exergetic performance of a solar air heater was estimated analytically for protrusion shaped roughness elements.
• Design plots were also prepared for protrusion shaped roughness geometry.

Solar energy is a clean, abundant and easily available source of energy. Thermal performance of solar air heater does not take into account the energy loss due to friction for propelling air through the duct. In this work an attempt has been made to evaluate exergetic efficiency of roughened solar air heater duct provided with protrusions arranged in arc fashion over the absorber plate. The exergetic efficiency of a solar air heater was calculated analytically using developed correlations and the results were compared with that of a smooth flat-plate solar air heater. Design plots were also prepared in order to facilitate the designer for designing such type of roughened solar air heater within the investigated range of system and operating parameters.