Analytical investigation of exergetic performance on jet impingement solar air heater with multiple arc protrusion obstacles

In this present work, an exergetic efficiency of the solar air heater (SAH) with jet impingement on multiple arc protrusion roughened absorber plate is analytically studied. It is examined out for roughness parameters of relative width ratio (W-P/W-AP) of 1-5, relative height ratio (e(P)/d(P)) of 0.5-2, relative pitch ratio (P-P/e(P)) of 8-12 and angle of arc ((a)) of 35 degrees-75 degrees. Performance of SAH based on the second law has been effectively assessed by enumerating the useful exergy gain, irreversibility and losses occurred due to the inefficiency of the system components. Results indicate that the exergetic efficiency has been enhanced by 56.8%. Effects of roughness parameters on exergetic efficiency have been presented based on Reynolds number and temperature rise parameter. The optimized values of roughness parameters are identified, and the maximum exergetic efficiency is found to be 10.5%. Maximum exergetic destruction caused due to temperature difference between absorber plate and Sun is 65.2% at optimized conditions. In order to identify the optimum values of roughness parameters to attain the required temperature rise with maximum exergetic efficiency, design plots have been developed.