The enhancement of energetic and exergetic performance of embedded twisted rib turbulator over absorber plate of solar air heater

Abstract

Owing to present investigation, a stochastic analysis is conducted to numerically optimize the energetic and exergetic efficiencies of embedded twisted rib turbulator over absorber plate of solar air heaters (SAHs). These efficiencies are assessed taking into account temperature rise and design characteristics. The criterion in context to energy efficiency do not take into consideration the pumping force which is needed to blow the air from the duct. Therefore, estimating the energy distribution of solar air heaters becomes a difficult task when evaluating their exergetic or effective efficiency. The experimental work determined the Nu and fr correlations in the term of geometrical configurations which are considered for evaluating the thermal behavior and compared to prior findings with smooth plate. The Optimal turbulator parameters were defined by the exergetic efficiency criterion in terms of the Reynolds and insolation.Maximum improvements in energetic and exergetic efficiencies were reported as ηth=1.81;ηeff=1.79andηII=1.82 times over smooth plate for a geometric arrangement with P/e =8, α =60°, y/e = 3 and Re = 5000. The maximum differences between simulated and experimental results, when taken into account, resulted ±6%. The current methodology also tackles the methods to research novel artificial turbulator to increase the energetic and exergetic performance of a SAHs, making it feasible to develop a design plot for the turbulator parameter without having to spend a lot of money on actual trials.