Numerical solution of solar air heater with triangular corrugations for indirect solar dryer: Influence of pitch and an optimized pitch of corrugation for enhanced performance

Abstract

A numerical attempt was carried out for enhancing the heat transfer phenomena of the solar air collector (SAC) by providing triangular corrugations over the SAC using the commercial software ANSYS fluent. Totally ten domains of SAC were created with different pitches (p) such as 55 (continuous corrugation), 60, 65, 70, 75, 95, 115, 135, 155 and 175 mm. The flow parameters such as velocity, temperature, turbulent kinetic energy, turbulent intensity and performance parameters such as Nusselt number (Nu), Nu ratio, friction factor (f), f ratio and thermo-hydraulic performance parameter (THPP) were estimated for both smooth and corrugated surfaces for different Reynold number (Re) of 3000 to 18000. The f and f ratio decreased continuously with Re. An increment of 199.95% in Nu was noticed at p of 55 mm and Re of 3000 compared to a smooth plate. A maximum Nu and THPP of 124.75 and 1.726, respectively, were noticed at p = 135 mm at Re = 18000 and further increase or decrease in p created low Nu and THPP and hence the optimized p was 135 mm. The numerical results were validated with previous research on a similar domain and found good agreement.