Abstract:
This experimental study explains the phenomena of secondary flow development due to change in rib perforation and the effect on improvement in THPP values due to variation in β and W/w values of a perforated multi-V rib roughness applied in double-pass parallel flow solar air heater (DPPFSAH). The fixed parameters are e/D = 0.043, p/e = 10, α = 60° and W/H = 12, and the range of variable parameters includes β = 0.0–0.31, W/w = 2–10 and Re = 2000–18,000. The optimum values of Nu/Nus, f/fs, THPP and TEIF are observed as 9.66, 12.31, 3.96 and 1.33, respectively, at β = 0.27 and W/w = 6. The maximum improvement in THPP values was 3.96 times and 1.90 times in DPPFSAH with perforation and continuous rib with a smooth plate, respectively. Double-pass SAH outperforms the single-pass SAH. Correlations for Nu and f are also developed for DPPFSAH with ± 14% and ± 7% accuracy.
