THERMAL SCIENCE

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CFD analysis of a v-rib with gap roughened solar air heater

ABSTRACT
A computational fluid dynamics (CFD) analysis of a solar air heater has been carried out using v-shaped ribs as artificial roughness on the absorber plate. The relative roughness pitch (P/e=6-12), Reynolds number (Re=3800-18000), and relative roughness height (e/D=0.042), angle of attack (α=30°-75°) have been selected as design variables of V-shaped rib for analysis. ANSYS FLUENT 15.0 with renormalization group k-ε turbulence model is selected for the analysis of computational domain of solar air heater. The enhancement of Nusselt number and friction factor with Reynolds number for different values of a relative roughness pitch (P/e) are presented and discussed by CFD analysis. The effect of angle of attack (α) and Reynolds number on enhancement of Nusselt number (Nu) and friction factor (f) is also presented. The optimum value of rib configuration based on constant pumping power requirement has been derived using thermo-hydraulic performance parameter and has been found maximum at angle of attack of 60° and P/e = 10.
KEYWORDS
PAPER SUBMITTED: 2016-08-31
PAPER REVISED: 2016-10-27
PAPER ACCEPTED: 2017-01-07
PUBLISHED ONLINE: 2017-02-12
DOI REFERENCE: https://doi.org/10.2298/TSCI160831010R
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