CFD Analysis to Study Effect of Circular Vortex Generator Placed in Inlet Section to Investigate Heat Transfer Aspects of Solar Air Heater

Abstract

CFD analysis of 2-dimensional artificially roughened solar air heater duct with additional circular vortex generator, inserted in inlet section is carried out. Circular transverse ribs on the absorber plate are placed as usual. The analysis is done to investigate the effect of inserting additional vortex generator on the heat transfer and flow friction characteristics inside the solar air heater duct. This investigation covers relative roughness pitch in the range of 10 ≤ P/e ≤ 25 and relevant Reynolds numbers in the range of 3800 ≤ Re ≤ 18000. Relative roughness height (e/D) is kept constant as 0.03 for analysis. The turbulence created due to additional circular vortex generator increases the heat transfer rate and at the same time there is also increase in friction factor values. For combined arrangement of ribs and vortex generator, maximum Nusselt number is found to be 2.05 times that of the smooth duct. The enhancement in Nusselt number with ribs and additional vortex generator is found to be 1.06 times that of duct using ribs alone. The maximum increase in friction factor with ribs and circular vortex generator is found to be 2.91 times that of the smooth duct. Friction factor in a combined arrangement is 1.114 times that in a duct with ribs alone on the absorber plate. The augmentation in Thermal Enhancement Factor (TEF) with vortex generator in inlet section is found to be 1.06 times more than with circular ribs alone on the absorber plate.

Thermal Hydraulic Performance in a Solar Air Heater Channel with Multi V-Type Perforated Baffles

“…The values of Reynolds number, Nusselt number, average Nusselt number, friction factor and thermal-hydraulic performance have been calculated using the following equations [15,17,[19][20][21][22][23]:…”

“…However, only a few investigations are available those are based on CFD approaches [23][24][25][26][27][28][29][30][31][32][33][34]. Gawande et al [23] conducted a numerical study on the effect of the transverse circular vortex type generator in an air channel. It was observed that the performance of the transverse circular vortex type generator in the channel was better than that of the smooth wall channel.…”

Application of Multidisciplinary Systems‐of‐Systems Optimization to an Aircraft Design Problem

“…This is a simplified version of the vortex system generated close to the wing tips, but the reader is reminded that the Augmented Betz method is also capable of producing more complex, multivortex systems. The methodology of generating this system is similar to “effect‐based” models used in Gawande, Dhoble, and Zodpe [], Waithe [], and Lane []. More complex immersed boundary‐based solvers may be used in the future.…”

Experimental and CFD-based thermal performance prediction of solar air heater provided with right-angle triangular rib as artificial roughness

“…To achieve higher accuracy, the convergence criteria between two consecutive iterations is set to be relative deviation less than 10 -6 for energy equation and less than 10 -3 for solution in velocity and the continuity equation. The above discussed method of investigation has been validated in the author's previous work [44].…”