Numerical investigation of heat transfer and fluid flow characteristics of solar air heaters with multi V-shaped roughness on the energy absorber plate
Department of Chemical Engineering, Isfahan University of Technology, 84156-83111, Isfahan, Iran
Abstract
Since energy efficiency of solar air heaters is low, a large number of researches have been carried out in order to increase the heat transfer coefficients. One of the methods is roughening the side of the solarized plate which is in contact with air flow inside the duct. In the present work, Nusselt number and friction factor in rectangular duct of a solar air heater and effects of roughness geometry and operational conditions on two mentioned parameters have been studied numerically. The numerical predictions have been compared to the experimental data. By considering results of the two ducts with V-shaped roughness and relative gap width (g/e) of 0.5 and 1.0 it can be realized that heat performance of the duct with g/e equal to 1.0 is better. Besides, by creating roughness on surface of heated plate, Nusselt number and friction factor became 6.16 and 6.71 times greater than smooth duct. In the following, changing shape of roughness section from circular to triangular would lead to an increment in Nusselt number and friction factor as they were recorded 6.9 and 8.1 times greater than a smooth duct.
Sattari Najafabadi, M., & Haghshenasfard, M. (2013). Numerical investigation of heat transfer and fluid flow characteristics of solar air heaters with multi V-shaped roughness on the energy absorber plate. Farayandno, 8(42), 45-59.
MLA
Mahdi Sattari Najafabadi; Masoud Haghshenasfard. "Numerical investigation of heat transfer and fluid flow characteristics of solar air heaters with multi V-shaped roughness on the energy absorber plate". Farayandno, 8, 42, 2013, 45-59.
HARVARD
Sattari Najafabadi, M., Haghshenasfard, M. (2013). 'Numerical investigation of heat transfer and fluid flow characteristics of solar air heaters with multi V-shaped roughness on the energy absorber plate', Farayandno, 8(42), pp. 45-59.
VANCOUVER
Sattari Najafabadi, M., Haghshenasfard, M. Numerical investigation of heat transfer and fluid flow characteristics of solar air heaters with multi V-shaped roughness on the energy absorber plate. Farayandno, 2013; 8(42): 45-59.
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