Turbulent Nanofluid Flow Over Periodic Rib-Grooved Channels

Abstract

In this paper, the effects of using different rib-groove shapes of triangular, square and arc, different geometrical parameters and also different types of nanofluids including and on the thermal and hydraulic behavior of flow in a horizontal rib-grooved channel are numerically investigated. The finite volume method (FVM) is applied to solve the two dimensional governing and energy equations. Constant heat flux was imposed on the channel walls. The effects of nanoparticle diameter in the range of 30-70nm, nanoparticle volume concentration in the range of 1-4%, and also Reynolds numbers varying from 30,000 to 50,000 were examined in this study. The performance of rib-grooved channel was evaluated in terms of average Nusselt number, friction coefficient and performance index. The results revealed that rectangular rib-rectangular groove shows the best performance having the highest performance evaluation criterion (PEC). The results also indicated that using nanofluid flow in grooved channels could provide a significant increase in heat transfer and thermal performance with negligible increase in friction. The SiO2-water nanofluid provides highest Nusselt number among all types studied. It is also observed that increasing the nanoparticles volume fraction and Reynolds number enhanced the Nusselt number while increasing nanoparticles diameter decreased it.

A survey of practical equations for prediction of effective thermal conductivity of spherical-particle nanofluids

“…Combining Eqs. (1) and (2) it is apparent that the enhancement predicted by Corcione's equation also increases with decreasing particle size but in proportion to d p −0.4 . This phenomenon, although not predicted by classical Maxwellian theory [3], appears to be related to the increased relative surface area of particles with decreasing particle size.…”

“…From a practical point of view it is convenient to model this enhancement as an increase in effective thermal conductivity of the fluid (e.g. [1,2]) . The earliest existing equation useful for predicting the effective thermal conductivity of such fluids was derived by Maxwell towards the end of the 19th century [3].…”

MODELLING AND SIMULATION OF Au-WATER NANOFLUID FLOW IN WAVY CHANNELS

“…Few authors (Arani and Amani ,2012;Kheram ,2011;Fakoor et al, 2013;Aliabadi et al, 2014;Youssef et al, 2012) have suggested the effect of geometry of the channel and nanoparticle size and concentration on the pressure drop across the channel. Vatani et al (2013) discussed the effect on heat transfer enhancement and friction factor for varying nanoparticle type, size and concentration for turbulent flow in triangular, square and arc shaped ribbed channel.…”

Numerical calculations of the thermal-aerodynamic characteristics in a solar duct with multiple V-baffles

“…in-line and staggered, by reducing the separation length between them. Vatani and Mohammed (2013) applied various rib-groove structures such as arc, square, and triangles with different nanofluids containing SiO 2 , ZnO, CuO, Al 2 O 3 to numerically investigate hydraulic and thermal characteristics of flow in the channel. As indicated in the results, the greatest Nusselt number can be achieved by using SiO 2 /water nanofluid among all the nanofluids.…”