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ESCI SJR: 0.249 SNIP: 0.434 CiteScore™: 0.7

ISSN Imprimir: 1940-2503
ISSN En Línea: 1940-2554

# Computational Thermal Sciences: An International Journal

DOI: 10.1615/ComputThermalScien.2017019049
pages 227-241

## HEAT TRANSFER ENHANCEMENT OF UNIFORMLY/LINEARLY HEATED SIDE WALL IN A SQUARE ENCLOSURE UTILIZING ALUMINA−WATER NANOFLUID

Saritha Natesan
School of Mechanical Engineering, VIT University, Vellore, India
Senthil Kumar Arumugam
School of Mechanical Engineering, VIT University, Vellore, India
Sathiyamoorthy Murugesan
Department of Mathematics, Government Thirumagal Mills College, Gudiyatham, Vellore, India
Ali J. Chamkha
Department of Mechanical Engineering, Prince Sultan Endowment for Energy and Environment, Prince Mohammad Bin Fahd University, Al-Khobar 31952, Kingdom of Saudi Arabia; RAK Research and Innovation Center, American University of Ras Al Khaimah, United Arab Emirates, 10021

### SINOPSIS

A numerical study is carried out on natural convection flow of Al2O3-water nanofluid in a square cavity when the left wall is uniformly (or) linearly heated and the right wall is cooled whereas the top and bottom walls are well insulated. A computational code is developed based on the SIMPLE algorithm, and the finite volume method is used to solve the discretized equations. The Maxwell-Garnett and the Brinkman models are used to evaluate the nanofluid thermal conductivity and dynamic viscosity, respectively. Numerical results are presented in terms of the velocity profiles, stream functions, and isotherm contours, and the local and average Nusselt numbers for a wide range of the Rayleigh number Ra = 104 − 106 and the solid volume fraction (0 ≤ φ ≤ 0.2) at the Prandtl number Pr = 6.2. It is found that, for both cases of boundary conditions, the average Nusselt number increases as the volume fraction increases at a given Rayleigh number. That is, the heat transfer rate performance is improved by the addition of alumina nanoparticles in water. However, the overall heat transfer rate at the left wall for the linearly heated case is less than that for the uniformly heated case with the corresponding values of Ra and φ.