## THERMAL SCIENCE

International Scientific Journal

### SIMULATION OF NATURAL CONVECTION HEAT TRANSFER USING NANOFLUID IN A CONCENTRIC ANNULUS

**ABSTRACT**

In the present study, natural convection of nanofluids in a concentric horizontal annulus enclosure has been numerically simulated using the lattice Boltzmann method. A water-based nanofluid containing Al2O3 nanoparticle has been studied. Simulations have been carried while the Rayleigh number ranges from 103 to 105 and solid volume fraction varies between 0 and 0.04. The effects of solid volume fraction of nanofluids on hydrodynamic and thermal characteristics such as average and local Nusselt numbers, streamlines, and isotherm patterns for different values of solid volume fraction, annulus gap width ratio and Rayleigh number are investigated and discussed in detail.

**KEYWORDS**

PAPER SUBMITTED: 2015-01-18

PAPER REVISED: 2015-04-23

PAPER ACCEPTED: 2015-05-02

PUBLISHED ONLINE: 2015-06-07

**THERMAL SCIENCE** YEAR

**2017**, VOLUME

**21**, ISSUE

**3**, PAGES [1275 - 1286]

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