**ABSTRACT**

The present work aims at studying natural convection of nanofluids in a square enclosure embedded with a discrete heater at the bottom. The numerical simulations are performed using commercial software STAR CMM+ based on finite volume technique. Firstly, the results from the simulations are validated against the published results. Subsequently, numerical simulations have been carried out for predicting the flow and heat transfer characteristics of different water based nanofluids (Al2O3, Cu, TiO2) at wide range of Rayleigh numbers, volume fractions, position of the heater and heater length. Results are presented in the form of streamline plots, isotherm contours and plots of average Nusselt numbers. It has been found that the average Nusselt number increases with increasing Rayleigh number, volume fraction, and heater length. Further, the effect of heater position on the flow and temperature fields for different nanofluids are discussed. However, Nusselt number was observed to be sensitive to the position of the heater.

**KEYWORDS**

PAPER SUBMITTED: 2016-04-13

PAPER REVISED: 2016-11-28

PAPER ACCEPTED: 2016-12-23

PUBLISHED ONLINE: 2017-01-14

**THERMAL SCIENCE** YEAR

**2018**, VOLUME

**22**, ISSUE

**6**, PAGES [2771 - 2781]

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