## THERMAL SCIENCE

International Scientific Journal

### Thermal Science - Online First

online first only
### Impact of surface texture on natural convection boundary layer of nanofluid

**ABSTRACT**

Heat transfer characteristics are investigated in natural convection flow of water-based nanofluid near a vertical rough wall. The analysis considers five different nanoparticles, namely, silver (Ag), copper (Cu), alumina (Al2O3), magnetite (Fe3O4)and silica (SiO2). The concentration has been limited between 0-20% for all types of nanoparticle. The governing equations are modeled using the Boussinesq approximation and Tiwari and Das model is utilized to represent the nanofluid. The analysis examines the effects of the nanoparticle volume fraction, the type of nanofluid and the wavy surface geometry parameter on the skin friction and Nusselt number. It is observed that for a given nanofluid the skin friction and Nusselt number can be maximized via an appropriate tuning of the wavy surface geometry parameter along with the selection of suitable nanoparticle. Particular to this study copper (Cu) is observed to be more productive towards the flow and heat transfer enhancement. In total the metallic oxides are found to be less beneficial as compared to the pure metals.

**KEYWORDS**

PAPER SUBMITTED: 2015-10-08

PAPER REVISED: 2016-04-08

PAPER ACCEPTED: 2016-05-17

PUBLISHED ONLINE: 2016-05-30

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