NUMERICAL STUDY OF CONVECTIVE HEAT TRANSFER FOR A TURBULENT FLOW IN A CORRUGATED TUBE USING NANO FLUID

Abstract

Heat transfer enhancement can be done in different ways, but the use of nanofluid is one of the latest approaches. A numerical investigation of turbulent forced convection through a right-angled triangular-shaped corrugated tube is presented by using commercial computational fluid dynamics software, ANSYS Fluent. The length and diameter of the tube which is considered for the study are 200 mm and 8 mm respectively and a uniform constant heat flux of 5,000 W/m2 is applied at the corrugated wall boundary. A 2D simulation with the axisymmetric model is considered for analyzing different parameters. The corrugation has an amplitude of 1.60 mm and a wavelength of 6 mm. Realizable k-ε turbulent model is employed with enhanced wall treatment for the analysis. Nanofluid is allowed to flow with uniform velocity and uniform temperature of 300 K at the inlet of the pipe with an assumption of a no-slip condition. Heat transfer parameter like convective heat transfer coefficient and fluid dynamics parameter like friction factor and pumping power are calculated using three different nanofluids, namely Al2O3-water, TiO2-water, and CuO-water of different volume fraction (1%, 2%, 3%, 4% and 5%) for a range of Reynolds number 5000 to 25000. The result shows that the heat transfer coefficient increases with the increase in volume fraction of the nanofluid as well as with the Reynolds number. That is 44.66% for Al2O3-water, 27.35% for TiO2-water and 25.74% CuO-water nanofluid at Reynolds number of 25000 and 5% volume fraction.