Non-Newtonian effect on natural convection flow over cylinder of elliptic cross section

doi:10.1007/s10483-020-2562-8

Abstract

Abstract: The non-Newtonian effect in the boundary layer flow over a horizontal elliptical cylinder is investigated numerically. A modified power-law viscosity model is used to correlate the non-Newtonian characteristics of the fluid flow. For natural convection flows, the surface of the cylinder is maintained by the uniform surface temperature (UST) or the uniform heat flux (UHF) condition. The governing equations corresponding to the flow are first transformed into a dimensionless non-similar form using suitable transformations. The resulting equations are solved numerically by an efficient finite difference scheme. The numerical results are presented for the skin friction coefficient and the local Nusselt number with the eccentric angle for different values of the power-law index n. The local skin friction coefficient and the local Nusselt number are found to be higher and lower, respectively, for the shear thickening fluids (n>1) than the other fluids (n ≤ 1). The effects of different elliptical configurations on the average Nusselt number are also presented and discussed for both conditions of the surface temperature.

Key words: non-Newtonian fluid, free convection, boundary layer, elliptical cylinder

2010 MSC Number:

P. NAG, M. M. MOLLA, M. A. HOSSAIN. Non-Newtonian effect on natural convection flow over cylinder of elliptic cross section. Applied Mathematics and Mechanics (English Edition), 2020, 41(2): 361-382.

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