Flow and heat transfer characteristics of the boundary layers over a stretching surface with a uniform-shear free stream

2008 ◽  
Vol 51 (9-10) ◽  
pp. 2199-2213 ◽  
Author(s):  
Tiegang Fang
1975 ◽  
Author(s):  
R. S. R. Gorla

Rotating blades provide some of the most challenging problems of fluid mechanics. The presence of secondary effects in the boundary layers over rotating blades results in the flow and heat transfer characteristics that are different from the classical two-dimensional boundary layer theory. In this paper, the unsteady velocity and thermal boundary layers have been solved for constant temperature boundary condition. By the use of small crossflow approximation, a perturbation analysis is developed to predict heat transfer characteristics. Numerical results for the universal functions proportional to primary flow and crossflow are presented. For the thermal problem, universal functions are presented for Pr = 0.70 and 1.0. Expressions for the skin friction coefficient as well as the Nusselt number have been derived.


Author(s):  
Mohammad M. Rahman ◽  
Mohammed M. Al-Hatmi

In this paper we investigate numerically the hydromagnetic boundary layer flow and heat transfer characteristics of a nanofluid using three types of nanoparticles (copper, aluminium oxide and titanium dioxide) having various shapes (spherical, cylindrical, arbitrary, etc) by considering three kinds of base fluids (water, ethylene glycol and engine oil) over a nonlinear inclined stretching surface, taking into account the effect of convective surface condition. Using similarity transformations, the governing nonlinear partial differential equations of the physical model are transformed into non-dimensional ordinary differential equations which are solved for local similar solutions using the very robust computer algebra software, Maple 13. The numerical simulation is carried out to investigate the role of the pertinent parameters on the flow and temperature fields as well as on the rate of heat transfer and on the rate of shear stress. The results show that the addition of nanoparticles to the base fluid may not always increase the rate of heat transfer. It depends significantly on the surface convection, type of base fluid and nanoparticles.  The finding of this study will open a gate for better understanding of nanofluid characteristics.  


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