Unsteady mixed convection on the stagnationpoint flow adjacent to a vertical plate with a magnetic field
 H. S. Takhar,
 A. J. Chamkha,
 G. Nath
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An analysis is performed to study the unsteady combined forced and free convection flow (mixed convection flow) of a viscous incompressible electrically conducting fluid in the vicinity of an axisymmetric stagnation point adjacent to a heated vertical surface. The unsteadiness in the flow and temperature fields is due to the free stream velocity, which varies arbitrarily with time. Both constant wall temperature and constant heat flux conditions are considered in this analysis. By using suitable transformations, the Navier–Stokes and energy equations with four independent variables (x, y, z, t) are reduced to a system of partial differential equations with two independent variables (η, τ). These transformations also uncouple the momentum and energy equations resulting in a primary axisymmetric flow, in an energy equation dependent on the primary flow and in a buoyancyinduced secondary flow dependent on both primary flow and energy. The resulting system of partial differential equations has been solved numerically by using both implicit finitedifference scheme and differentialdifference method. An interesting result is that for a decelerating free stream velocity, flow reversal occurs in the primary flow after certain instant of time and the magnetic field delays or prevents the flow reversal. The surface heat transfer and the surface shear stress in the primary flow increase with the magnetic field, but the surface shear stress in the buoyancyinduced secondary flow decreases. Further the heat transfer increases with the Prandtl number, but the surface shear stress in the secondary flow decreases.
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 Title
 Unsteady mixed convection on the stagnationpoint flow adjacent to a vertical plate with a magnetic field
 Journal

Heat and Mass Transfer
Volume 41, Issue 5 , pp 387398
 Cover Date
 20050301
 DOI
 10.1007/s0023100405371
 Print ISSN
 09477411
 Online ISSN
 14321181
 Publisher
 SpringerVerlag
 Additional Links
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 Authors

 H. S. Takhar ^{(1)}
 A. J. Chamkha ^{(2)}
 G. Nath ^{(3)}
 Author Affiliations

 1. Department of Engineering, Manchester Metropolitan University, Manchester, M1 5GD, UK
 2. Department of Mechanical Engineering, Kuwait University, P.O. Box 5969, Safat, 13060, Kuwait
 3. Department of Mathematics, Indian Institute of Science, Bangalore, 560012, India