Mixed convection boundary layer on a solid sphere with constant surface heat flux
The steady mixed convection boundary layer flow of an incompressible viscous fluid on a solid sphere with a constant surface heat flux qw is considered for both the assisting and the opposing flow cases. The transformed governing equations of the non-similar boundary layers are solved numerically...
Main Authors: | , |
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Format: | Article |
Published: |
Penerbit ukm
2006
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Online Access: | http://journalarticle.ukm.my/1821/ http://journalarticle.ukm.my/1821/ |
Summary: | The steady mixed convection boundary layer flow of an incompressible viscous fluid on a
solid sphere with a constant surface heat flux qw is considered for both the assisting and the
opposing flow cases. The transformed governing equations of the non-similar boundary layers
are solved numerically using the Keller-box method. Numerical results are presented for
different values of the mixed convection parameter λ and for the Prandtl number, Pr = 0.7
(air) and Pr = 7 (water). The numerical results obtained include local skin friction coefficient
Cf, local wall temperature distribution θw (x) , velocity and temperature profiles. It is found
that the assisting flow (λ > 0) delays the separation of the boundary layers, and if the
assisting flow is strong enough, it suppresses the separation completely. On the other hand, the
opposing flow (λ < 0) brings the separation point nearer to the lower stagnation point ( x ≈ 0 )
of the sphere, and for sufficiently strong opposing flows, there will not be a boundary layer on
the sphere |
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