On the mixed convection boundary-layer flow about a solid sphere with constant surface temperature

الملخص EN

The steady mixed convection boundary-layer flow of an incompressible viscous fluid about a solid sphere with constant surface temperature is considered for both aiding and opposing flow cases.

The transformed conservation equations of the no similar boundary-layers are solved numerically using a very efficient finite-difference method known as Keller-box scheme.

Numerical results are presented for different values of the mixed convection parameter λ with the Prandtl number Pr = 0.7 (air) and Pr = 6.8 (water at 21°C), respectively.

It is found that aiding flow (λ > 0) delays separation of the boundary-layer and can, if the aiding flow is strong enough, suppress it completely.

The opposing flow (λ < 0), on the other hand, brings the separation point nearer to the lower stagnation point of the sphere and for sufficiently strong opposing flows there will not be a boundary-layer on the sphere.

Some results were given in the form of tables.

Such tables are very important and they can serve as a reference against which other exact or approximate solutions can be compared in the future.