Abstract
This study is devoted to investigating the importance of thermal radiation on the boundary layer over a horizontal surface considering classical constant surface boundary condition. The mathematical model consists of coupled two-dimensional partial differential equations which are transformed to the set of ordinary differential equations via the similarity transformation. The final set of dimensionless equations is solved numerically using Runge Kutta Fehlberg (RKF45) method in Maple software. The significant effect of the thermal radiation is examined using four fluids namely; water, Sulphur oxide, air and mercury whose respective Prandtl numbers are 7, 2, 0.72 and 0.044. The influence of other prominent parameters affecting the flow formation and temperature profile is demonstrated using tables and graphs. The results indicated that the thermal boundary layer thickness could be increase by reducing the Prandtl number. The results also showed that increasing the thermal radiation parameter has a positive impact on the boundary layer thickness. The heat transfer rate could be improved by increasing thermal radiation or decreased by increasing the values of the Prandtl number. Regarding the temperature gradient, an observable increasing is seen far from the flat plate with the growing of thermal radiation whereas the opposite trend is true near the plate surface.
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