Mixed convection in turbulent boundary layer flow over a horizontal plate
Abstract
An analytical investigation of turbulent mixed convection over an isothermal horizontal flat plate is undertaken. The effect of buoyancy force on the eddy diffusivities for momentum and heat is accounted for through the use of an extended version of the Van Driest mixing length model. The governing system of equations is transformed into a dimensionless form, and then solved by a finite difference scheme. Numerical results are presented for a Prandtl number of 0.7, and cover the range of the buoyancy force parameter from 0 to 1,000 for assisting flow, with local Reynolds numbers lower than 10 million and local Grashof numbers lower than 10 to the 15th power. It has been found that both the local wall shear stress and the local surface heat flux increase with increasing buoyancy force intensity. It has also been demonstrated that turbulent mixed convection over a horizontal plate provides substantially lower surface heat transfer rates than pure natural convection when the buoyancy force parameter is greater than 0.001. The present analytical predictions are in qualitative agreement with limited available experimental data.
- Publication:
-
American Society of Mechanical Engineers
- Pub Date:
- November 1983
- Bibcode:
- 1983asme.meetQ....A
- Keywords:
-
- Boundary Layer Flow;
- Computational Fluid Dynamics;
- Free Convection;
- Turbulent Boundary Layer;
- Turbulent Mixing;
- Wall Flow;
- Finite Difference Theory;
- Flat Plates;
- Isothermal Flow;
- Mixing Length Flow Theory;
- Fluid Mechanics and Heat Transfer