TRANSIENT LAMINAR NATURAL-CONVECTION FROM HORIZONTAL CYLINDERS

The unsteady laminar natural convection flow from a heated horizontal cylinder under diverse surface boundary conditions is investigated numerically using the spline fractional step method. Some characteristics of the boundary layer obtained with a scale analysis are compared with the numerical results. The development of the plume region as well as the surface heat transfer and local flow field are evaluated. At small times, the present numerical solutions approach the boundary layer results and are in good agreement with the results from the scale analysis. A more detailed study of the development of the plume region, using computed particle trajectories is reported. All results are obtained using a personal computer. Qualitative comparisons between the present results and flow visualization experiments partially verify the numerical results.