Application of a LogLinear Element to a FiniteElement BoundaryLayer Flow Model
Abstract
The finite element method was used to develop a class of boundary elements for the modeling of geophysical flows. These elements have both logarithmic and linear terms for the vertical direction and a quadratic function in the streamwise direction to permit a more accurate representation of the logarithmic velocity profile normal to the boundary. The loglinear element was tested against a conventional (9node) element in a onedimensional timedependent simulation of diffusiondominated flow of 50 m depth over a surface of assumed roughness. The result of the single loglinear element and results from the conventional method using two grids of 6 and 10 quadratic elements were compared with the analytic solution. The present element demonstrates superior accuracy. Nearly identical results were obtained in onedimensional highresolution simulations of neutral flow in the lowest 1500 m with and without the loglinear boundary element. The influence on the flow produced by cooling at the earth's surface is also studied.
 Publication:

Journal of Computational Physics
 Pub Date:
 March 1984
 DOI:
 10.1016/00219991(84)900743
 Bibcode:
 1984JCoPh..53..513T
 Keywords:

 Atmospheric Models;
 Boundary Layer Flow;
 Computational Fluid Dynamics;
 Finite Element Method;
 Geophysical Fluids;
 Atmospheric Circulation;
 Planetary Boundary Layer;
 Temperature Distribution;
 Time Marching;
 Velocity Distribution;
 Fluid Mechanics and Heat Transfer