Axisymmetric Flows in the Boundary Layer of a Maintained Vortex

View More View Less
  • 1 Dept. of the Geophysical Sciences, The University of Chicago
© Get Permissions
Full access

Abstract

The three-dimensional flow in the boundary layer of a tornado-like vortex, with a core region of large vorticity and an outer region of nearly zero vorticity, is obtained by alternatingly solving the two nonlinear boundary-layer equations for the radial and the vertical distributions of the velocities. It is found that in the inner region the flow is of the Ekman-layer type, with an oscillatory distribution of the velocities in the vertical, while in the outer region the flow is of the ordinary boundary-layer type, with the velocity components approaching their respective values asymptotically without oscillation at a large distance from the boundary. This distribution of the radial velocity results in a weak descending motion in the outer region and a relatively strong ascending motion in the inner region with a sharp maximum upward motion occurring inside the radius of the maximum tangential wind where the boundary-layer thickness increases most rapidly outward.

Abstract

The three-dimensional flow in the boundary layer of a tornado-like vortex, with a core region of large vorticity and an outer region of nearly zero vorticity, is obtained by alternatingly solving the two nonlinear boundary-layer equations for the radial and the vertical distributions of the velocities. It is found that in the inner region the flow is of the Ekman-layer type, with an oscillatory distribution of the velocities in the vertical, while in the outer region the flow is of the ordinary boundary-layer type, with the velocity components approaching their respective values asymptotically without oscillation at a large distance from the boundary. This distribution of the radial velocity results in a weak descending motion in the outer region and a relatively strong ascending motion in the inner region with a sharp maximum upward motion occurring inside the radius of the maximum tangential wind where the boundary-layer thickness increases most rapidly outward.

Save