The prediction of the drag on structural beams
Abstract
The usage of hodograph, wakesource, and vortex lattice theoretical potential flow models for characterizing the flow over bluff bodies is discussed. The models are employed to describe the drag of twodimensional bodies in terms of the wake and the irrotational components, which may feature a vortex street. The discussion is focused on calculations of the pressure distribution over the front face of I and Lbeam forms, which are important in the construction of buildings. The separation point occurs at the sharp edges, with a velocity that can be obtained by Bernoulli's equation. The hodograph method involves data on the velocity distribution at the boundaries, while the wakesource technique requires measurements of the position of the separation point on velocity. The vortexlattice method involves assumptions of zero velocity on the surface of the body, in addition to a set of control (separation) points, between which individual vortices are shed. The hodograph and wakesource methods are demonstrated to be useful only for shapes that are amenable to transformations.
 Publication:

Numerical Methods in Laminar and Turbulent Flow
 Pub Date:
 1981
 Bibcode:
 1981nmlt.proc..413G
 Keywords:

 Beams (Supports);
 Bluff Bodies;
 Drag;
 Flow Deflection;
 Potential Flow;
 Bernoulli Theorem;
 Computational Fluid Dynamics;
 Construction;
 Flow Velocity;
 Hodographs;
 I Beams;
 Pressure Distribution;
 Vortex Lattice Method;
 Vortex Shedding;
 Vortex Streets;
 Wakes;
 Fluid Mechanics and Heat Transfer