Two Approaches to the Three-Dimensional Jet-In-Cross Wind Problem: A Vortex Lattice Model and a Numerical Solution of the Navier-Stokes Equations

摘要

A three-dimensional numerical solution of the time-dependent, incompressible Navier-Stokes equations based on an integro-differential formulation of these equations is developed. With this formulation it is possible to obtain the complete solution in the entire flow field while restricting the actual computational field to the region of significant vorticity magnitude of each time. This allows a considerable reduction in the computer storage required, since only the field points having significant vorticity at any time need be stored at that time, and calculations are actually performed only at those points at that time. The validity of the numerical solution is established by comparison of the results with the exact solution for the time-dependent, one-dimensional flow over a suddenly accelerated infinite flat plate moving parallel to itself at constant velocity, and by comparison of surface pressure and drag coefficients with experimental results, and with the results of other numerical solutions for the two-dimensional flow about a circular cylinder. The numerical solution is applied to the flow field of an infinite jet in a cross-flow and to the flow field of a jet issuing perpendicularly from an infinite plane wall into a cross-flow parallel to the wall. (Author)