BAAL: A code for calculating threedimensional fluid flows at all speeds with an EulerianLagrangian computing mesh
Abstract
A technique for computing the timedependent dynamics of threedimensional fluid flows is presented. The finite difference solution procedure is based upon an arbitrary LagrangianEulerian computing mesh whose vertices may move with the fluid (Lagrangian), remain fixed (Eulerian), or move in any prescribed manner. An implicit treatment of the pressure makes the method applicable to flows at all speeds, from far subsonic to far supersonic. The marker particles used may follow the motion of the fluid exactly to aid in flow visualization, or may represent particulate matter whose behavior is affected by inertia, drag, gravity, and diffusion. A derivation is included for generalized difference equations and their incorporation into a program called BAAL, for which portions of a FORTRAN listing are provided. Several sample calculations illustrate some of the uses and the flexibility of this new threedimensional computing technique.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 April 1976
 Bibcode:
 1976STIN...7721371P
 Keywords:

 Coding;
 EulerLagrange Equation;
 Three Dimensional Flow;
 Finite Difference Theory;
 Flow Visualization;
 Fortran;
 Time Dependence;
 Fluid Mechanics and Heat Transfer