A Generalized Approach to Influence Boundary Calculations in Computational Fluid Dynamics (CFD)

For many aerospace problems, experience has shown that geometric and/or physical model simplifications can be made with negligible influence on the overall accuracy of the solution. However, no general procedures for implementing influence boundary methods have been developed, and many calculations are still carried out in a rather ad-hoc basis. Thaerocomp Technical Corporation (TTC) is proposing to develop a generalized computational fluid dynamic (CFD)-based approach to influence boundary calculations. The proposed procedure will be developed into a software module that could be incorporated into government or third-party commercial CFD codes. The product will be the first of its kind; it will contain a robust and automatic procedure for identifying influence boundaries in realistic aerospace systems. The procedure will also automatically identify the appropriate boundary conditions in most influence boundary situations, and reconcile the CFD solution across influence boundaries that move at different speeds. An advantage of influence boundary procedures is the ability to solve the equations in each domain with a different tool that is appropriate for the physical model in the domain. TTC's procedure will allow the interchangeable use of different solvers in each influence domain, thereby accommodating third-party CFD tools.