A m a t l a b(r) version of CHIEF (Combined Helmholtz Integral Equation Formulation) for solving acoustic radiation and scattering problems

Abstract

The CHIEF program was developed during 1965–1988 at the Naval Ocean Systems Center. It was written in FORTRAN. The program uses the surface integral formulation of the Helmholtz equation to solve for acoustic pressure and velocity over a surface subject to surface geometry, boundary conditions, and incident field pressure on the surface. CHIEF uses a file interface to specify geometry, boundary conditions, etc., and writes its solutions for surface pressures to an output file. Thus, other programs are required for surface visualization and interpretation of results. Further, much of the original CHIEF FORTRAN code is devoted to bookkeeping imposed by machine limitations. As part of a larger modeling effort, CHIEF was ported to matlab. This makes the CHIEF methodology available as part of the matlab workbench approach to programming. Bookkeeping code that is no longer needed is discarded. Visualization tools are included as part of the new CHIEF environment. matlab functions are used where appropriate, combined with C++ code for speed when performing operations that are not vectorizable by matlab. The object-oriented features of matlab CHIEF are discussed as they apply to problem definition, visualization, and clarity and conciseness of programming. [Work supported by ONR 321 as Acoustic Measurement Methodology.]