Accession Number : ADA191441

Title :   Transmitting Boundary for Finite-Difference Calculations with Finite Modeling of An Infinite Medium.

Descriptive Note : Final rept. 1 Dec 84-30 Apr 86,

Corporate Author : SCIENCE APPLICATIONS INTERNATIONAL CORP SAN FRANCISCO CA

Personal Author(s) : Yeung, William ; Gross, Michael B

PDF Url : ADA191441

Report Date : 20 Nov 1987

Pagination or Media Count : 50

Abstract : The purpose of this effort was to study the construction of novel energy absorbing boundary conditions for use at the artificial far field boundaries of exterior wave problems. One approach was pursued which involves the superposition of the solutions for a fixed boundary and for a free boundary. An analytic model was used to identify the cause of the small errors that result in the cancellation process of this approach. This model showed that the appropriate velocity at the free boundary has to be modified when the computational time step is less than the maximum stable time step. First and second order corrections have been developed.

Descriptors :   *ENERGY ABSORBERS, *FINITE DIFFERENCE THEORY, *MATHEMATICAL MODELS, *ACOUSTIC WAVES, *NOISE REDUCTION, BOUNDARIES, CANCELLATION, COMPUTATIONS, CORRECTIONS, ERRORS, EXTERNAL, FAR FIELD, STABILITY, TIME, TRANSMITTING, ACOUSTIC REFLECTION, TRANSITIONS

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE