Modeling Nonlinear Acoustical Blast Waves Outdoors: A Research Summary
Abstract
Current techniques for predicting sound propagation outdoors do not accurately model the physics of very loud sounds (over 150 dB), where the mathematics governing the sound propagation become nonlinear. As a result, Army installations need to measure and characterize impulse noises from actual blasts to anticipate environmental impacts of military operations on neighboring communities. This report summarizes research that developed and verified a numerical method to model nonlinear acoustical blast waves, and investigated the interaction between the finite amplitude blast waves and a natural ground surface. Absorbing boundary conditions were also developed to allow for a numerical solution on a relatively small computational domain. It was determined that, as the finite amplitude effects are increased, the effect of a finite ground impedance is decreased. Since this relationship is itself nonlinear, this implies that the practice of simply adding finite amplitude effects and ground surface effects to find sound levels is not valid. Linear extrapolations and techniques should only be used where linear acoustics are applicable.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1991
- Accession Number
- ADA241030
Entities
People
- Victor W. Sparrow
Organizations
- Construction Engineering Research Laboratory