At Raytheon BBN Technologies we developed a numerical propagation model for broadband acoustic sources through realistic atmospheres. The first phase of this project focused on a thorough investigation of a numerical propagation strategy within a relatively simple domain and environmental characterizations, e.g., linearization. Our algorithm utilized Fourier spectral methods for spatial operators and a fourth-order Runge-Kutta technique, modified by the method of integrating factors [9], for the time integration. Our model was able to capture the influence of horizontal winds in a variable sound speed environment. Subsequent efforts of this project include the implementation of polynomial-based spectral methods on a multi-domain grid. This would allow for greater resolution where needed, implementation of mixed boundary conditions, and parallelization for computational efficiency. We would also like to introduce additional realism into the existing structure, including 3-D, variable density and nonlinear terms.

Subsequent efforts of this project include the implementation of polynomial-based spectral methods on a multi-domain grid. This would allow for greater resolution where needed, implementation of mixed boundary conditions, and parallelization for computational efficiency. We would also like to introduce additional realism into the existing structure, including 3-D, variable density and nonlinear terms.

K. Bongiovanni, K. Chowdhary, and M. Soyka. Infrasound Broadband Pulse Propagation in a Moving Inhomogeneous Medium. Raytheon BBN Technologies Technical Report, 2010. pdf

K. Chowdhary. Notes on one-dimensional multi-domain spectral penalty methods. pdf