scholarly journals Staggered-grid finite-difference acoustic modeling with the Time-Domain Atmospheric Acoustic Propagation Suite (TDAAPS).

2005 ◽  
Author(s):  
David Franklin Aldridge ◽  
Sandra L. Collier ◽  
David H. Marlin ◽  
Vladimir E. Ostashev ◽  
Neill Phillip Symons ◽  
...  
Geophysics ◽  
1994 ◽  
Vol 59 (2) ◽  
pp. 290-296 ◽  
Author(s):  
E. S. Krebes ◽  
Gerardo Quiroga‐Goode

We show that the finite‐differencing technique based on the consecutive application of the central difference operator to spatial derivatives, a standard well‐known technique that has been commonly used in the seismological literature for solving the elastic equation of motion, can also be used to obtain a stable time‐domain, finite‐difference scheme for solving the anelastic equation of motion. We compare the results of the scheme for a heterogeneous medium with those of the time‐domain finite‐difference scheme previously developed by Emmerich and Korn and find that they agree very closely. We show, analytically, that in the case of a homogeneous medium, the two schemes give identical numerical results for certain zero initial conditions. The scheme based on the standard technique uses more computer time and memory than the scheme of Emmerich and Korn. However, from a theoretical viewpoint, it is easier to analyze, as it is developed solely with a familiar standard method.


Author(s):  
Z. Charlie Zheng ◽  
Guoyi Ke

Conventional time-domain schemes have limited capability in modeling long-range acoustic propagation because of the vast computer resources needed to cover the entire region of interest with a computational domain. Many of the long-range acoustic propagation problems need to consider propagation distances of hundreds or thousands of meters. It is thus very difficult to maintain adequate grid resolution for such a large computational domain, even with the state-of-the-art capacity in computer memory and computing speed. In order to overcome this barrier, a moving zonal-domain approach is developed. This concept uses a moving computational domain that follows an acoustic wave. The size and interval of motion of the domain are problem dependent. In this paper, an Euler-type moving domain in a stationary coordinate frame is first tested. Size effects and boundary conditions for the moving domain are considered. The results are compared and verified with both analytical solutions and results from the non-zonal domain. Issues of using the moving zonal-domain with perfectly-matched layers for the free-space boundary are also discussed.


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