[cig-commits] r21640 - seismo/3D/SPECFEM3D/trunk/examples/CPML/purely_elastic

[dkomati1 at geodynamics.org]

Author: dkomati1
Date: 2013-03-26 07:51:01 -0700 (Tue, 26 Mar 2013)
New Revision: 21640

Added:
   seismo/3D/SPECFEM3D/trunk/examples/CPML/purely_elastic/geometrical_properties_of_this_PML_mesh.txt
Log:
added examples/CPML/purely_elastic/geometrical_properties_of_this_PML_mesh.txt


Added: seismo/3D/SPECFEM3D/trunk/examples/CPML/purely_elastic/geometrical_properties_of_this_PML_mesh.txt
===================================================================
--- seismo/3D/SPECFEM3D/trunk/examples/CPML/purely_elastic/geometrical_properties_of_this_PML_mesh.txt	                        (rev 0)
+++ seismo/3D/SPECFEM3D/trunk/examples/CPML/purely_elastic/geometrical_properties_of_this_PML_mesh.txt	2013-03-26 14:51:01 UTC (rev 21640)
@@ -0,0 +1,29 @@
+
+- regular mesh
+
+- flat model edges aligned with the coordinate axes X, Y and Z
+
+- 12 spectral elements along X, 12 spectral elements along X, 13 spectral elements along Z
+
+- thus total number of spectral elements = 12 * 12 * 13 = 1872
+
+- size of the model:
+
+ X min max =    273500.0 m     352100.0 m    deltaX = 78600.00 m (size of the whole model)
+ Y min max =    3614900. m     3691600. m    deltaY = 76700.00 m (size of the whole model)
+ Z min max =   -79785.46 m    -685.4575 m    deltaZ = 79100.00 m (size of the whole model)
+
+- size of a spectral element:
+
+ X size = 78600.00 / 12 = 6550 m
+ Y size = 76700.00 / 12 = 6391.67 m
+ Z size = 79100.00 / 13 = 6084.615 m
+
+- elastic material of constant properties in the whole mesh:  rho =  2300 kg/m3, Vp = 2800 m/s, Vs = 1500 m/s,   no viscoelasticity (no attenuation); Vp / Vs ratio = 2800 / 1500 = 1.86667
+
+- using 5 grid points per minimum wavelength to get an accurate simulation, i.e. one spectral element per minimum wavelength (since NGLL = 5 in each spectral element), this means that the shortest S wavelength in the model should be 6550 m;  since lambda_S_min = Vs / frequency_max, this means that we should use:
+
+frequency_max = Vs / lambda_S_min = 1500 / 6550 = 0.229 Hz
+
+- since for a Ricker source the dominant frequency f0 is approximately frequency_max / 2.5, this means that for the source we should select a f0 equal to 0.229 / 2.5 = 0.09160 Hz (and use it also for f0_FOR_PML in the Par_file then)
+