[CIG-SHORT] on the viscosity coefficient

[Charles Williams]

Dear Yuta Abe,

I will look at the code and the manual to see if there is a problem.  As I mentioned in a previous e-mail to cig-short, we are changing the input parameters for power-law materials, so 'eta' will no longer be a parameter in upcoming versions.  I will let you know what I find out about version 1.4.2, though.

I'm glad the final output matches the analytical solution.  Would it be possible for you to describe the problem?  It may be useful as an example problem or benchmark.

Cheers,
Charles

On 4/03/2010, at 9:07 PM, Yuta Abe wrote:

> Dear PyLith Developers:
> 
>  I have a question about the viscosity_coefficient "eta", which is one of the physical properties that you get in the output "cel_info_fields" when you carry out analysis of a power-law viscoelastic material using PyLith 1.4.2.
> 
>  I thought the values of "eta" could be calculated using the equations (5.74), (5.75) and (5.76) by substituting the power-law coefficient "At" and the power-law exponent n. I substituted "At"=1.99e-41 and n=3 into those equations, and obtained "eta"=1.77e+13 as a result. However, the value of "eta" in info.vtk file which was obtained as an automatic output of the PyLith program for the same values of "At"=1.99e-41 and n=3 was "eta"=1.77e+18, 100,000 times as large as the above value. By the way, the final output of the PyLith program coincided with the analytical solution.
> 
> I would like to find out the origin of this difference, so please kindly tell me how the value of "eta" is calculated within the PyLith program.
> 
> 
> ------------------------------------------------------
> Yuta ABE
> Active Fault and Earthquake Reserch Center
> National Institute of Advanced Industrial Science and Technology,Japan
> tel; +81-29-861-3686
> email; yuta-abe at aist.go.jp
> -------------------------------------------------------  
> _______________________________________________
> CIG-SHORT mailing list
> CIG-SHORT at geodynamics.org
> http://geodynamics.org/cgi-bin/mailman/listinfo/cig-short

Charles A. Williams
Scientist
GNS Science
1 Fairway Drive, Avalon
PO Box 30368
Lower Hutt  5040
New Zealand
ph (office): 0064-4570-4566
fax (office): 0064-4570-4600
C.Williams at gns.cri.nz
NOTE NEW E-MAIL ADDRESS

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://geodynamics.org/pipermail/cig-short/attachments/20100305/dbaf0bdf/attachment.htm