[aspect-devel] velocity RMS

[Thieulot, dr. C. (Cedric)]

Hi,
I am trying to run a model where I impose on the right boundary an in/out-flux given by a cosine function. The integral of the flux on the boundary is therefore zero.
Here's what the input file looks like:

[...]
set Prescribed velocity boundary indicators = 1:function
[...]
subsection Boundary velocity model #velocity is prescribed on the right boundary to produce a balanced in- & outflow of material.
   subsection Function
      set Variable names      = x,z
      set Function constants  = a=100.0*3600.0*24.0*365.25 , pi=3.14159
      set Function expression = 5.0/a*cos(z/670000.*pi);0
   end
end

The amplitude of the cosine is 5cm/year. If you look at the attached images, you'll see that the velocity flow pattern I get and its magnitude are plausible/satisfactory.
However when I look at the statistics file I see that the RMS velocity (said to be in m/year) is around 6.5e5 and that the max velocity is around 1.6e6.
Correspondingly the timetsep dt is around 7e-4 years which stalls my simulation. I also attach the statistics file.
How is it this possible ?

cheers,

Cedric.




[cid:00fdc06e-dff8-4801-8b5c-1d6f063ad03b at uu.nl]


[cid:89ab3a09-fdb9-49cf-b6aa-4cc3c40ce2a5 at uu.nl]
[cid:90005681-a071-4078-926b-fcb29c59c5b7 at uu.nl]
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