[aspect-devel] velocity RMS

[Thieulot, dr. C. (Cedric)]

Hi Timo, 

thanks , we just figured it out too. However, in our input file we set it to true, 
and yet the statistics file outputs it in m/s (since as you just pointed out we have to divide the number by 3600x365x24) 

C.

 



On Dec 14, 2012, at 6:03 PM, Timo Heister wrote:

> Hi Cedric,
> 
> 5 cm/s are about 1.6e6 m/year, so I think something with the units
> does not add up correctly for you. Are you setting "set Use years in
> output instead of seconds = false"?
> 
> Oh, and what are the boundary conditions at the top and bottom? It
> looks like there are some artifacts on the top boundary...
> 
> On Fri, Dec 14, 2012 at 6:27 AM, Thieulot, dr. C. (Cedric)
> <c.thieulot at uu.nl> wrote:
>> 
>> 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.
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> _______________________________________________
>> Aspect-devel mailing list
>> Aspect-devel at geodynamics.org
>> http://geodynamics.org/cgi-bin/mailman/listinfo/aspect-devel
> 
> 
> 
> 
> --
> Timo Heister
> http://www.math.tamu.edu/~heister/
> _______________________________________________
> Aspect-devel mailing list
> Aspect-devel at geodynamics.org
> http://geodynamics.org/cgi-bin/mailman/listinfo/aspect-devel