[aspect-devel] Mass balance

[Wolfgang Bangerth]

On 06/21/2016 01:20 AM, Mohamed Gouiza wrote:
>
>
> I am runing a 2d model (box with x=500km; y=600km) with prescribed velocity
> (ve) on left and right boundaries (if y>=120km & x<250km, Ve=-1cm/year, if
> y>=120km & x>=250km, Ve=1cm/year).
>
> So I am loosing lithospheric material with time and I would like to replace it
> by astenospheric matrial. This is usually achieved by imposing a prescribed
> velocity (Vm) to the sublithospheric mantle bounderies (opposite to the one
> imposed to the lithospheric boundaries) to achieve masse balance with time. I
> can run Several simulations and try to find an empirical relationship between
> Ve and Vm, but I want to know if this can be done in more clever way?!

Mohamed -- why don't you just use no-stress boundary conditions at the bottom? 
This way, material will simply flow through the bottom as necessary to ensure 
mass conservation.

Best
  WB

-- 
------------------------------------------------------------------------
Wolfgang Bangerth               email:            bangerth at math.tamu.edu
                                 www: http://www.math.tamu.edu/~bangerth/