[aspect-devel] Using of multicomponent

Wed Jun 15 10:14:56 PDT 2016

Hi Liu,

Indeed, does not look like subduction or plate like behavior in general.  It’s hard to tell what exactly is happening (and why) just from the screen shots you sent.  

For every snapshot you showed, can you send an image of the density?  Can you also send the .prm file and compositional data file you ran the code with (i.e. not in a word document)?  

In the initial stages of the model run, do you have a sense of what is the dominant force driving deformation (boundary conditions, internal density variations, etc)?

Last, is your setup based on a specific previous study?  A good place to start might be to reproduce the subduction benchmark of Schmeling et al. 2008 (PEPI, vol 171, pages 198-223, “A benchmark comparison of spontaneous subduction models - Towards a free surface" ).  Figure 1 in that paper has a detailed description of the setup.  

Cheers,
John

*************************************************
Assistant Project Scientist, CIG
Earth & Planetary Sciences Dept., UC Davis

> On Jun 14, 2016, at 9:45 PM, Liumengxue <liumengxue14 at mails.ucas.ac.cn> wrote:
> 
> Hi，
> This is the code in my .prm file:
> --------------------------------------------------------
> 
> # 4 Compositional fields,
> 
> # read from ***.txt
> 
> 
> set Dimension = 2
> 
> set CFL number = 0.5
> 
> set End time = 1.e6 # 1Ma,100steps
> 
> set Output directory = /home/lmx/candi/Tdata/test-C4
> 
> set Pressure normalization = no
> 
> set Use years in output instead of seconds = true
> 
> 
> 
> 
> subsection Geometry model
> 
>     set Model name = box
> 
>     subsection Box
> 
>         set X extent = 1000.e3 # 500km*200km
> 
>         set Y extent = 700.e3
> 
>          set X repetitions = 5
> 
>          set Y repetitions = 2
> 
>     end
> 
> end
> 
> 
> #------------------convection-2d------------------------
> 
> #subsection Boundary temperature model
> 
> # set Model name = constant
> 
> # subsection Constant
> 
> # set Boundary indicator to temperature mappings = left:0, right:0, bottom:0, top:0
> 
> # end
> 
> #end
> 
> #
> 
> subsection Boundary temperature model
> 
>    set Model name = box
> 
> 
>    subsection Box
> 
>         set Bottom temperature = 1974.
> 
>         set Left temperature = 0
> 
>         set Right temperature = 0
> 
>         set Top temperature = 274. # 0 centigrade
> 
>     end
> 
> end
> 
> #----------------------------
> 
> subsection Initial conditions
> 
>    set Model name = function
> 
> 
>    subsection Function
> 
>       set Variable names = x,z
> 
>       set Function constants = p=0.01, L=1, pi=3.1415926536, k=1
> 
>       set Function expression = (1974.-z) - p*cos(k*pi*x/L)*sin(pi*z)
> 
>    end
> 
> end
> 
> #-------------------------------------------------------------------------
> 
> 
> 
> subsection Discretization
> 
>     set Use locally conservative discretization = false
> 
>     subsection Stabilization parameters
> 
>        set alpha = 2
> 
>        set beta = 0.078
> 
>         set cR = 0.5
> 
>     end
> 
> end
> 
> 
> 
> subsection Gravity model
> 
> set Model name = vertical
> 
> subsection Vertical
> 
> set Magnitude = 9.8
> 
> end
> 
> end
> 
> 
> 
> subsection Mesh refinement
> 
> set Additional refinement times =
> 
> set Initial adaptive refinement = 0
> 
> set Initial global refinement = 5
> 
> set Refinement fraction = 0.3
> 
> set Coarsening fraction = 0.05
> 
> set Strategy = temperature
> 
> set Time steps between mesh refinement = 10
> 
> end
> 
> 
> 
> subsection Model settings
> 
> set Include adiabatic heating = false
> 
> set Include shear heating = false
> 
> set Fixed temperature boundary indicators = 0,1,2,3
> 
> set Prescribed velocity boundary indicators =
> 
> set Tangential velocity boundary indicators = 2,3
> 
> set Zero velocity boundary indicators = 0,1
> 
> 
> # set Free surface boundary indicators = 3 # free surface:top
> 
> end
> 
> 
> #-----------boundary velocity condition
> 
> subsection Boundary velocity model
> 
> subsection Function
> 
> set Variable names = x,z
> 
> # set Function constants = cm=0.01, year=1 # crustal_model_2D
> 
> # set Function expression = if (x<40e3 , 1*cm/year, -1*cm/year) ; 0
> 
> set Function expression = if (z >600.e3 && z<670.e3 && x <= 330.e3 ,5.e-2, 0);0 # x and z components,
> 
> end
> 
> end
> 
> 
> #subsection Free surface
> 
> # set Free surface stabilization theta = 0.5
> 
> #end
> 
> 
> subsection Postprocess
> 
> set List of postprocessors = visualization,topography,velocity statistics
> 
> 
> subsection Visualization
> 
> set List of output variables = viscosity,stress,density
> 
> set Time between graphical output = 1.e4
> 
> end
> 
> end
> 
> 
> # 改动1
> 
> # 加入3个组分场,subduct plate,overide plate and a small interplate weak zone；
> 
> subsection Compositional fields
> 
> set Number of fields = 4 #
> 
> end
> 
> 
> subsection Compositional initial conditions
> 
> set Model name = ascii data
> 
> 
> subsection Ascii data model
> 
> set Data directory = /home/lmx/candi/aspect/myapp/ #use absolute directory
> 
> set Data file name = c4data.txt
> 
> end
> 
> end
> 
> 
> # Another Material model 改动2,
> 
> # need subcection Compositional fields to difine different compositional fields,
> 
> # then give material parameters of compositional fields,respectively
> 
> subsection Material model
> 
> set Model name = multicomponent
> 
> set Material averaging = harmonic average
> 
> subsection Multicomponent
> 
> set Densities = 3300,1,2900,2900,2900
> 
> set Specific heats = 1250
> 
> set Reference temperature = 0.0
> 
> set Thermal conductivities = 4.0
> 
> set Thermal expansivities = 3e-5
> 
> set Viscosities = 1.e20,1.e18,1.e23,1e20,1e23
> 
> end
> 
> end 
> 
> 
> 
> --------------------------------------------------------------------------------------------------------
> 
> Last email I've already attached my prm file and data file of compositional fields,here I give 3 screenshoots of my results in the attachment,if you can't see that,please let me konw.Then if it's ok for you to give me an email address,I'll send them to you later.Thanks !
> 
> 
> 
> Cheers,
> 
> Liu
> 
> 
> 
> 
> 
> <time0.png><time1.png><time100.png>_______________________________________________
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