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solvers:ssa [Elmer/Ice Wiki]

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solvers:ssa [2013/12/10 16:57]
gag [General Description]
solvers:ssa [2017/05/19 05:20] (current)
tzwinger [General Description]
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 ==== General Informations ==== ==== General Informations ====
-:!: **Important changes have been made in ''SSABasalSolver''. This doc applies from Rev. 6472.**+:!: **Important changes have been made in ''SSABasalSolver''. This doc applies from Rev. 6480.**
  
   * **Solver Fortran File:** ''SSASolver.f90''   * **Solver Fortran File:** ''SSASolver.f90''
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 The ''Mean Density'' and ''Mean Viscosity'', if not uniform along the vertical direction, can be computed using the ''GetMeanValueSolver'' routine or the ''StucturedProjectToPlan'' solver (preferred solution). The ''Mean Density'' and ''Mean Viscosity'', if not uniform along the vertical direction, can be computed using the ''GetMeanValueSolver'' routine or the ''StucturedProjectToPlan'' solver (preferred solution).
  
-Contrary to the NS solver, the gravity must be orientated along the z-axis and it taken form the value of+Contrary to the NS solver, the gravity must be orientated along the z-axis and is taken from the value of
 ''Flow BodyForce 2'' for a SSA-1D problem or ''Flow BodyForce 3'' for a SSA-2D problem. ''Flow BodyForce 2'' for a SSA-1D problem or ''Flow BodyForce 3'' for a SSA-2D problem.
  
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 Note that in the absence of explicit boundary condition (no dirichlet condition or ''Calving front = Logical True'' not found) the natural boundary condition is force equilibrium (//rho_ice * h^2 = rho_water * h_im^2//). Note that in the absence of explicit boundary condition (no dirichlet condition or ''Calving front = Logical True'' not found) the natural boundary condition is force equilibrium (//rho_ice * h^2 = rho_water * h_im^2//).
  
-The SSA velocities and pressure can be use, for example, as initial conditions for the Stokes Solver. +The SSA velocities and pressure can be used, for example, as initial conditions for the Stokes Solver. 
  
  
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 === Basal friction === === Basal friction ===
  
-Since version 6472, there are three friction laws implemented in the SSA solver: +Since version 6480, there are three friction laws implemented in the SSA solver: 
  
   * a linear friction law   * a linear friction law
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     * ''SSA Friction Maximum Value'' -> <m>C</m> ~ max bed slope     * ''SSA Friction Maximum Value'' -> <m>C</m> ~ max bed slope
     * ''Effective Pressure'' (variable) -> <m>N</m>     * ''Effective Pressure'' (variable) -> <m>N</m>
 +    * '' SSA Min Effective Pressure'' -> <m>N_{min}</m>, such that <m>N >= N_{min}</m>
  
 When  <m>u_b = (u^2+v^2)^{1/2}< u_{t0}</m>, <m>u_b</m> in the previous equations is replaced by <m>u_{t0}</m>. When  <m>u_b = (u^2+v^2)^{1/2}< u_{t0}</m>, <m>u_b</m> in the previous equations is replaced by <m>u_{t0}</m>.
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 ==== Examples ==== ==== Examples ====
-For examples look in your elmer source distribution under ''[ELMER_TRUNK]/elmerice/examples/Test_SSA''.+For examples look in your elmer source distribution under ''[ELMER_TRUNK]/elmerice/Tests/SSA'' and under ''[ELMER_TRUNK]/elmerice/examples/Test_SSA''.
solvers/ssa.1386694662.txt.gz ยท Last modified: 2013/12/10 16:57 by gag
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