Merge pull request #6129 from danieldouglas92/fix_units_in_darcy_velo…

…city_viz

Fix the units for the darcy velocity postprocessor

source/postprocess/visualization/darcy_velocity.cc

@@ -87,9 +87,9 @@ namespace aspect
             const double fluid_density = fluid_out->fluid_densities[q];
             const double permeability = fluid_out->permeabilities[q];
             const Tensor<1,dim> solid_velocity = in.velocity[q];
-            const Tensor<1,dim> darcy_velocity = solid_velocity -
-                                                 permeability / fluid_viscosity / porosity * gravity *
-                                                 (solid_density - fluid_density) * velocity_scaling_factor;
+            const Tensor<1,dim> darcy_velocity = (solid_velocity -
+                                                  permeability / fluid_viscosity / porosity * gravity *
+                                                  (solid_density - fluid_density)) * velocity_scaling_factor;
 
             for (unsigned int k=0; k<dim; ++k)
               computed_quantities[q](k) = darcy_velocity[k];

tests/darcy_convection_step.prm

@@ -8,7 +8,7 @@
 # u_f = u_s - K_D / phi * (rho_s * g - rho_f * g)
 # u_f = fluid velocity # m/yr
 # u_s = solid velocity # m/yr
-# K_D = Darcy Coefficient = k / eta_f
+# K_D = Darcy Coefficient # m3 s / kg
 # k = permeability # m2 / s
 # eta_f = fluid viscosity # Pa s
 # phi = porosity
@@ -23,12 +23,14 @@
 # Where k_0 is the reference permeability. The test is a 10 km x 10 km 2D
 # box with a uniform porosity of 0.02 (2%) everywhere. The fluid has a
 # density of 1000 kg/m3, and a viscosity of 10 Pa s, and the solid has a
-# density of 3000 kg/m3 and a uniform velocity of 0 m/yr. The reference
-# pemeability is 1e-6, and gravity is set to -10. This results in a fluid
-# velocity of 24.25 m/yr. The mesh is 2.5 km x 2.5 km, and with CFL = 1,
-# this means that the time step should be 2500 m / 24.25 m/yr = 103.11
+# density of 3000 kg/m3 with an x velocity of 0.001 m/yr and a y velocity of
+# 0.75 m/yr. The reference pemeability is 1e-6, and gravity is set to -10.
+# This results in a fluid velocity of ~24.9958 m/yr in the y direction, and
+# 0.001 m/yr in the x direction The mesh is 2.5 km x 2.5 km, and with CFL = 1,
+# this means that the first time step should be 2500 m / 24.9958 m/yr = 100.017 yr.
 # This also serves as a test for the 'darcy velocity' postprocessor, by
-# confirming that the darcy velocity is 24.25 m/yr.
+# confirming that the darcy velocity is 24.9958 m/yr in the y direction, and
+# 0.001 m/yr in the x direction.
 ############### Global parameters
 
 set Dimension                              = 2
@@ -75,9 +77,13 @@ subsection Boundary temperature model
   end
 end
 
-# Free slip boundary on all sides
+# Prescribe a solid x velocity of 0.001 m/yr and a solid
+# y velocity of 0.75 m/yr.
 subsection Boundary velocity model
-  set Tangential velocity boundary indicators = left, right, top, bottom
+  set Prescribed velocity boundary indicators = top: function, bottom: function, left: function, right: function
+  subsection Function
+    set Function expression = 0.001;0.75
+  end
 end
 
 # porosity and bound_fluid are required compositional fields when
@@ -132,7 +138,6 @@ subsection Material model
   # Set the solid density to 3000 kg/m3, and set the minimum/maximum viscosity
   # to 1e21 Pa s for an isoviscous model.
   subsection Visco Plastic
-    set Reference temperature                   = 1600
     set Prefactors for diffusion creep          = 5e-21
     set Viscous flow law                        = diffusion
     set Densities                               = 3000

tests/darcy_convection_step/screen-output

@@ -1,44 +1,59 @@
+-----------------------------------------------------------------------------
+-----------------------------------------------------------------------------
+-----------------------------------------------------------------------------
 
+-----------------------------------------------------------------------------
+-----------------------------------------------------------------------------
 Number of active cells: 4 (on 2 levels)
 Number of degrees of freedom: 134 (50+9+25+25+25)
 
 *** Timestep 0:  t=0 years, dt=0 years
    Solving temperature system... 0 iterations.
    Solving porosity system ... 0 iterations.
    Skipping bound_fluid composition solve because RHS is zero.
-   Solving Stokes system (GMG)... 7+0 iterations.
-      Relative nonlinear residuals (temperature, compositional fields, Stokes system): 6.2054e-17, 1.34414e-16, 0, 5.09696e-16
-      Relative nonlinear residual (total system) after nonlinear iteration 1: 5.09696e-16
+   Solving Stokes system (GMG)... 6+0 iterations.
+      Relative nonlinear residuals (temperature, compositional fields, Stokes system): 6.2054e-17, 1.34414e-16, 0, 1.00007
+      Relative nonlinear residual (total system) after nonlinear iteration 1: 1.00007
 
 
+WARNING: The nonlinear solver in the current timestep failed to converge.
+Acting according to the parameter 'Nonlinear solver failure strategy'...
+Continuing to the next timestep even though solution is not fully converged.
    Postprocessing:
      Writing graphical output: output-darcy_convection_step/solution/solution-00000
 
-*** Timestep 1:  t=103.11 years, dt=103.11 years
+*** Timestep 1:  t=100.017 years, dt=100.017 years
    Solving composition reactions... in 1 substep(s).
    Solving temperature system... 0 iterations.
    Solving porosity system ... 0 iterations.
    Skipping bound_fluid composition solve because RHS is zero.
-   Solving Stokes system (GMG)... 6+0 iterations.
-      Relative nonlinear residuals (temperature, compositional fields, Stokes system): 3.51395e-16, 1.5726e-16, 0, 2.2185e-16
-      Relative nonlinear residual (total system) after nonlinear iteration 1: 3.51395e-16
+   Solving Stokes system (GMG)... 0+0 iterations.
+      Relative nonlinear residuals (temperature, compositional fields, Stokes system): 1.24886e-16, 1.30786e-16, 0, 1.54323e-08
+      Relative nonlinear residual (total system) after nonlinear iteration 1: 1.54323e-08
 
 
    Postprocessing:
 
-*** Timestep 2:  t=200 years, dt=96.8895 years
+*** Timestep 2:  t=200 years, dt=99.9833 years
    Solving composition reactions... in 1 substep(s).
    Solving temperature system... 0 iterations.
    Solving porosity system ... 0 iterations.
    Skipping bound_fluid composition solve because RHS is zero.
-   Solving Stokes system (GMG)... 7+0 iterations.
-      Relative nonlinear residuals (temperature, compositional fields, Stokes system): 1.14854e-16, 1.32969e-16, 0, 3.48944e-16
-      Relative nonlinear residual (total system) after nonlinear iteration 1: 3.48944e-16
+   Solving Stokes system (GMG)... 0+0 iterations.
+      Relative nonlinear residuals (temperature, compositional fields, Stokes system): 1.5766e-16, 4.62514e-16, 0, 1.54323e-08
+      Relative nonlinear residual (total system) after nonlinear iteration 1: 1.54323e-08
 
 
    Postprocessing:
 
 Termination requested by criterion: end time
 
 
++----------------------------------------------+------------+------------+
++----------------------------------+-----------+------------+------------+
++----------------------------------+-----------+------------+------------+
+
 
+WARNING: During this computation 1 nonlinear solver failures occurred!
+-----------------------------------------------------------------------------
+-----------------------------------------------------------------------------

tests/darcy_convection_step/statistics

@@ -13,6 +13,6 @@
 # 13: Velocity iterations in Stokes preconditioner
 # 14: Schur complement iterations in Stokes preconditioner
 # 15: Visualization file name
-0 0.000000000000e+00 0.000000000000e+00 4 59 25 50 1 0 0 0 6 8 8 output-darcy_convection_step/solution/solution-00000 
-1 1.031104829590e+02 1.031104829590e+02 4 59 25 50 1 0 0 0 5 7 7                                                   "" 
-2 2.000000000000e+02 9.688951704104e+01 4 59 25 50 1 0 0 0 6 8 8                                                   "" 
+0 0.000000000000e+00 0.000000000000e+00 4 59 25 50 1 0 0 0          5 7 7 output-darcy_convection_step/solution/solution-00000 
+1 1.000166530498e+02 1.000166530498e+02 4 59 25 50 1 0 0 0 4294967295 0 0                                                   "" 
+2 2.000000000000e+02 9.998334695023e+01 4 59 25 50 1 0 0 0 4294967295 0 0                                                   ""