Base number of substeps on a theoretical max. (erf-model#2007)

* Base number of substeps on a theoretical max. * Update based upon slack convo. * Make failing tests use 6 substeps.
ewquon · Dec 9, 2024 · fdb8336 · fdb8336
1 parent e8c3bd5
commit fdb8336
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Showing 5 changed files with 8 additions and 4 deletions.
diff --git a/Source/TimeIntegration/ERF_ComputeTimestep.cpp b/Source/TimeIntegration/ERF_ComputeTimestep.cpp
@@ -201,7 +201,9 @@ ERF::estTimeStep (int level, long& dt_fast_ratio) const
          if (fixed_dt[level] > 0. && fixed_fast_dt[level] > 0.) {
              dt_fast_ratio = static_cast<long>( fixed_dt[level] / fixed_fast_dt[level] );
          } else if (fixed_dt[level] > 0.) {
-             dt_fast_ratio = static_cast<long>( 6 );
+             // Max CFL_c = 1.0 for substeps, but we enforce a min of 4 substeps
+             auto dt_sub_max = (estdt_comp/cfl);
+             dt_fast_ratio = static_cast<long>( std::max(fixed_dt[level]/dt_sub_max,4.) );
          }
 
          // Force time step ratio to be an even value

diff --git a/Tests/test_files/ABL_InflowFile/ABL_InflowFile.i b/Tests/test_files/ABL_InflowFile/ABL_InflowFile.i
@@ -28,6 +28,7 @@ zhi.type = "SlipWall"
 
 # TIME STEP CONTROL
 erf.fixed_dt = 0.1  # fixed time step depending on grid resolution
+erf.fixed_mri_dt_ratio = 6
 
 # DIAGNOSTICS & VERBOSITY
 erf.sum_interval   = 1       # timesteps between computing mass

diff --git a/Tests/test_files/MSF_Sub_IsentropicVortexAdv/MSF_Sub_IsentropicVortexAdv.i b/Tests/test_files/MSF_Sub_IsentropicVortexAdv/MSF_Sub_IsentropicVortexAdv.i
@@ -20,7 +20,8 @@ zhi.type = "SlipWall"
 # TIME STEP CONTROL
 erf.substepping_type = Implicit
 erf.fixed_dt         = 0.0003
-
+erf.fixed_mri_dt_ratio = 6
+    
 # DIAGNOSTICS & VERBOSITY
 erf.sum_interval    = 1       # timesteps between computing mass
 erf.v               = 1       # verbosity in ERF.cpp

diff --git a/Tests/test_files/TaylorGreenAdvecting/TaylorGreenAdvecting.i b/Tests/test_files/TaylorGreenAdvecting/TaylorGreenAdvecting.i
@@ -15,7 +15,7 @@ zhi.type = "SlipWall"
 
 # TIME STEP CONTROL
 erf.fixed_dt           = 0.16    # fixed time step
-erf.mri_fixed_dt_ratio = 4
+erf.fixed_mri_dt_ratio = 6
 
 # DIAGNOSTICS & VERBOSITY
 erf.sum_interval   = 1       # timesteps between computing mass

diff --git a/Tests/test_files/TaylorGreenAdvectingDiffusing/TaylorGreenAdvectingDiffusing.i b/Tests/test_files/TaylorGreenAdvectingDiffusing/TaylorGreenAdvectingDiffusing.i
@@ -15,7 +15,7 @@ zhi.type = "SlipWall"
 
 # TIME STEP CONTROL
 erf.fixed_dt           = .16    # fixed time step
-erf.mri_fixed_dt_ratio = 4
+erf.fixed_mri_dt_ratio = 6
 
 # DIAGNOSTICS & VERBOSITY
 erf.sum_interval   = 1       # timesteps between computing mass