Two-fluid effective viscosity: arithmetic & harmonic options

siddanib · Jul 16, 2024 · 9d58cd7 · 9d58cd7
1 parent 9d5b42f
commit 9d58cd7
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Showing 3 changed files with 11 additions and 2 deletions.
diff --git a/src/incflo.H b/src/incflo.H
@@ -549,6 +549,7 @@ private:
     amrex::Real m_eta_max = amrex::Real(1.0e+20);
     // Adding properties for a second fluid
     bool m_two_fluid = false;
+    bool m_two_fluid_eta_harmonic = false;
     amrex::Real m_ro_0_second = 1.0;
     FluidModel m_fluid_model_second;
     amrex::Real m_mu_second = 1.0;

diff --git a/src/rheology/incflo_rheology.cpp b/src/rheology/incflo_rheology.cpp
@@ -506,13 +506,20 @@ void incflo::compute_nodal_viscosity_at_level (int /*lev*/,
            Array4<Real const> const& eta_arr_second = vel_eta_second.const_array(mfi);
            Array4<Real> const& eta_arr = vel_eta->array(mfi);
            const Real min_conc_scnd = m_min_conc_second;
+           const bool eta_harmonic = m_two_fluid_eta_harmonic;
            amrex::ParallelFor(bx, [=] AMREX_GPU_DEVICE (int i, int j, int k) noexcept
            {
               if (conc_second_arr(i,j,k) > min_conc_scnd) {
                 // Using weighted harmonic mean for vel_eta
-                eta_arr(i,j,k) = ((Real(1.0)-conc_second_arr(i,j,k))/eta_arr(i,j,k))
+                if (eta_harmonic) {
+                    eta_arr(i,j,k) = ((Real(1.0)-conc_second_arr(i,j,k))/eta_arr(i,j,k))
                                   + (conc_second_arr(i,j,k)/eta_arr_second(i,j,k));
-                eta_arr(i,j,k) = Real(1.0)/eta_arr(i,j,k);
+                    eta_arr(i,j,k) = Real(1.0)/eta_arr(i,j,k);
+                }
+                else {
+                    eta_arr(i,j,k) = (Real(1.0)-conc_second_arr(i,j,k))*eta_arr(i,j,k) +
+                                     conc_second_arr(i,j,k)*eta_arr_second(i,j,k);
+                }
               }
            });
        }

diff --git a/src/setup/init.cpp b/src/setup/init.cpp
@@ -142,6 +142,7 @@ void incflo::ReadParameters ()
 
         // Check if there is a second fluid
         pp.query("two_fluid", m_two_fluid);
+        pp.query("two_fluid_eta_harmonic",m_two_fluid_eta_harmonic);
 
         // Density (if constant)
         pp.query("ro_0", m_ro_0);