From 4f34788e2e36225cef6f081df55c42eac822defc Mon Sep 17 00:00:00 2001
From: Christopher Neal <chrisneal@snumerics.com>
Date: Fri, 29 Sep 2023 18:14:41 -0400
Subject: [PATCH] small formatting changes & comments

---
 src/oneD/Boundary1D.cpp | 10 ++++++----
 src/oneD/StFlow.cpp     | 27 ++++++++++++++++-----------
 2 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/src/oneD/Boundary1D.cpp b/src/oneD/Boundary1D.cpp
index 50ef33e7853..7bd6760b23f 100644
--- a/src/oneD/Boundary1D.cpp
+++ b/src/oneD/Boundary1D.cpp
@@ -210,7 +210,7 @@ void Inlet1D::eval(size_t jg, double* xg, double* rg,
             // spreading rate. The flow domain sets this to V(0),
             // so for finite spreading rate subtract m_V0.
             rb[c_offset_V] -= m_V0;
-        } else {
+        } else { //unstrained flow
             rb[c_offset_U] = m_flow->density(0) * xb[c_offset_U] - m_mdot;
         }
 
@@ -235,10 +235,12 @@ void Inlet1D::eval(size_t jg, double* xg, double* rg,
             rb[c_offset_T] -= m_flow->T_fixed(m_flow->nPoints() - 1);
         }
 
-        // For point control adjustments
-        if (m_flow->twoPointControlEnabled()) {
+        
+        if (m_flow->twoPointControlEnabled()) {// For point control adjustments
+            // At the right boundary, the mdot is dictated by the velocity at the
+            // right boundary, which comes from the Uo variable. 
             m_mdot = -(m_flow->density(last_index) * xb[c_offset_Uo]);
-            rb[c_offset_U] += m_mdot; // u
+            rb[c_offset_U] += m_mdot; 
         } else {
             rb[c_offset_U] += m_mdot;
             rb[c_offset_Uo] += m_mdot/m_flow->density(last_index);
diff --git a/src/oneD/StFlow.cpp b/src/oneD/StFlow.cpp
index 837156559a5..2920b6b5535 100644
--- a/src/oneD/StFlow.cpp
+++ b/src/oneD/StFlow.cpp
@@ -412,6 +412,7 @@ void StFlow::evalContinuity(double* x, double* rsd, int* diag,
         rsd[index(c_offset_U,jmin)] = -(rho_u(x,jmin + 1) - rho_u(x,jmin))/m_dz[jmin]
                                       -(density(jmin + 1)*V(x,jmin + 1)
                                       + density(jmin)*V(x,jmin));
+        
         diag[index(c_offset_U,jmin)] = 0; // Algebraic constraint
     }
 
@@ -435,6 +436,7 @@ void StFlow::evalContinuity(double* x, double* rsd, int* diag,
             // in the opposite direction.
             rsd[index(c_offset_U,j)] = -(rho_u(x,j+1) - rho_u(x,j))/m_dz[j]
                                        -(density(j+1)*V(x,j+1) + density(j)*V(x,j));
+            
             diag[index(c_offset_U, j)] = 0; // Algebraic constraint
         }
     } else if (m_isFree) { // "free-flow"
@@ -506,7 +508,7 @@ void StFlow::evalLambda(double* x, double* rsd, int* diag,
  
     if (jmin == 0) { // left boundary
         if (m_twoPointControl) {
-            rsd[index(c_offset_L, jmin)] = lambda(x,1) - lambda(x,0);
+            rsd[index(c_offset_L, jmin)] = lambda(x,jmin+1) - lambda(x,jmin);
         } else {
             rsd[index(c_offset_L, jmin)] = -rho_u(x, jmin);
         }
@@ -586,6 +588,9 @@ void StFlow::evalUo(double* x, double* rsd, int* diag,
     }
 
     if (jmin == 0) { // left boundary
+        // Because the Uo equation is used for two-point control, the boundary
+        // for Uo is located in the domain interior at the right control point,
+        // thus at the boundary, the 
         rsd[index(c_offset_Uo,jmin)] = Uo(x,jmin+1) - Uo(x,jmin);
     }
 
@@ -867,14 +872,14 @@ AnyMap StFlow::getMeta() const
         state["fixed-point"]["temperature"] = m_tfixed;
     }
 
-    // // One and two-point control meta data
-    // if (m_twoPointControl) {
-    //     state["point-control"]["type"] = "two-point";
-    //     state["point-control"]["left-location"] = m_zLeft;
-    //     state["point-control"]["right-location"] = m_zRight;
-    //     state["point-control"]["left-temperature"] = m_tLeft;
-    //     state["point-control"]["right-temperature"] = m_tRight;
-    // }
+    // Two-point control meta data
+    if (m_twoPointControl) {
+        state["point-control"]["type"] = "two-point";
+        state["point-control"]["left-location"] = m_zLeft;
+        state["point-control"]["right-location"] = m_zRight;
+        state["point-control"]["left-temperature"] = m_tLeft;
+        state["point-control"]["right-temperature"] = m_tRight;
+    }
 
     return state;
 }
@@ -998,7 +1003,7 @@ void StFlow::setMeta(const AnyMap& state)
         m_tfixed = state["fixed-point"]["temperature"].asDouble();
     }
 
-    /* // Two-point control meta data
+    // Two-point control meta data
     if (state.hasKey("point-control")) {
         const AnyMap& pc = state["point-control"].as<AnyMap>();
         if (pc["type"] == "two-point") {
@@ -1008,7 +1013,7 @@ void StFlow::setMeta(const AnyMap& state)
             m_tLeft = pc["left-temperature"].asDouble();
             m_tRight = pc["right-temperature"].asDouble();
         }
-    } */
+    }
 }
 
 void StFlow::solveEnergyEqn(size_t j)