PythonModels/scripts/run_test_mql_full_state_comparison.py

@@ -1544,6 +1544,16 @@ def _pnl0003_energy_diagnostic(
     port_1_flow = snapshot.p4_port3_remote_node_to_orifice_line_flow
     port_2_flow = -snapshot.p4_port3_remote_orifice_to_node_flow
     reference_temperature_k = 298.15
+    pn3_port_2_mass_flow_kg_s = (
+        snapshot.p4_port3_remote_orifice_node_balance.port_2_mass_flow_g_s * 1.0e-3
+    )
+    if abs(pn3_port_2_mass_flow_kg_s) <= 1.0e-12:
+        port_1_connected_h = port_1.h
+    else:
+        port_1_connected_h = (
+            snapshot.p4_port3_remote_orifice_node_balance.port_2_enthalpy_flow_w
+            / pn3_port_2_mass_flow_kg_s
+        )
 
     def amesim_value(data_path: str) -> float:
         return interpolate_series_value(
@@ -1646,7 +1656,7 @@ def _pnl0003_energy_diagnostic(
 
     current_derivative_1, current_derivative_2 = line.derivatives_from_connections(
         port_1_m_flow=port_1_flow,
-        connected_h_1=port_1.h,
+        connected_h_1=port_1_connected_h,
         port_2_m_flow=port_2_flow,
         connected_h_2=connected_port_2.h,
     )
@@ -1675,6 +1685,11 @@ def _pnl0003_energy_diagnostic(
         internal_temperature_k=port_2.T,
         reference_temperature_k=reference_temperature_k,
     )
+    if port_1_flow > 0.0:
+        python_port_1_dh = port_1_flow * (
+            port_1_connected_h - line.gas.cp * reference_temperature_k
+        )
+    else:
         python_port_1_dh = _actual_reference_enthalpy_flow(
             gas=line.gas,
             port_m_flow=port_1_flow,

PythonModels/systems/test_mql_closure.py

@@ -1913,6 +1913,17 @@ class TestMqlPn3P4NodeChamberSegmentClosure:
             port_3_mass_flow_g_s=port_3.port_mass_flow_kg_s * 1.0e3,
         )
 
+    @staticmethod
+    def _pn3_node_port_2_connected_h(
+        *,
+        balance: TestMqlPneumaticNode3Balance,
+        fallback_h: float,
+    ) -> float:
+        mass_flow_kg_s = balance.port_2_mass_flow_g_s * 1.0e-3
+        if abs(mass_flow_kg_s) <= 1.0e-12:
+            return fallback_h
+        return balance.port_2_enthalpy_flow_w / mass_flow_kg_s
+
     @staticmethod
     def _p4_node_port_2_connected_h(
         *,
@@ -2197,10 +2208,15 @@ class TestMqlPn3P4NodeChamberSegmentClosure:
         port_1_flow: float,
         port_2_connected_properties: ThermodynamicProperties,
         port_2_flow: float,
+        port_1_connected_h: float | None = None,
     ) -> tuple[VolumeState, VolumeState]:
         return line.derivatives_from_connections(
             port_1_m_flow=port_1_flow,
-            connected_h_1=port_1_properties.h,
+            connected_h_1=(
+                port_1_properties.h
+                if port_1_connected_h is None
+                else port_1_connected_h
+            ),
             port_2_m_flow=port_2_flow,
             connected_h_2=port_2_connected_properties.h,
         )
@@ -2884,6 +2900,10 @@ class TestMqlPn3P4NodeChamberSegmentClosure:
             port_1_flow=snapshot.p4_port3_remote_node_to_orifice_line_flow,
             port_2_connected_properties=snapshot.p4_port3_remote_primary_line,
             port_2_flow=-snapshot.p4_port3_remote_orifice_to_node_flow,
+            port_1_connected_h=self._pn3_node_port_2_connected_h(
+                balance=snapshot.p4_port3_remote_orifice_node_balance,
+                fallback_h=snapshot.p4_port3_remote_orifice_line_port_1.h,
+            ),
         )
         (
             p4_port3_next_orifice_derivative_1,

tests/test_test_mql_pnl0001_segment.py

@@ -792,6 +792,33 @@ class TestMqlPn3P4NodeChamberSegmentTests(unittest.TestCase):
             ].opening,
             1.0,
         )
+        remote_orifice_line = (
+            closure.pneumatic_closure.components.p4_port3_remote_orifice_line
+        )
+        custom_port_1_h = open_snapshot.p4_port3_remote_orifice_line_port_1.h + 1234.0
+        custom_d1, _ = closure.pneumatic_closure._two_state_connection_line_derivatives(
+            line=remote_orifice_line,
+            port_1_properties=open_snapshot.p4_port3_remote_orifice_line_port_1,
+            port_1_flow=0.01,
+            port_2_connected_properties=open_snapshot.p4_port3_remote_primary_line,
+            port_2_flow=-open_snapshot.p4_port3_remote_orifice_to_node_flow,
+            port_1_connected_h=custom_port_1_h,
+        )
+        expected_custom_d1, _ = remote_orifice_line.derivatives_from_connections(
+            port_1_m_flow=0.01,
+            connected_h_1=custom_port_1_h,
+            port_2_m_flow=-open_snapshot.p4_port3_remote_orifice_to_node_flow,
+            connected_h_2=open_snapshot.p4_port3_remote_primary_line.h,
+        )
+        default_d1, _ = closure.pneumatic_closure._two_state_connection_line_derivatives(
+            line=remote_orifice_line,
+            port_1_properties=open_snapshot.p4_port3_remote_orifice_line_port_1,
+            port_1_flow=0.01,
+            port_2_connected_properties=open_snapshot.p4_port3_remote_primary_line,
+            port_2_flow=-open_snapshot.p4_port3_remote_orifice_to_node_flow,
+        )
+        self.assertAlmostEqual(custom_d1.U, expected_custom_d1.U)
+        self.assertNotAlmostEqual(custom_d1.U, default_d1.U)
         closure.snapshot_at(0.0, state)
         self.assertAlmostEqual(
             self.system.pneumatic_assembly.variable_orifices[