接入test_mql pneumatic_69传输焓RHS

tests/test_amesim_pnl0001_pipe.py

@@ -115,6 +115,29 @@ class AmesimPnl0001PipeTests(unittest.TestCase):
             - 0.1 * internal.u,
         )
 
+    def test_transport_enthalpy_derivative_preserves_pn2vol_energy_basis(self) -> None:
+        internal = self.pipe.properties()
+        derivative = self.pipe.derivatives_from_transport_enthalpy_connections(
+            port_1_m_flow=0.2,
+            connected_h_1=internal.h + 1000.0,
+            port_2_m_flow=-0.1,
+            connected_h_2=internal.h - 1000.0,
+        )
+
+        self.assertAlmostEqual(derivative.m, 0.1)
+        self.assertAlmostEqual(
+            derivative.U,
+            0.2 * (internal.h + 1000.0) - 0.1 * internal.h,
+        )
+        temperature_derivative = (
+            derivative.U - internal.u * derivative.m
+        ) / (self.pipe.state.m * self.pipe.gas.cv)
+        expected_temperature_derivative = (
+            0.2 * (internal.h + 1000.0 - internal.u)
+            - 0.1 * (internal.h - internal.u)
+        ) / (self.pipe.state.m * self.pipe.gas.cv)
+        self.assertAlmostEqual(temperature_derivative, expected_temperature_derivative)
+
 
 if __name__ == "__main__":
     unittest.main()