对齐Amesim氦气PR物性与PNVO流量

tests/test_peng_robinson.py

@@ -19,6 +19,11 @@ class PengRobinsonTest(unittest.TestCase):
         density = HELIUM_PR.density(pressure, temperature)
 
         self.assertGreater(HELIUM_PR.compressibility_factor(pressure, temperature), 1.0)
+        self.assertAlmostEqual(
+            density,
+            24.114225444477153,
+            delta=1.0e-12,
+        )
         self.assertAlmostEqual(
             HELIUM_PR.pressure_from_density(temperature, density),
             pressure,
@@ -28,17 +33,43 @@ class PengRobinsonTest(unittest.TestCase):
     def test_helium_residual_enthalpy_is_small_at_atmosphere(self) -> None:
         self.assertAlmostEqual(
             HELIUM_PR.residual_specific_enthalpy(101_300.0, 298.15),
-            17.834,
+            25.3556466754,
             delta=0.01,
         )
 
     def test_helium_residual_enthalpy_captures_high_pressure_departure(self) -> None:
         self.assertAlmostEqual(
             HELIUM_PR.residual_specific_enthalpy(13_839_965.0, 287.7322),
-            11953.9,
+            12788.0457342,
             delta=0.1,
         )
 
+    def test_residual_isochoric_heat_capacity_is_internal_energy_derivative(
+        self,
+    ) -> None:
+        temperature = 292.3997890954483
+        density = 24.02697515640726
+        temperature_step = 1.0e-3
+        numerical_derivative = (
+            HELIUM_PR.residual_specific_internal_energy_at_density(
+                temperature + temperature_step,
+                density,
+            )
+            - HELIUM_PR.residual_specific_internal_energy_at_density(
+                temperature - temperature_step,
+                density,
+            )
+        ) / (2.0 * temperature_step)
+
+        self.assertAlmostEqual(
+            HELIUM_PR.residual_isochoric_heat_capacity_at_density(
+                temperature,
+                density,
+            ),
+            numerical_derivative,
+            delta=1.0e-6,
+        )
+
     def test_air_reference_remains_available_for_other_models(self) -> None:
         z = AIR_PR.compressibility_factor(101_325.0, 300.0)
         density = AIR_PR.density(101_325.0, 300.0)
@@ -60,7 +91,7 @@ class PengRobinsonTest(unittest.TestCase):
             molar_mass=0.004002602,
             critical_temperature=5.1953,
             critical_pressure=227_460.0,
-            acentric_factor=-0.385,
+            acentric_factor=-0.382,
         )
 
         self.assertAlmostEqual(fluid.specific_gas_constant, 2077.3, delta=0.5)