对齐PNVO近等压层流平滑

app/simulation/components/amesim/flow/orifices.py

@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 from collections.abc import Mapping
-from math import isclose, sqrt
+from math import isclose, log, sqrt, tanh
 
 from app.simulation.components.amesim.gases import (
     AMESIM_GAS_INDEX_PARAMETER,
@@ -32,6 +32,8 @@ _FLOW_COEFFICIENT_OPTIONS = (
 _FLOWSET_USES_CQ = (ParameterCondition("flowset", (1.0,)),)
 _FLOWSET_USES_CV = (ParameterCondition("flowset", (2.0,)),)
 _FLOWSET_USES_KV = (ParameterCondition("flowset", (3.0,)),)
+_PN_PRESSURE_RATIO_ACCURACY = 0.9999
+_PN_LAMINAR_SMOOTHING_GAIN = 12.0
 _PNOR001_FLOW_COEFFICIENT_GROUP = ParameterGroupDisplaySpec(
     id="flow_coefficient",
     label="流量系数",
@@ -565,6 +567,31 @@ class AmesimPnvo001FixedOpening(AlgebraicComponent):
             1.0,
         )
 
+    @staticmethod
+    def _subsonic_mass_flow_parameter(
+        *,
+        pressure_ratio: float,
+        gamma_s: float,
+        density: float,
+        upstream_temperature: float,
+        upstream_pressure: float,
+    ) -> float:
+        expansion = (
+            pressure_ratio ** (2.0 * gamma_s)
+            - pressure_ratio ** (1.0 + gamma_s)
+        )
+        return sqrt(
+            max(
+                2.0
+                / (1.0 - gamma_s)
+                * density
+                * upstream_temperature
+                / upstream_pressure
+                * expansion,
+                0.0,
+            )
+        )
+
     def mass_flow(self, p_2: float, p_3: float) -> float:
         if p_2 == p_3 or self.effective_area == 0.0:
             return 0.0
@@ -602,6 +629,7 @@ class AmesimPnvo001FixedOpening(AlgebraicComponent):
             1.0 / (1.0 - gamma_s)
         )
         if pressure_ratio <= critical_ratio:
+            effective_pressure_ratio = critical_ratio
             mass_flow_parameter = (
                 sqrt(2.0 / (1.0 + gamma_s) * density * T_up / p_up)
                 * (2.0 * gamma_s / (gamma_s + 1.0))
@@ -611,20 +639,13 @@ class AmesimPnvo001FixedOpening(AlgebraicComponent):
                 2.0 / (1.0 + gamma_s) * p_up / density
             )
         else:
-            expansion = (
+            effective_pressure_ratio = pressure_ratio
-                pressure_ratio ** (2.0 * gamma_s)
+            mass_flow_parameter = self._subsonic_mass_flow_parameter(
-                - pressure_ratio ** (1.0 + gamma_s)
+                pressure_ratio=pressure_ratio,
-            )
+                gamma_s=gamma_s,
-            mass_flow_parameter = sqrt(
+                density=density,
-                max(
+                upstream_temperature=T_up,
-                    2.0
+                upstream_pressure=p_up,
-                    / (1.0 - gamma_s)
-                    * density
-                    * T_up
-                    / p_up
-                    * expansion,
-                    0.0,
-                )
             )
             gas_velocity = sqrt(
                 max(
@@ -636,6 +657,29 @@ class AmesimPnvo001FixedOpening(AlgebraicComponent):
                     0.0,
                 )
             )
+
+        # AMESim's gas_cm_prc_ applies this factor continuously over the
+        # complete pressure-ratio range. It is effectively one outside the
+        # near-equal-pressure region and makes Cm (and vena-contracta
+        # velocity) approach zero quadratically as the pressure ratio tends
+        # to one. The reference Cm intentionally reuses the current gamma_s.
+        reference_mass_flow_parameter = self._subsonic_mass_flow_parameter(
+            pressure_ratio=_PN_PRESSURE_RATIO_ACCURACY,
+            gamma_s=gamma_s,
+            density=density,
+            upstream_temperature=T_up,
+            upstream_pressure=p_up,
+        )
+        if mass_flow_parameter > 0.0 and reference_mass_flow_parameter > 0.0:
+            smoothing_argument = (
+                _PN_LAMINAR_SMOOTHING_GAIN
+                * abs(mass_flow_parameter / reference_mass_flow_parameter)
+                * log(effective_pressure_ratio)
+                / log(_PN_PRESSURE_RATIO_ACCURACY)
+            )
+            smoothing_factor = tanh(max(smoothing_argument, 0.0))
+            mass_flow_parameter *= smoothing_factor
+            gas_velocity *= smoothing_factor
         return mass_flow_parameter, gas_velocity
 
     def _one_way_mass_flow(

tests/test_amesim_pnvo001_fixed_component.py

@@ -144,6 +144,96 @@ class AmesimPnvo001FixedOpeningComponentTests(unittest.TestCase):
             delta=1.0e-8,
         )
 
+    def test_helium_laminar_transition_matches_amesim_baseline(self) -> None:
+        medium = AmesimHeliumPengRobinsonMedium()
+        valve = AmesimPnvo001FixedOpening(
+            "valve_1",
+            medium,
+            cq=0.45,
+            area0=78.5e-6,
+            opening=1.0,
+        )
+        cases = (
+            # p_up [PaA], p_down [PaA], T_up [K], dm [g/s], Cm, velocity [m/s]
+            (
+                10_837_357.913884956,
+                10_835_428.362241976,
+                255.45507181057303,
+                9.770711291393273,
+                4.07922685863417e-4,
+                13.951480313568323,
+            ),
+            (
+                10_735_827.842429036,
+                10_735_543.135671863,
+                254.49635939397584,
+                3.4711877823059916,
+                1.4601624857015259e-4,
+                4.982778680076626,
+            ),
+            (
+                10_703_773.135050302,
+                10_703_621.857082237,
+                254.1925398502598,
+                1.53560321377487,
+                6.475023461883112e-5,
+                2.208065833961227,
+            ),
+            (
+                10_682_359.261700785,
+                10_682_301.022976216,
+                253.98926908210996,
+                0.25626141624058846,
+                1.0822847918204546e-5,
+                0.36890236539556787,
+            ),
+            (
+                10_678_100.351449525,
+                10_678_093.704329137,
+                253.94881208705195,
+                0.0033658306146710985,
+                1.421965896377586e-7,
+                0.004846389527047451,
+            ),
+        )
+
+        for (
+            p_up,
+            p_down,
+            T_up,
+            expected_dm,
+            expected_cm,
+            expected_velocity,
+        ) in cases:
+            with self.subTest(pressure_difference=p_up - p_down):
+                mass_flow_parameter, gas_velocity = (
+                    valve._one_way_flow_characteristics(
+                        upstream_pressure=p_up,
+                        downstream_pressure=p_down,
+                        upstream_temperature=T_up,
+                    )
+                )
+                mass_flow_g_s = (
+                    valve._one_way_mass_flow(
+                        upstream_pressure=p_up,
+                        downstream_pressure=p_down,
+                        upstream_temperature=T_up,
+                    )
+                    * 1.0e3
+                )
+
+                self.assertAlmostEqual(mass_flow_g_s, expected_dm, delta=1.0e-11)
+                self.assertAlmostEqual(
+                    mass_flow_parameter,
+                    expected_cm,
+                    delta=1.0e-15,
+                )
+                self.assertAlmostEqual(
+                    gas_velocity,
+                    expected_velocity,
+                    delta=5.0e-10,
+                )
+
 
 if __name__ == "__main__":
     unittest.main()