代码仓库移植

tests/cryo_tank/test_integration.py

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+# tests/cryo_tank/test_integration.py
+"""Integration tests for the cryogenic tank simulation."""
+import numpy as np
+from cryo_tank.tank_model import CryoTank
+from cryo_tank.heat_leak import MLIHeatLeak
+from cryo_tank.solver import run
+from cryo_tank.config import (
+    V_TOTAL, H_TANK, P_WORKING, T_INIT, ULLAGE_FRACTION,
+    MDOT_IN_LN2, T_IN_LN2, MDOT_OUT_LN2, T_IN_HE,
+    H_CONV_SURFACE, T_ENV, A_TOTAL,
+)
+
+
+def _make_tank(**overrides):
+    """Create a tank with default config, allowing overrides."""
+    kw = dict(
+        V_total=V_TOTAL, H_tank=H_TANK,
+        P_work=P_WORKING,
+        T_init=T_INIT, ullage_fraction=ULLAGE_FRACTION,
+        mdot_in_ln2=MDOT_IN_LN2, T_in_ln2=T_IN_LN2,
+        mdot_out_ln2=MDOT_OUT_LN2,
+        T_in_he=T_IN_HE,
+        h_conv=H_CONV_SURFACE, T_env=T_ENV,
+        heat_leak_model=MLIHeatLeak(A_total=A_TOTAL, q_mli=1.0),
+    )
+    kw.update(overrides)
+    return CryoTank(**kw)
+
+
+class TestMassConservation:
+
+    def test_liquid_mass_change_matches_net_flow(self):
+        """Over a short run, dm_liq should equal (mdot_in - mdot_out) * dt."""
+        tank = _make_tank()
+        history = run(tank, t_end=10.0, max_step=1.0)
+
+        m_liq_0 = history['m_liq'][0]
+        m_liq_f = history['m_liq'][-1]
+        t_f = history['t'][-1]
+
+        expected_dm = (MDOT_IN_LN2 - MDOT_OUT_LN2) * t_f
+        actual_dm = m_liq_f - m_liq_0
+
+        rel_err = abs(actual_dm - expected_dm) / abs(expected_dm)
+        assert rel_err < 1e-6, f"Mass conservation error: rel_err={rel_err:.2e}"
+
+
+class TestSteadyState:
+
+    def test_zero_flow_zero_leak_is_static(self):
+        """With no flow and no heat leak, state should not change."""
+        tank = _make_tank(
+            mdot_in_ln2=0.0,
+            mdot_out_ln2=0.0,
+            h_conv=0.0,
+            heat_leak_model=MLIHeatLeak(A_total=A_TOTAL, q_mli=0.0),
+        )
+        history = run(tank, t_end=100.0, max_step=10.0)
+
+        T_liq = history['T_liq']
+        T_ull = history['T_ull']
+
+        assert abs(T_liq[-1] - T_liq[0]) < 0.01, f"T_liq drifted: {T_liq[0]:.3f} -> {T_liq[-1]:.3f}"
+        assert abs(T_ull[-1] - T_ull[0]) < 0.1, f"T_ull drifted: {T_ull[0]:.3f} -> {T_ull[-1]:.3f}"
+
+
+class TestPhysicalBehavior:
+
+    def test_liquid_level_decreases(self):
+        """With net outflow, liquid level should decrease."""
+        tank = _make_tank()
+        history = run(tank, t_end=60.0, max_step=5.0)
+        assert history['fill_fraction'][-1] < history['fill_fraction'][0]
+
+    def test_he_flow_rate_positive(self):
+        """He should always flow in (pressurization), not out."""
+        tank = _make_tank()
+        history = run(tank, t_end=60.0, max_step=5.0)
+        assert np.all(history['mdot_He'] >= -1e-10)  # allow tiny numerical noise