from __future__ import annotations import unittest from PythonModels.components.amesim_pneumatic import ( HELIUM_PNEUMATIC_GAS, AmesimPneumaticGas, AmesimPneumaticOrifice, AmesimPneumaticVolume, AmesimVariablePneumaticVolume, cm3_to_m3, compressible_orifice_mass_flow, diameter_mm_to_area_m2, kg_to_g, liters_to_m3, m3_to_cm3, mm2_to_m2, ) class AmesimPneumaticComponentsTest(unittest.TestCase): def test_unit_conversions(self) -> None: self.assertAlmostEqual(liters_to_m3(15.0), 0.015) self.assertAlmostEqual(m3_to_cm3(0.015), 15000.0) self.assertAlmostEqual(cm3_to_m3(15000.0), 0.015) self.assertAlmostEqual(kg_to_g(1.25), 1250.0) self.assertAlmostEqual(mm2_to_m2(78.5), 78.5e-6) self.assertAlmostEqual(diameter_mm_to_area_m2(10.0), 7.853981633974483e-5) def test_reference_enthalpy_uses_amesim_operating_temperature_baseline(self) -> None: gas = AmesimPneumaticGas(cp=5193.0, cv=3116.0) self.assertAlmostEqual(gas.specific_reference_enthalpy(298.15), 0.0) self.assertAlmostEqual( gas.specific_reference_enthalpy(290.2036), 5193.0 * (290.2036 - 298.15), ) self.assertAlmostEqual( gas.reference_temperature_from_specific_enthalpy( gas.specific_reference_enthalpy(287.7322), ), 287.7322, ) def test_pressure_reference_enthalpy_includes_real_gas_departure(self) -> None: gas = AmesimPneumaticGas(cp=5193.0, cv=3116.0) ideal_reference_h = gas.specific_reference_enthalpy(287.7322) pressure_reference_h = gas.pressure_reference_enthalpy(13_839_965.0, 287.7322) self.assertAlmostEqual(ideal_reference_h, -54099.6354, delta=0.001) self.assertAlmostEqual( pressure_reference_h - ideal_reference_h, 11936.1, delta=0.1, ) def test_pressure_transport_enthalpy_restores_absolute_energy_offset(self) -> None: gas = HELIUM_PNEUMATIC_GAS pressure = 13_839_965.0 temperature = 287.7322 self.assertAlmostEqual( gas.pressure_transport_enthalpy(pressure, temperature), gas.pressure_reference_enthalpy(pressure, temperature) + gas.cp * 298.15, ) def test_reference_temperature_from_enthalpy_rejects_non_positive_cp(self) -> None: gas = AmesimPneumaticGas(cp=0.0, cv=3116.0) with self.assertRaisesRegex(ValueError, "cp must be positive"): gas.reference_temperature_from_specific_enthalpy(42.0) def test_volume_initial_state_matches_requested_pressure_temperature(self) -> None: volume = AmesimPneumaticVolume.from_liters( name="pn_general_chamber", volume_liters=57.0, p0=15.3e6, T0=293.15, ) props = volume.properties() self.assertAlmostEqual(props.p, 15.3e6, delta=15.3e6 * 1.0e-12) self.assertAlmostEqual(props.T, 293.15) self.assertGreater(props.rho, 20.0) self.assertLess(props.rho, 30.0) def test_volume_reports_amesim_style_observables(self) -> None: volume = AmesimPneumaticVolume.from_liters( name="pn_general_chamber", volume_liters=57.0, p0=15.3e6, T0=293.15, ) self.assertAlmostEqual(volume.volume_cm3(), 57000.0) self.assertAlmostEqual( volume.pressure_gauge_pa(reference_pressure_pa=101_300.0), 15198700.0, ) self.assertGreater(volume.gas_mass_g(), 1300.0) def test_volume_balances_two_connections_with_stream_enthalpy(self) -> None: volume = AmesimPneumaticVolume.from_liters( name="pn_general_chamber", volume_liters=57.0, p0=15.3e6, T0=293.15, ) internal_h = volume.properties().h derivative = volume.derivatives_from_two_connections( port_a_m_flow=0.2, connected_h_a=internal_h + 1000.0, port_b_m_flow=-0.1, connected_h_b=internal_h - 1000.0, internal_h=internal_h, ) self.assertAlmostEqual(derivative.m, 0.1) self.assertAlmostEqual( derivative.U, 0.2 * (internal_h + 1000.0) - 0.1 * internal_h, ) self.assertAlmostEqual(volume.port_a.p, volume.port_b.p) def test_volume_applies_amesim_heat_exchange_to_energy_derivative(self) -> None: volume = AmesimPneumaticVolume.from_liters( name="heated_chamber", volume_liters=15.0, p0=100000.0, T0=300.0, heat_transfer_coefficient=1500.0, heat_transfer_area=0.7, external_temperature_k=293.15, ) props = volume.properties() derivative = volume.derivatives_from_two_connections( port_a_m_flow=0.0, connected_h_a=props.h, port_b_m_flow=0.0, connected_h_b=props.h, internal_h=props.h, ) self.assertAlmostEqual( derivative.U, 1500.0 * 0.7 * (293.15 - 300.0), ) def test_variable_volume_tracks_external_volume(self) -> None: volume = AmesimVariablePneumaticVolume.from_liters( name="pn_c1_8", dead_volume_liters=15.0, p0=100000.0, T0=293.15, ) self.assertAlmostEqual(volume.volume_cm3(), 15000.0) volume.set_external_volume_m3(cm3_to_m3(34242.54636512914)) self.assertAlmostEqual(volume.volume_cm3(), 49242.54636512914) def test_variable_volume_boundary_work_uses_external_volume_rate(self) -> None: volume = AmesimVariablePneumaticVolume.from_liters( name="pn_c1_8", dead_volume_liters=15.0, p0=100000.0, T0=293.15, ) props = volume.properties() volume.set_external_volume_m3(0.0, external_volume_rate_m3_s=2.0e-6) derivative = volume.derivatives_from_two_connections( port_a_m_flow=0.0, connected_h_a=props.h, port_b_m_flow=0.0, connected_h_b=props.h, internal_h=props.h, ) self.assertAlmostEqual(derivative.m, 0.0) self.assertAlmostEqual(derivative.U, -props.p * 2.0e-6) def test_orifice_effective_area_clamps_opening(self) -> None: orifice = AmesimPneumaticOrifice.from_mm2( name="pn_variable_orifice", area_mm2=78.5, opening=1.4, ) self.assertAlmostEqual(orifice.effective_area, 78.5e-6) orifice.opening = -0.25 self.assertAlmostEqual(orifice.effective_area, 0.0) def test_orifice_returns_signed_mass_flow(self) -> None: orifice = AmesimPneumaticOrifice.from_mm2( name="pn_orifice_18", area_mm2=78.5, flow_coefficient=0.9, ) forward = orifice.mass_flow(15.3e6, 1.0e6, 293.15) reverse = orifice.mass_flow(1.0e6, 15.3e6, 293.15) self.assertGreater(forward, 0.0) self.assertAlmostEqual(reverse, -forward) self.assertEqual(orifice.mass_flow(1.0e6, 1.0e6, 293.15), 0.0) def test_choked_flow_is_independent_of_lower_downstream_pressure(self) -> None: base = compressible_orifice_mass_flow( upstream_pressure=15.3e6, downstream_pressure=1.0e6, upstream_temperature=293.15, area=78.5e-6, flow_coefficient=0.9, gas=HELIUM_PNEUMATIC_GAS, ) lower_back_pressure = compressible_orifice_mass_flow( upstream_pressure=15.3e6, downstream_pressure=0.1e6, upstream_temperature=293.15, area=78.5e-6, flow_coefficient=0.9, gas=HELIUM_PNEUMATIC_GAS, ) self.assertGreater(base, 0.0) self.assertAlmostEqual(lower_back_pressure, base) def test_subcritical_flow_decreases_as_back_pressure_rises(self) -> None: low_back_pressure = compressible_orifice_mass_flow( upstream_pressure=1.0e6, downstream_pressure=0.6e6, upstream_temperature=293.15, area=78.5e-6, flow_coefficient=0.9, ) high_back_pressure = compressible_orifice_mass_flow( upstream_pressure=1.0e6, downstream_pressure=0.9e6, upstream_temperature=293.15, area=78.5e-6, flow_coefficient=0.9, ) self.assertGreater(low_back_pressure, high_back_pressure) self.assertGreater(high_back_pressure, 0.0) if __name__ == "__main__": unittest.main()