Thermodynamic Operations

Thermodynamic operations execute equilibrium and property tasks using a configured fluid. Most workflows create a ThermodynamicOperations object once and reuse it for multiple calls.

Flash Calculations

• TPflash(): Calculates phase split at specified temperature and pressure. Run initProperties() afterward for density/viscosity.
• PHflash(H) and PSflash(S): Solve for temperature/phase split given enthalpy or entropy targets—useful for compressors and turbines. Set the pressure on the fluid with setPressure() before calling these.
• TVflash(V): Volume-constrained flash—finds pressure at fixed temperature and total volume.
• VUflash(V, U): Volume- and internal-energy-constrained flash for transient simulations.

ThermodynamicOperations ops = new ThermodynamicOperations(fluid);
ops.TPflash();
double vaporFraction = fluid.getBeta();

Phase Envelopes

• PT envelope: ops.calcPTphaseEnvelope() fills critical point, cricondenbar, cricondentherm, and two-phase boundary.
• Hydrate curves: Enable hydrateCheck(true) before calling ops.hydrateFormationTemperature(pressure).
• Wax/solid envelopes: Use a solid-enabled system and call ops.calcSolidFormationTemperature().

Property Routines

After flashes, properties are available on each phase:

• getDensity() or getNumberOfMoles() for molar/volume properties.
• getEnthalpy(), getEntropy(), and getCp() for energy balances.
• getViscosity(), getThermalConductivity(), and getInterfacialTension() for transport analyses.

Electrolytes and Reactions

• Electrolytes: Build systems such as SystemFurstElectrolyteEos or SystemElectrolyteCPAstatoil, add salts/acids, and enable charge balance. Use ops.electrolyteFlash() for salt precipitation studies.
• Chemical reactions: Define reactions with stoichiometry and equilibrium constants, then call ops.calcChemicalEquilibrium() to couple them into flashes.

Best Practices

• Always reinitialize (fluid.init(3)) after changing temperature, pressure, or composition significantly.
• Reuse the same ThermodynamicOperations instance when sweeping conditions to avoid rebuilding internal caches.
• For performance-sensitive loops, pre-allocate fluids and avoid repeated parsing of the component database.