Interpolation of gas-liquid multicomponent fluid properties for piping fluid flow analysis

The article proposes the use of bicubic spline interpolation to optimize hydraulic and thermal calculations while processing thermodynamic library data. Research was carried out both in single-phase gas liquid regions, as well two-phase gas-liquid region. accuracy tested for various libraries on multi-component mixtures. Various coordinate systems (P, x), T), H), S) were tested, optimal coordinates grids selected based nature changes thermophysical properties. Experiments conducted range up 80% critical pressure, since near-critical region properties behavior sharply. Plots absolute relative errors also produced a more detailed study determination problem areas where property functions undergo sharp that make difficult. results obtained demonstrate an acceptable level engineering approximation data from libraries.