Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(10)

Published: Oct. 1, 2024

Isentropic processes are crucial in engineering as they represent idealized and serve reference conditions for thermodynamic analyses. Existing methods calculating isentropic non-ideal fluids either too slow practical applications [equation of state (EOS) approach] or inaccurate (classic modified polytropic isentrope equation: Pvκ=Const. where exponent κ is the expansion coefficient). This paper proposes a novel equation, Pvλ=Const., with path-specific λ correcting variation generic fluid processes. The benefit this approach that it maintains equation's form, so explicit relations can be derived, enabling straightforward rapid calculations better physical understanding. Using supercritical carbon dioxide to test hypothesis, proposed accurately calculate stagnation within 2% exact EOS calculation, whereas classic have errors up 50%. Additionally, fitted function approximately 15–20 times faster than approach. Moreover, results two other fluids, hexamethyldisiloxane R-143a, included prove robustness general applicability equations. method strikes balance between accuracy, simplicity, computational speed offering greatly simplified expressions thermodynamics modeling such turbomachinery reduced-order models design optimizations.

Language: Английский