The Second Virial Coefficient of Ordinary Water Substance: A New Correlation

It is shown that the specific second virial coefficient for ordinary water substance, expressed as a function of temperature, is correlated by This correlation, motivated by recent observations from low-pressure steady-flow calorimetry from 20°C to 140°C, also covers older tabulated values of the second virial coefficient extending to 800°C. The Boyle temperature is found to be 1498 K. B2 = a1 f1 + a2 f2 + a3 f3 where f1 = 1/(1 + T/α), f2 = (1 - e-β/ T)5/2( T/β)1/2eβ/ T, f3 = β/ T, α = 10000 K, β = 1500 K, a1 = 0.0015 m3/kg, a2 = −0.000942 m3/kg and a3 = −0.0004882 m3/kg.