# IAPWS-IF97 empirical equations for water and steam

IAPWS-IF97 provides empirical equation the dynamic viscosity and the thermal conductivity for water, are there any formulas by IAPWS-IF97 for the density and the specific heat capacity of water?

I found "some" empirical formulas for both, the density and the specific heat capacity of water by going through some papers, but I wonder about recommendations by the IAPWS-IF97 if there is any.

Do you have any recommendation for similar equation for steam?

• How accurate do you need to be? Have you considered using "steam tables" or an equation of state? Jul 17 at 16:39
• @electronpusher I would like to avoid using tables just to make everything $T$ or $P$ or both dependent; in terms of the accuracy, I would like to get "close" to the IAPWS-IF97 values in the region 0 - 150 °C and up to 1 MPa, where the standard EoS may already fail (still even up to 0.4, 0.5 MPa it won't be that accurate). Recently, I found some formula for $C_P$, but I cannot find any for the isochoric heat capacity, and there is no direct (constant) relation to obtain the other from knowing the $C_P$, e.g. Mayer. Jul 18 at 13:48
• I'm guessing the generalization of Meyer's equation is no good without an equation of state. I'm not sure what your options are if theoretical models (EoS) aren't sufficient and you don't want to use tabulated empirical data. Jul 19 at 0:04
• I was also not sure and that's why I asked :), but it's fine, alternatively I can just search though the tables. Jul 19 at 22:54