CompressibleLiquidsCompressible liquid models 
Base classes for compressible liquids 

Cold water model with linear compressibility 

Liquid, linear compressibility water model at 1.01325 bar and 25 degree Celsius 
This information is part of the Modelica Standard Library maintained by the Modelica Association.
The linear compressibility fluid models contained in this package are based on the assumptions that:
This results in models that are only valid for small temperature ranges, but sufficient to model compressibility and e.g., the "water hammer" effect. Another advantage id that only 3 values need to be measured to have an initial model. Hydraulic fluids can often be approximated by this type of model.
That means that the density is a linear function in temperature and in pressure. In order to define the complete model, a number of constant reference values are needed which are computed at the reference values of the states pressure p and temperature T. The model can be interpreted as a linearization of a full nonlinear fluid model (but it is not linear in all thermodynamic coordinates). Reference values are needed for
Apart from that, a user needs to define the molar mass, MM_const. Note that it is possible to define a fluid by computing the reference values from a full nonlinear fluid model by computing the package constants using the standard functions defined in a fluid package (see example in Common, LinearWater_pT).