Floting operating pressure
 

Hello I am trying to model pumping water into a closed environment. As it is obvious the temperature increases as the pressure increases in the chamber. In fluent when I chose water as material and set it up the change of rho with pressure using a UDF the "floting operating pressure" option dissapears. It shold be there since there is pressure differences. It appears when I switch from my UDF to ideal-gas conditions, which is a very poor assupmtion to my model. Can anybody look at this case and give me a hint in what I am doing wrong? I am working with water as a material and reaching high pressures as 200 to 300 MPa Thanks in advance Edwardo