Mat. prop. vs Temperature curve approximation
 

Hi,

I want to use the "Expressions" part in the CFX Pre to determine for instance the density vs temperature curve of water! I divided the whole curve in two part and I tried to approximate them by 5th and 6th order polinomes but between the measured points there are unplesaent oscillation! I think (and I experienced too)they cause inconvergency? What sould I do? How can I complete this problem?

Thanks in advence!

Attila