Hi there I need to set the material "water-liquid" to compressible for a evalution of the wavereflexionlaw in my Geometrie. If I simulate it with Air all works great. just need to get a wave into water. I tried it with a udf "pressure depended density" but I don't get a wave into the system.

thx

A ben voilà on cherche de l'aide?

Fluent treats all liquids as incompressible. Hence, the only possibility is--as you already tried--to write your own udf. Special care must also be given to the numerics since you have a hyperbolic (equations) problem. Good Luck!

Philipp

Thx Philipp Beierer As I changed the solver to "coupled implicit" my problem was solved. the udf was causing the divergence. Now it works.