Hello Joel, thanks for your fast reply! I applied your suggestions and now i am getting simulation results, thanks for that! Ok, i will try to implement my own pump model. I don't want to simulate a correct pump behavior, i just want to bring liquid from one tank to another...

Cheers, Michael

Hi, i try to make a simple model which consists of two tanks which are coupled by a ventil and a pump (see attached model). When i remove the pump, everything is working as expected (the level of tank1 and tank2 adapt to each other when the valve is opend). Now i want to have a pump which should move medium from tank2 to tank1 but i can't get the simulation running. I am using OpenModelica 1.12.0 (64-bit) with solver "dassl"

I already searched the forum, but i didn't found an answer to my problem. I found a similar question with a revised model (Test3-revised.mo) but this also does not work.

Can anyone help me on this topic?

Thanks, Michael
TankDemo.mo