[FeveR]

Hello everyone,
I'm new user on the forum but I read a lot of topics here and I don't have an idea how to solve my problem. Maybe someone can help me how to solve it.
I want to check the water flow through the jet ski pump, impeller is rotating about 8000RPM. I'm trying to solve it using "Rotating region", when I use moving wall it takes about 12 hours to count 1 iteration. I tried doing external and internal flows, fine mesh, I don't have cavitation turned on, exclude cavities without flow conditions is unchecked, laminar and turbulent flow type, using k-epsilion parameters and my problem is always the same - I'm getting a negative pressure in front of impeller, about -400000Pa. I think it is inconsisten with the laws of physics. Is there anybody who can help me ? Maybe I miss something in settings..
Screen with results:
https://gyazo.com/3237c460528ae34b17509e5f5443168a

Best regards,
Patryk