Negative pressure
 

This might seem silly to some guys. I am doing a fuel cell project. I have two flow channels. The problem I am facing is that I get negative absolute pressures on one of the flows(I do see velocities on both the sides). I don't know what the problem is. Please give me an idea as to what I am doing wrong.

Re: Negative pressure
 

Check the physics of the model. Check if there is any phase change. If you do not model this you may get the negative pressure. e.g. cavitation in case of liquid fluids. If the fluid is gaseous, switch on compressibility.

Secondly wait to get the full convergence. It may vanish after some time.

Hope this helps