Positive Pressure ang negative Pressure
 

Hi, dear all

I have modelled external flow around building and I found that there are positive pressure and negative pressure. What's the meaning of the negative pressure and possitive pressure? Is it according with x, y, z direction? or positive pressure for compress and negative pressure for suction, is it right?

Thank's before....

Pressures are measured relative to a reference pressure, 1 atmosphere by default.

Dear Glenn,

Would you like give more explanation about this?

Thank you

It is a pretty basic concept and well described in the documentation. Read about reference pressure in CFX help.