Wrong pressure data/working with reference pressure
 

Dear all,

I'm working on modeling a human aorta, and I'm specifically interested in the pressure data. My process is as follows: I have MRI geometry data of the artery in its lowest pressure state, and i apply a velocity inlet with peak pressure flow speed. The outlets are set to outflow BC. I want to export this pressure data to and apply it as a boundary condition in a mechanical simulation of the previously mentioned geometry.

The problem is, the pressure field I obtain only seems to give me the P, which seems correct, around a 20 mmhg pressure drop, which is expected. But the values range from ~0 to ~-20 while i need them to range from 120mmhg to 100mmhg. Thus I set the reference value too 120mmhg, but this didn't seem to change anything. Does anyone know how to fix this? For the fluid I use a custom Carreau-yasudo model, with only laminar modeling in steady state.

Can someone shed some light on the situation for me? All these different pressures in fluent are very confusing, and when running my mechanical simulation now, the artery shrinks, which is (i think) due to the (delta)negative pressure values obtained by Fluent.

I think, you have to change the operating pressure instead of the reference pressure.