HIgh pressure zone near the outlet?
 

To finetune the settings for my case (which is a valve) using rhoSimplecFoam, I firstly made a simple tube simulation with similar domain dimensions.

It is a pressure driven flow, the pressures at the inlet and outlet are fixed but the velocities are unkown. Thus I set the inlet pressure and outlet pressure with fixed values.

left side, inlet, high pressure.
right side, outlet, low pressure.

For the inlet U it is a pressureInletVelocity bc, but no matter how I changed the outlet bc, for example, pressureInletOutletVelocity, inletOutlet or zeroGradient, after the pressure gradients builds up, there is a large jump near the outlet, which could be seen in the attached figures.

I guess it is a boundary condition setting problem. But I think the options I tried are the most feasible ones, no other options I could think of.

Any suggestions?

http://www.cfd-online.com/Forums/att...1&d=1369384780

hi
What occurs in jump area if you decrease the outlet pressure?

Immortality,

The outlet pressure should be fixed at this value based on the application requirement. But I will make one case with decreased pressure to spot the problem.

i have a problem like you.
Please let me know how you solved the problem.