[narendrapatel111]

Hi,

1. What happens if we assign operating pressure location outside the computational domain? As Fluent doesn't show any warning message, does that mean we can assign location outside the domain also?
2. What is difference between total pressure and absolute pressure ?

[AliE]

Hi,

What kind of simulation are you doing? In any case does not make sense define something outside the domain of solution. The solver knows onky the quantities defined in each cell or at the boundaries... Thus if you define something badly, I suspect that fluent makes the decision for you somewhere in a default position.

Total pressure is p+0.5*rho*U^2, while absolute pressure is the pressure added by some reference pressure (e.g. Atmospheric). The total pressure is thus a measure of the energy of the fluid in a point (please remember bernoulli eqution). For incompressible flows, absolute pressure is not import, only the pressure gradient matters.

[narendrapatel111]

Originally Posted by AliE

Hi,

What kind of simulation are you doing? In any case does not make sense define something outside the domain of solution. The solver knows onky the quantities defined in each cell or at the boundaries... Thus if you define something badly, I suspect that fluent makes the decision for you somewhere in a default position.

Total pressure is p+0.5*rho*U^2, while absolute pressure is the pressure added by some reference pressure (e.g. Atmospheric). The total pressure is thus a measure of the energy of the fluid in a point (please remember bernoulli eqution). For incompressible flows, absolute pressure is not import, only the pressure gradient matters.

Hi, thanks for reply. In my simulation, I am not sure that the location I choose to assign operating pressure will be under always lighter fluid, so in that case, where should I assign operating pressure?

[AliE]

Ok but if you don't provide more info about the problem I cannot hive you any suggestion. Can you post a sketch? Usually the pressure is specified at outlet for incompressible flows. If you have a closed box, then a cell at random is fine.