interFoam like solvers and pressurized vessel

Ricky-11 · May 24, 2019, 14:17

I'm trying to simulate the discharge of a pressurized liquid from a tank through an orifice using interFoam-like solvers by initializing the volume fraction within the tank to 1 and pressure higher than downstream of the orifice, but once the simulation starts the liquid fraction simply doesn't move.

Also, the discharge must be driven by pressure only and the gravity is set to 0.

Any experience with something like this anybody?

mwaqas · May 28, 2019, 11:45

As it is a single phase flow, I think volume fraction would remain same. Only the pressure or density inside the tank should change. Did you try to visualize your results in paraview?

Ricky-11 · May 28, 2019, 12:56

My thought was the volume fraction would move out of the tank due to the pressure difference across the orifice and yes, I've checked the results in Paraview.

mwaqas · May 29, 2019, 04:16

Fraction is always calculated on the basis of other phase. If there is no other phase, then how can the fraction reduce. Simply, its density will change.

Vol. fraction = Vi / Vt

Both will always remain same. Vt is the total volume at that time, not the initial volume of the phase.

Ricky-11 · June 1, 2019, 07:07

In my understanding, in inter-based solver the volume fraction is calculated from its transport equation and won't change if no phase change phenomena occurs, it will be simply transported by the underlying flow field, which is what I was expecting.

I'll try to explain a bit more the case: let's say we have two plenums connected by a pipe. In the upstream plenum, the pressure of the mixture is higher than in the other plenum. At t=0, the velocity field is zero and the volume fraction is set to 1 in the upstream plenum and to 0 in the pipe and in the downstream plenum.

Shall a velocity field be established by the pressure difference and, as a result, the volume fraction from the upstream plenum convected toward the other one?

May 24, 2019, 14:17	interFoam like solvers and pressurized vessel	#1
Ricky-11 New Member Join Date: Dec 2013 Posts: 11 Rep Power: 12	I'm trying to simulate the discharge of a pressurized liquid from a tank through an orifice using interFoam-like solvers by initializing the volume fraction within the tank to 1 and pressure higher than downstream of the orifice, but once the simulation starts the liquid fraction simply doesn't move. Also, the discharge must be driven by pressure only and the gravity is set to 0. Any experience with something like this anybody?

May 28, 2019, 11:45		#2
mwaqas Senior Member Muhammad Waqas Join Date: Jul 2014 Location: Germany Posts: 122 Rep Power: 12	As it is a single phase flow, I think volume fraction would remain same. Only the pressure or density inside the tank should change. Did you try to visualize your results in paraview?

May 28, 2019, 12:56		#3
Ricky-11 New Member Join Date: Dec 2013 Posts: 11 Rep Power: 12	My thought was the volume fraction would move out of the tank due to the pressure difference across the orifice and yes, I've checked the results in Paraview.

May 29, 2019, 04:16		#4
mwaqas Senior Member Muhammad Waqas Join Date: Jul 2014 Location: Germany Posts: 122 Rep Power: 12	Fraction is always calculated on the basis of other phase. If there is no other phase, then how can the fraction reduce. Simply, its density will change. Vol. fraction = Vi / Vt Both will always remain same. Vt is the total volume at that time, not the initial volume of the phase.

June 1, 2019, 07:07		#5
Ricky-11 New Member Join Date: Dec 2013 Posts: 11 Rep Power: 12	In my understanding, in inter-based solver the volume fraction is calculated from its transport equation and won't change if no phase change phenomena occurs, it will be simply transported by the underlying flow field, which is what I was expecting. I'll try to explain a bit more the case: let's say we have two plenums connected by a pipe. In the upstream plenum, the pressure of the mixture is higher than in the other plenum. At t=0, the velocity field is zero and the volume fraction is set to 1 in the upstream plenum and to 0 in the pipe and in the downstream plenum. Shall a velocity field be established by the pressure difference and, as a result, the volume fraction from the upstream plenum convected toward the other one?