[groovyBC] How to implement Inlet velocity which varies with the pressure?

fchagas · August 22, 2019, 14:21

Hello guys,

I am trying to implement in openfoam a boundary condition with the groovyBC tool.

I'm using interFoam to study a two-phase gas-liquid flow, where initially there was only liquid and the gas comes in after a certain period.

In my problem, inlet velocity depends on the hydrostatic pressure in the inlet, which in turn varies according to the amount of gas that enters the domain.

That is, the inlet velocity which the gas enters depends on the pressure, which in turn depends on the amount of gas that has already entered the domain.

The equation is the following:

Q=2*pi*k*H*(Pform-Pbot)/(mi*log(d1/d2))

Where pi,k,H,Pform,d1 and d2 are CONSTANT values, and Pbot is suppose to be the hydrostatic pressure in front of the inlet boundary face.

My question is:

How do I use the pressure field calculated by interfoam at each moment, to use in the referred equation and find the value of variable Q?

Thanks in advance!!

fchagas · September 3, 2019, 21:30

Thank you all. I've got it.

lvzy · October 11, 2020, 22:18

I encountered the same problem as you. When setting the boundary condition of scalar C, the value of scalar B is needed, and B is updated over time. How do I get the value of B when setting the boundary condition of C?

August 22, 2019, 14:21	[groovyBC] How to implement Inlet velocity which varies with the pressure?	#1
fchagas New Member Felipe Chagas Join Date: Feb 2019 Posts: 11 Rep Power: 7	Hello guys, I am trying to implement in openfoam a boundary condition with the groovyBC tool. I'm using interFoam to study a two-phase gas-liquid flow, where initially there was only liquid and the gas comes in after a certain period. In my problem, inlet velocity depends on the hydrostatic pressure in the inlet, which in turn varies according to the amount of gas that enters the domain. That is, the inlet velocity which the gas enters depends on the pressure, which in turn depends on the amount of gas that has already entered the domain. The equation is the following: Q=2pikH(Pform-Pbot)/(mi*log(d1/d2)) Where pi,k,H,Pform,d1 and d2 are CONSTANT values, and Pbot is suppose to be the hydrostatic pressure in front of the inlet boundary face. My question is: How do I use the pressure field calculated by interfoam at each moment, to use in the referred equation and find the value of variable Q? Thanks in advance!!

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September 3, 2019, 21:30		#2
fchagas New Member Felipe Chagas Join Date: Feb 2019 Posts: 11 Rep Power: 7	Thank you all. I've got it.

October 11, 2020, 22:18		#3
lvzy New Member zhuoyao lv Join Date: May 2020 Posts: 1 Rep Power: 0	I encountered the same problem as you. When setting the boundary condition of scalar C, the value of scalar B is needed, and B is updated over time. How do I get the value of B when setting the boundary condition of C?