Boundary conditions in a pipe

sadzikk · February 28, 2021, 06:27

Dear All,
I'm trying to proceed the simulation in a syphon. I'd like it to be transient simulation of two fluid - water and air. I tried to set opening in inlet with mass and momentum option - opening pres. and dirn and the same option for outlet but there is a warning "the solver failed with a non-zero exit code:2". The same warning occurs when I tried to set opening in inlet and boundary type in outlet. I have no idea where is a problem and how to fix i :<

sasanghomi · February 28, 2021, 07:23

Hi,

Why are you using Opening Boundary condition in Inlet Boundary? Switch to Inlet B.C and fix the mass flow rate. Also, it is better not to force the direction of flow in the outlet boundary condition.

Gert-Jan · February 28, 2021, 09:20

This is not a simple calcultion. The boundary orientation and ssecification need to be defined with great care. So, please show the exact geometry and your BC settings (= upload the output file).

February 28, 2021, 06:27	Boundary conditions in a pipe	#1
sadzikk New Member Daria Join Date: Feb 2021 Posts: 1 Rep Power: 0	Dear All, I'm trying to proceed the simulation in a syphon. I'd like it to be transient simulation of two fluid - water and air. I tried to set opening in inlet with mass and momentum option - opening pres. and dirn and the same option for outlet but there is a warning "the solver failed with a non-zero exit code:2". The same warning occurs when I tried to set opening in inlet and boundary type in outlet. I have no idea where is a problem and how to fix i :<

February 28, 2021, 07:23		#2
sasanghomi Senior Member Sasan Ghomi Join Date: Sep 2012 Location: Denmark Posts: 292 Rep Power: 15	Hi, Why are you using Opening Boundary condition in Inlet Boundary? Switch to Inlet B.C and fix the mass flow rate. Also, it is better not to force the direction of flow in the outlet boundary condition. __________________ Best regards, Sasan Ghomi

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February 28, 2021, 09:20		#3
Gert-Jan Senior Member Gert-Jan Join Date: Oct 2012 Location: Europe Posts: 1,928 Rep Power: 28	This is not a simple calcultion. The boundary orientation and ssecification need to be defined with great care. So, please show the exact geometry and your BC settings (= upload the output file).