Pressure-outlet temperature problem

sfawn · January 19, 2024, 07:21

Hello,

I've got a 2d multi-phase flow with 3 phases: argon, liquid "frozen" copper and liquid "frozen" chromium (I am doing solidfication and melting simulation and at the initialization the temperature is below the melting point of both metals).

The initialization is shown on the attached image, but when I run the simulation for 4 timesteps (my energy source term turns on at the 5th time step), I don't understand why I get some copper on the gas boundary, which also have a temperature of 300K (which was my initial temperature before, but I changed the material reference temperatures of copepr and argon, the operating condition temperature and the initial value at initialization to 1300K

I also get these messages at each iteration : Reversed flow on XX faces of pressure-outlet X, I don't know if this is linked with my issue

Can anyone help me understand what is happening please ?

sfawn · January 19, 2024, 08:19

Well in the end I already solved this

In the boundary conditions, I only changed the values for the mixture phase, but not for the secondary phases.
I only put a backflow volume fraction to 1 for the gas phase and it fixed my issue !

CamsDR · January 23, 2024, 12:37

Hi,
I also have a problem where I get this warning: Reversed flow on XX faces of pressure-outlet.
Do you know what it means?

sfawn · January 23, 2024, 12:41

Quote:

Originally Posted by CamsDR

Hi,
I also have a problem where I get this warning: Reversed flow on XX faces of pressure-outlet.
Do you know what it means?

Hi,

I think it means that you get a flow entering your domain from the outlet, which generates this message
From what I've quickly read online, it can slow down your convergence but is not that bad for your simulation

Maybe a bigger domain could help with this ? I haven't try sorting this as my simulation now work despite these warnings

gbert27455 · January 31, 2024, 00:49

Quote:

Originally Posted by sfawn

Well in the end I already solved this

In the boundary conditions, I only changed the values for the mixture phase, but not for the secondary phases. Donkey Kong
I only put a backflow volume fraction to 1 for the gas phase and it fixed my issue !

OHH! Glad you found a method.

January 19, 2024, 07:21	Pressure-outlet temperature problem	#1
sfawn New Member Sebastien Join Date: Nov 2021 Posts: 10 Rep Power: 5	Hello, I've got a 2d multi-phase flow with 3 phases: argon, liquid "frozen" copper and liquid "frozen" chromium (I am doing solidfication and melting simulation and at the initialization the temperature is below the melting point of both metals). The initialization is shown on the attached image, but when I run the simulation for 4 timesteps (my energy source term turns on at the 5th time step), I don't understand why I get some copper on the gas boundary, which also have a temperature of 300K (which was my initial temperature before, but I changed the material reference temperatures of copepr and argon, the operating condition temperature and the initial value at initialization to 1300K I also get these messages at each iteration : Reversed flow on XX faces of pressure-outlet X, I don't know if this is linked with my issue Can anyone help me understand what is happening please ?

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January 19, 2024, 08:19		#2
sfawn New Member Sebastien Join Date: Nov 2021 Posts: 10 Rep Power: 5	Well in the end I already solved this In the boundary conditions, I only changed the values for the mixture phase, but not for the secondary phases. I only put a backflow volume fraction to 1 for the gas phase and it fixed my issue !

January 23, 2024, 12:37		#3
CamsDR New Member Join Date: Jan 2024 Posts: 7 Rep Power: 2	Hi, I also have a problem where I get this warning: Reversed flow on XX faces of pressure-outlet. Do you know what it means?