Can a chamber be "pre-filled" with another fluid?

Khadorna · September 20, 2021, 07:06

Hello !

I've been trying to search information about this issue, but I have not been able to find an answer. It is a simple question, is it possible to have a chamber pre-filled with a fluid (air in this case) and then inject another one into it, with the air already in the chamber? I want to see how a flame expands in a combustion chamber, and when having velocity inlets to get the species in, the flow for the fuel is altered.

Thank you in advance for your insights

LuckyTran · September 20, 2021, 09:45

Yes. You just set up the proper initial conditions. The details changes a little bit depending on what is your combustion model but it still comes down to initialization.

It's actually harder to do a simulation where the chamber is empty.

Khadorna · September 20, 2021, 13:51

Quote:

Originally Posted by LuckyTran

Yes. You just set up the proper initial conditions. The details changes a little bit depending on what is your combustion model but it still comes down to initialization.

It's actually harder to do a simulation where the chamber is empty.

Thank you!

And how could it be done? By patching the species inside the chamber?

Sorry for the novice questions, but thank you so much for your time.

LuckyTran · September 20, 2021, 15:27

You just specify it as initial conditions.

It can be done with patching as well but patching is a tool for overwriting fields after-the-fact. You don't need to patch if you just do it correctly the first time.

To be more specific, you need to at some point specify the mass fractions of individual species or fuel/oxidizer depending on your species transport model and/or combustion model.

September 20, 2021, 07:06	Can a chamber be "pre-filled" with another fluid?	#1
Khadorna New Member Join Date: Aug 2021 Posts: 8 Rep Power: 5	Hello ! I've been trying to search information about this issue, but I have not been able to find an answer. It is a simple question, is it possible to have a chamber pre-filled with a fluid (air in this case) and then inject another one into it, with the air already in the chamber? I want to see how a flame expands in a combustion chamber, and when having velocity inlets to get the species in, the flow for the fuel is altered. Thank you in advance for your insights

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September 20, 2021, 09:45		#2
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,751 Rep Power: 66	Yes. You just set up the proper initial conditions. The details changes a little bit depending on what is your combustion model but it still comes down to initialization. It's actually harder to do a simulation where the chamber is empty.

September 20, 2021, 15:27		#4
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,751 Rep Power: 66	You just specify it as initial conditions. It can be done with patching as well but patching is a tool for overwriting fields after-the-fact. You don't need to patch if you just do it correctly the first time. To be more specific, you need to at some point specify the mass fractions of individual species or fuel/oxidizer depending on your species transport model and/or combustion model.