engineFoam - Low temperature/no combustion

Zniacs · October 26, 2020, 09:07

Hello,

I'm running an engineFoam case using a skeletal mechanism for diesel with NOx formation (133 species and 1058 reactions) and it seems that no combustion is happening.

In order to simplify the simulation I'm using a simple cylinder, meshed in Salome, completely hexahedral and engCompRatio gives a 17.9995 return.

In one of my atempts of running a case with P1 radiation model, the max gas T @0deg was 629K. The case I'm running at this moment has a 505K max T @-3deg with no radiation model.

I have no idea why the combustion is not happening, chemistry is on and combustion is active.

Thank you in advance.

Zniacs · October 26, 2020, 14:22

Okay, I did a bit of investigating by running a aachenBomb tutorial using the chemkin files from the engineFoam case.

I figured it out that I have a problem with the liquid properties. The liquid temperature goes up a lot, while the gas temperature stays constant, which seems to me as an error in the boiling point of the liquid mixture I'm using.

I'm defining the liquid mixture in the file sprayCloudProperties as:

singlePhaseMixtureCoeffs
{
phases
(
liquid
{
C10H22 0.3;
aC11H10 0.7;
}
);
}

liquidEvaporationBoilCoeffs
{
enthalpyTransfer enthalpyDifference;
activeLiquids (C10H22 aC11H10);
}

And in the thermophysicalPorperties:

liquids
{
C10H22;
aC11H10;
}

Is this syntax correct?

October 26, 2020, 09:07	engineFoam - Low temperature/no combustion	#1
Zniacs New Member Jorge Sá Join Date: Aug 2020 Posts: 2 Rep Power: 0	Hello, I'm running an engineFoam case using a skeletal mechanism for diesel with NOx formation (133 species and 1058 reactions) and it seems that no combustion is happening. In order to simplify the simulation I'm using a simple cylinder, meshed in Salome, completely hexahedral and engCompRatio gives a 17.9995 return. In one of my atempts of running a case with P1 radiation model, the max gas T @0deg was 629K. The case I'm running at this moment has a 505K max T @-3deg with no radiation model. I have no idea why the combustion is not happening, chemistry is on and combustion is active. Thank you in advance. Last edited by Zniacs; October 28, 2020 at 09:15.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Non premixed combustion - combustion chamber pressure	Gadders	FLUENT	2	January 14, 2020 14:28
combustion in internal combustion engine	George	Main CFD Forum	0	September 7, 2006 14:41
Shell Model for Low Temperature Combustion	Phil	Main CFD Forum	0	March 17, 2006 00:34
Multicomponent fluid	Andrea	CFX	2	October 11, 2004 05:12
Combustion Convergence problems	Art Stretton	Phoenics	5	April 2, 2002 05:59

October 26, 2020, 14:22		#2
Zniacs New Member Jorge Sá Join Date: Aug 2020 Posts: 2 Rep Power: 0	Okay, I did a bit of investigating by running a aachenBomb tutorial using the chemkin files from the engineFoam case. I figured it out that I have a problem with the liquid properties. The liquid temperature goes up a lot, while the gas temperature stays constant, which seems to me as an error in the boiling point of the liquid mixture I'm using. I'm defining the liquid mixture in the file sprayCloudProperties as: singlePhaseMixtureCoeffs { phases ( liquid { C10H22 0.3; aC11H10 0.7; } ); } liquidEvaporationBoilCoeffs { enthalpyTransfer enthalpyDifference; activeLiquids (C10H22 aC11H10); } And in the thermophysicalPorperties: liquids { C10H22; aC11H10; } Is this syntax correct?