Using reactingFoam from SandiaD template for H2 O2 non premixed combustion

MateusLatt · April 7, 2018, 13:14

Hello everyone,

I am trying to simulate a H2-02 combustion using some modifications in the SadiaD template. After exporting a geometry of a liquid rocket combustion chamber and meshing it (using blockMesh followed by snappyhexmesh). I was able to obtain the H2 and O2 flow and a simple mixing of the species.After 50 interactions of the program I have programmed the chemistry "on" in the constant folder, but no chemical reaction or changing in the temperature occurred.
I read in this forum that the combustion was supposed to be ignited using the setFieldsDict, i understood that there was a "box" with the boundaries conditions that starts the flame. But I am not able to set the position of this box in my geometry to initiate the combustion. Does anyone ever had a similar problem?Or i should study more materials to understand better this simulation, and if I do, does anyone could send it to me?

Regards,

Mateus

Dano62 · April 9, 2018, 17:53

The box defines the domain of any special regions. I would assume that you would specify a very high temperature within this box to initiate combustion. You should be able set the temperature similar to this, then run setFields. https://github.com/OpenFOAM/OpenFOAM.../setFieldsDict

MateusLatt · April 22, 2018, 21:57

Thanks for your answer. I am trying to set this box inside my combustion chamber. But how can i set the box position using those inputs:
"
box ( 0.04 0.04 -1.0 ) ( 0.06 0.06 1.0 );

"

Because I've modeled a .STL combustion chamber in Blender and used SnappyHexMesh to mesh it. I was trying to run set Fields and to locate the Box position using ParaFoam right after running setFields. Is there a more efficient way?

MateusLatt · April 23, 2018, 00:24

Ok, I did it. I did some small changes to setFieldsDict box while paraFoam was opened and i could set the box to the position that i needed by running SetFields multiple times.

It was like

(xi,yi,zi) (xf,yf,zf), where xi= x initial
where xf= x final

And xf-xi is the x dimension of a box in the x axis.The same for the other directions.

Other problem was that I had fixed the temperature of the wall, so the box could't change the temperature of the combustion chamber, the solution was to set: type zerogradient.

April 7, 2018, 13:14	Using reactingFoam from SandiaD template for H2 O2 non premixed combustion	#1
MateusLatt New Member Mateus Grassano Lattari Join Date: Apr 2018 Posts: 16 Rep Power: 8	Hello everyone, I am trying to simulate a H2-02 combustion using some modifications in the SadiaD template. After exporting a geometry of a liquid rocket combustion chamber and meshing it (using blockMesh followed by snappyhexmesh). I was able to obtain the H2 and O2 flow and a simple mixing of the species.After 50 interactions of the program I have programmed the chemistry "on" in the constant folder, but no chemical reaction or changing in the temperature occurred. I read in this forum that the combustion was supposed to be ignited using the setFieldsDict, i understood that there was a "box" with the boundaries conditions that starts the flame. But I am not able to set the position of this box in my geometry to initiate the combustion. Does anyone ever had a similar problem?Or i should study more materials to understand better this simulation, and if I do, does anyone could send it to me? Regards, Mateus

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April 9, 2018, 17:53		#2
Dano62 New Member Daniel Norton Join Date: Feb 2015 Posts: 17 Rep Power: 11	The box defines the domain of any special regions. I would assume that you would specify a very high temperature within this box to initiate combustion. You should be able set the temperature similar to this, then run setFields. https://github.com/OpenFOAM/OpenFOAM.../setFieldsDict

April 22, 2018, 21:57		#3
MateusLatt New Member Mateus Grassano Lattari Join Date: Apr 2018 Posts: 16 Rep Power: 8	Thanks for your answer. I am trying to set this box inside my combustion chamber. But how can i set the box position using those inputs: " box ( 0.04 0.04 -1.0 ) ( 0.06 0.06 1.0 ); " Because I've modeled a .STL combustion chamber in Blender and used SnappyHexMesh to mesh it. I was trying to run set Fields and to locate the Box position using ParaFoam right after running setFields. Is there a more efficient way?

April 23, 2018, 00:24		#4
MateusLatt New Member Mateus Grassano Lattari Join Date: Apr 2018 Posts: 16 Rep Power: 8	Ok, I did it. I did some small changes to setFieldsDict box while paraFoam was opened and i could set the box to the position that i needed by running SetFields multiple times. It was like (xi,yi,zi) (xf,yf,zf), where xi= x initial where xf= x final And xf-xi is the x dimension of a box in the x axis.The same for the other directions. Other problem was that I had fixed the temperature of the wall, so the box could't change the temperature of the combustion chamber, the solution was to set: type zerogradient.