[RWaluyo]

Dear all,
I am doing simulation for NH3/H2/air combustion using OpenFOAM-8 (Foundation ver.) with reactingFoam solver. There is no run time error detected, however I failed to achieve sustainable flame.

The boundary condition is based on successful experiment [1] so I don't think that specifying fuel/oxidizer composition beyond NH3/H2 flammability range is causing this ignition failure.

I also conducted similar simulation by adding NH3 on steady H2 combustion with same chemical mechanism proposed by Okafor at al. [2] The generated flame is sustainable which indicated by steady consumption of NH3. From this observation, I deduce that the problem lies on numerical side specifically mesh.

I need to get the flame ignited in my simulation so I could validate the results with experimental data. Any help would be greatly appreciated.
Attached with this message are:
1) Animation of failed ignition simulation
2) Animation of sustainable flame (different mesh)
3) Case that could be used to reproduce the failed ignition. Already tested for both series and parallel run.

NH3-TNF.zip

Failed_H2-NH3-O2.zip

sus-flame_H2-NH3-O2.zip

Regards,

Waluyo

Refereces:
[1] Tang, H., Yang, C., Wang, G., Krishna, Y., Guiberti, T. F., Roberts, W. L., & Magnotti, G. (2022). Scalar structure in turbulent non-premixed NH3/H2/N2 jet flames at elevated pressure using Raman spectroscopy. Combustion and Flame, 244.
[2] Okafor, E. C., Naito, Y., Colson, S., Ichikawa, A., Kudo, T., Hayakawa, A., & Kobayashi, H. (2018). Experimental and numerical study of the laminar burning velocity of CH4–NH3–air premixed flames. Combustion and Flame, 187, 185–198. https://doi.org/10.1016/j.combustflame.2017.09.002

[yang52079@outlook.com]

As far as I know, OpenFOAM-8 is a physical property file without NH3, is it a problem for you to write the file yourself? Please upload the NH3 file to me for a look.

[RWaluyo]

Dear Yang,

Thank you for your reply, I really appreciate it.

In OpenFOAM-8, reacting flow simulation is supported by using reactingFoam solver. I have uploaded the case (NH3-TNF.zip), which contains initial and boundary conditions of chemical species, including NH3 in 0.orig/NH3.

In case you want to check on NH3 file directly, I will attach it here:

NH3.txt

The information regarding thermophysical properties of individual species can be found in constant/foam_mech/modGRI.fmth

The information regarding chemical reactions in this simulation can be found in constant/foam_mech/modGRI.fmr

Thank you for checking my case.

Best regards,

Waluyo

Originally Posted by yang52079@outlook.com

As far as I know, OpenFOAM-8 is a physical property file without NH3, is it a problem for you to write the file yourself? Please upload the NH3 file to me for a look.

[mdhfiz]

Hi RWaluyo, did you manage to fix your issue? I am simulating the similar case and have failed to achieve a sustainable flame.