[topperz]

Hi...
First of all thanks for the forum.

I'm simulating Hydrogen fueled engine using G-eqn model.
To calculate laminar flame speed I'm using Gulder equation but I don't know the gulder co-efficients 'omega', 'eta' and 'zeta' for Hydrogen.

Can anyone provide the same or any alternate method to get the laminar flame speeds ?

Thanks in advance!

[xieshengbai]

Hi,

Currently we don't have those parameters as default for Hydrogen. You may find relevant researches else where. For example, this one:

Milton, B.E., Keck, J.C. (1984) Laminar burning velocities in stoichiometric hydrogen and hydrogen-hydrocarbon gas mixtures, Combustion and Flame, Volume 58, Issue 1, 13-22

You would have to make a custom UDF for the hydrogen parameters as the paper's equations are different from Metghalchi & Keck and Gulder.

Hope it helps.

[JonathanJohnsplass]

Hi. I computed the Gulder coefficients for hydrogen and other gas compounds and multicompositions in my master thesis. I developed a python script where i scripted an optimization routine based on the open-source chemical kinetics software Cantera.

I computed the Gulder coefficients for hydrogen with the GRI-Mech 3.0. Here follows the coefficients for hydrogen:


W [m/s] = 2.094
η [-] = 1.068
ξ [-] = 0.424
R**2 (W,ηξ) [-] = 0.97
Φ [-] = [0.3-2.5]
α [-] = 2.9
R**2 (α) [-] =0.99
T [-] = [250 K -961 K]
β [-] = -0.04
R**2 (β) [-] =0.78
P [-] = [0.5 atm - 10 atm]

*R**2 = Coefficient of determination
*I attached the python files inside a zip-file.

[Tobi]

Hi Jonathan,



is there more information about your scripts available? I opened it but as there is no documentation it is a bit tricky to understand for someone who is not as familiar as you with the stuff.

Tobi

[JonathanJohnsplass]

Dear Tobias

The aim of the scripts is to estimate the Gulder coefficients by approximating the laminar burning velocity as a function of pressure, temperature and fuel-air ratio, and then fitting the Gulder coefficients to the approximated data points.
The laminar burning velocity estimate in the provided scripts is based on the class FREEFLAME [1] in Cantera.

“Cantera is an open-source suite of object-oriented software tools for problems involving chemical kinetics, thermodynamics, and/or transport processes. The software automates the chemical kinetic, thermodynamic, and transport calculations so that the users can efficiently incorporate detailed chemical thermo-kinetics and transport models into their calculations.” [2]

The alpha parameter is fitted to the data series where the laminar burning velocity is a function of temperature, the beta coefficient is fitted to pressure, and Omega, Eta and Xi is fitted when the laminar burning velocity is a function of equivalence ratio (normalized fuel-air ratio).

It is necessary to find a chemical kinetic mechanism which contains the combustion species you want to simulate. Most of these mechanisms is in Chemkin-format [3]. It is necessary to convert the files in Chemkin format into the Cantera format CTI. Use the method describe in [4].

The CRECK Modeling Group have several detailed kinetic mechanisms which is Open-source [5], Cerfacs – the Centre of basic and applied research specialized in modelling and numerical simulation also provides kinetic mechanisms [6].

I suggest that you should check out the examples provided in Cantera [7]. You can pm me if you have a certain case you want to simulate.

I used this method to generate the results in the paper [8], and the necessary parameters to simulate dimethyl carbonate with XiFOAM in [9].

Reference:

[1] https://cantera.org/documentation/do...html#freeflame
[2] Goodwin, D. G., Moffat, H. K., & Speth, R. L. (2009). Cantera: An object-oriented software toolkit for chemical kinetics, thermodynamics, and transport processes. Caltech, Pasadena, CA.
[3] Kee, R. J., Rupley, F. M., & Miller, J. A. (1989). Chemkin-II: A Fortran chemical kinetics package for the analysis of gas-phase chemical kinetics (No. SAND-89-8009). Sandia National Labs., Livermore, CA (USA).
[4] https://cantera.org/tutorials/ck2cti-tutorial.html
[5] http://creckmodeling.chem.polimi.it/...led-mechanisms
[6] http://www.cerfacs.fr/cantera/
[7] https://cantera.org/examples/python/...example-onedim
[8] Johnsplass, J., Henriksen, M., Vågsæther, K., Lundberg, J., & Bjerketvedt, D. (2017, September). Simulation of burning velocities in gases vented from thermal run-a-way lithium ion batteries. In Proceedings of the 58th Conference on Simulation and Modelling (SIMS 58) Reykjavik, Iceland, September 25th–27th, 2017 (No. 138, pp. 157-161). Linköping University Electronic Press.
[9] Johnsplass, J. (2017). Li-ion battery safety (Master's thesis, Høgskolen i Sørøst-Norge).

[Manideep304]

Originally Posted by JonathanJohnsplass

Hi. I computed the Gulder coefficients for hydrogen and other gas compounds and multicompositions in my master thesis. I developed a python script where i scripted an optimization routine based on the open-source chemical kinetics software Cantera.

I computed the Gulder coefficients for hydrogen with the GRI-Mech 3.0. Here follows the coefficients for hydrogen:


W [m/s] = 2.094
η [-] = 1.068
ξ [-] = 0.424
R**2 (W,ηξ) [-] = 0.97
Φ [-] = [0.3-2.5]
α [-] = 2.9
R**2 (α) [-] =0.99
T [-] = [250 K -961 K]
β [-] = -0.04
R**2 (β) [-] =0.78
P [-] = [0.5 atm - 10 atm]

*R**2 = Coefficient of determination
*I attached the python files inside a zip-file.

Hi, I am working with XiFoam solver for hydrogen/air mixture. Thank you for the gulders coefficients. Could you please send me the link to your masters thesis document where you have calculated these gulders coefficients so that I could use it as a reference in my thesis. Thank you in advance.

[Matteoccc]

Originally Posted by JonathanJohnsplass

Hi. I computed the Gulder coefficients for hydrogen and other gas compounds and multicompositions in my master thesis. I developed a python script where i scripted an optimization routine based on the open-source chemical kinetics software Cantera.

I computed the Gulder coefficients for hydrogen with the GRI-Mech 3.0. Here follows the coefficients for hydrogen:


W [m/s] = 2.094
η [-] = 1.068
ξ [-] = 0.424
R**2 (W,ηξ) [-] = 0.97
Φ [-] = [0.3-2.5]
α [-] = 2.9
R**2 (α) [-] =0.99
T [-] = [250 K -961 K]
β [-] = -0.04
R**2 (β) [-] =0.78
P [-] = [0.5 atm - 10 atm]

*R**2 = Coefficient of determination
*I attached the python files inside a zip-file.

Hi, I am a new member of this community and I am a principiant in the use of CFD software. I need the Gulder coeffiecients for methanol, can you help me?

[SamWijey]

CONVERGE allows you to read laminar flame speeds from a tabulated table. This will eliminate the need for any correlations. As long as you have a chemical mechanism for the fuel of interest, then we can use CONVERGE 1D solver to generate this table and use in your 3D simulation.