Too high values of temperature, pressure and velocity

valahian1 · January 22, 2015, 12:03

Hello to all of you!
I try to model (in FLUENT 15.0.0) an explosion of air-methane stoichiometric composition in a pipe with a closed end. I used Composition PDF Transport, Eulerian, Chemkin databasis and spark ignition. The mixture ignites well and burns, but it reaches very high temperatures (5000K - the limit imposed by program), pressures (about 2100000Pa) and velocities (greater than 3000m/s). I modified up and down the values in Arrhenius equation of Chemkin mechanism, but I obtained same results.
Have you any idea how to reduce those values?
Thank you!

hazwani fatihah · July 1, 2015, 04:53

hi nick,

Did you get the solution?I have a same problem. I intend to simulate gas explosion behavior involving premixed methane/air mixture in a closed straight pipe...i really have no idea how to set the concentration (fuel/air mixture) inside the closed pipe prior ignition as the pipe contains no inlet or outlet BC..... ..also I am not sure how to simulate ignition initiation inside the pipe..

Do you have any idea on this problem?

Thanks

January 22, 2015, 12:03	Too high values of temperature, pressure and velocity	#1
valahian1 Member Nick Join Date: Feb 2012 Posts: 33 Rep Power: 14	Hello to all of you! I try to model (in FLUENT 15.0.0) an explosion of air-methane stoichiometric composition in a pipe with a closed end. I used Composition PDF Transport, Eulerian, Chemkin databasis and spark ignition. The mixture ignites well and burns, but it reaches very high temperatures (5000K - the limit imposed by program), pressures (about 2100000Pa) and velocities (greater than 3000m/s). I modified up and down the values in Arrhenius equation of Chemkin mechanism, but I obtained same results. Have you any idea how to reduce those values? Thank you!

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July 1, 2015, 04:53		#2
hazwani fatihah New Member hazwani Join Date: Nov 2014 Posts: 15 Rep Power: 12	hi nick, Did you get the solution?I have a same problem. I intend to simulate gas explosion behavior involving premixed methane/air mixture in a closed straight pipe...i really have no idea how to set the concentration (fuel/air mixture) inside the closed pipe prior ignition as the pipe contains no inlet or outlet BC..... ..also I am not sure how to simulate ignition initiation inside the pipe.. Do you have any idea on this problem? Thanks