courant number

hamid1 · February 3, 2012, 05:54

how will it be interpreted if the simulation pass the criteria of courant number 0.25,
how wrong will the result of the simulation will be if the courant number is abit higher than 0.25, or if it is 1, 1.5, 2 or very high,
I am asking this because i dont have very much sense of it,
i know the definition but i dont know how much it effects the results of the simulation
Thank u so much

shk12345 · February 3, 2012, 22:50

just decrease the time step and see
decrease by 1/10 .
it will improve the results

Far · February 4, 2012, 00:41

If you dont get the required convergence then results may be inaccurate, otherwise using higher courant is recommended. This is general guideline, for your particular problem you must do the sensitivity analysis that how much convergence level is required and what is the effect of different courant no. on this convergence accuracy.

February 3, 2012, 05:54	courant number	#1
hamid1 Senior Member hamid Join Date: Nov 2010 Posts: 185 Rep Power: 15	how will it be interpreted if the simulation pass the criteria of courant number 0.25, how wrong will the result of the simulation will be if the courant number is abit higher than 0.25, or if it is 1, 1.5, 2 or very high, I am asking this because i dont have very much sense of it, i know the definition but i dont know how much it effects the results of the simulation Thank u so much

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February 3, 2012, 22:50		#2
shk12345 Senior Member shoeb khan Join Date: Nov 2011 Posts: 179 Rep Power: 14	just decrease the time step and see decrease by 1/10 . it will improve the results

February 4, 2012, 00:41		#3
Far Super Moderator Sijal Join Date: Mar 2009 Location: Islamabad Posts: 4,553 Blog Entries: 6 Rep Power: 54	If you dont get the required convergence then results may be inaccurate, otherwise using higher courant is recommended. This is general guideline, for your particular problem you must do the sensitivity analysis that how much convergence level is required and what is the effect of different courant no. on this convergence accuracy.