Time step problem

Prateek garg · December 24, 2012, 03:14

Hi all,

I ran a simulation with for mixing of Jet A vapor and air successfully with time step size of .001 sec for 1 sec. now, i wan to used these results for simulating combustion in new def file I am specifying time step size 1e-06 and total time .001 but everytime It runs only 1 timestep and says run completed normally as simulation time reached. when i gave total time duration of 1 sec and time step size of 1e-06 it runs for 10 timesteps and says the same thing i.e. that simulatiom time reached. in both the cases I am taking initial time 0 sec. does it takes the timestep size from the previous simulation??
Where is the mistake I dont know please help?

cdegroot · December 24, 2012, 04:50

I am assuming you are continuing your previous run by using Initial Values Specification in Solver manager. If you select "continue history from" then it will continue the time from the previous case. Otherwise time starts back at zero.

Elio · December 24, 2012, 04:58

Hello guys,
i know this might seem quite dumb, but i do not know how to post a new question on this forum. Any help?
Most appreciated

energy382 · December 24, 2012, 09:19

just click on "new thread" (the button top left, below CFX). but please choose the right forum for your request.

regards,
christoph

Prateek garg · December 24, 2012, 09:21

@CDEGROOT Thank you very much. It was a great help.

December 24, 2012, 03:14	Time step problem	#1
Prateek garg Member Prateek Join Date: Mar 2012 Location: Bangalore Posts: 32 Rep Power: 14	Hi all, I ran a simulation with for mixing of Jet A vapor and air successfully with time step size of .001 sec for 1 sec. now, i wan to used these results for simulating combustion in new def file I am specifying time step size 1e-06 and total time .001 but everytime It runs only 1 timestep and says run completed normally as simulation time reached. when i gave total time duration of 1 sec and time step size of 1e-06 it runs for 10 timesteps and says the same thing i.e. that simulatiom time reached. in both the cases I am taking initial time 0 sec. does it takes the timestep size from the previous simulation?? Where is the mistake I dont know please help?

December 24, 2012, 09:21	Time step Problem	#5
Prateek garg Member Prateek Join Date: Mar 2012 Location: Bangalore Posts: 32 Rep Power: 14	@CDEGROOT Thank you very much. It was a great help.

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December 24, 2012, 04:50		#2
cdegroot Senior Member Chris DeGroot Join Date: Nov 2011 Location: Canada Posts: 414 Rep Power: 17	I am assuming you are continuing your previous run by using Initial Values Specification in Solver manager. If you select "continue history from" then it will continue the time from the previous case. Otherwise time starts back at zero.

December 24, 2012, 04:58		#3
Elio New Member Join Date: Dec 2012 Posts: 12 Rep Power: 13	Hello guys, i know this might seem quite dumb, but i do not know how to post a new question on this forum. Any help? Most appreciated

December 24, 2012, 09:19		#4
energy382 Senior Member Christoph Join Date: May 2011 Location: Germany Posts: 182 Rep Power: 17	just click on "new thread" (the button top left, below CFX). but please choose the right forum for your request. regards, christoph