dt and smaller time step

zxj160 · May 30, 2013, 10:28

Dear Foamers,

I am wondering how to use dt for some variables and another time steps smaller than dt for other variables.
Specifically,
dt :0.02 for V1......
and another dt (0.01, 20 increments of dt specified in the control) for other V2......

My best regards,
Jian

akidess · May 31, 2013, 04:20

Have a look at interFoam: Here we have an extra loop for subcycling of alpha, which means alpha will be solved with a fraction of the regular time step if activated.

zxj160 · May 31, 2013, 10:25

Many thanks. But I am wondering how to activate the subcycling of total deltaT. Where can I find the 'pimple.dict()' and the corresponding tutorial case?
....
In the alphaEqnSubCycle.H,

label nAlphaCorr(readLabel(pimple.dict().lookup("nAlphaC orr")));

label nAlphaSubCycles(readLabel(pimple.dict().lookup("nA lphaSubCycles")));

May 30, 2013, 10:28	dt and smaller time step	#1
zxj160 Senior Member Jian Zhong Join Date: Feb 2012 Location: Birmingham Posts: 109 Rep Power: 14	Dear Foamers, I am wondering how to use dt for some variables and another time steps smaller than dt for other variables. Specifically, dt :0.02 for V1...... and another dt (0.01, 20 increments of dt specified in the control) for other V2...... My best regards, Jian

May 31, 2013, 04:20		#2
akidess Senior Member Anton Kidess Join Date: May 2009 Location: Germany Posts: 1,377 Rep Power: 30	Have a look at interFoam: Here we have an extra loop for subcycling of alpha, which means alpha will be solved with a fraction of the regular time step if activated. zxj160 likes this. __________________ On twitter @akidTwit Spend as much time formulating your questions as you expect people to spend on their answer.

May 31, 2013, 10:25		#3
zxj160 Senior Member Jian Zhong Join Date: Feb 2012 Location: Birmingham Posts: 109 Rep Power: 14	Many thanks. But I am wondering how to activate the subcycling of total deltaT. Where can I find the 'pimple.dict()' and the corresponding tutorial case? .... In the alphaEqnSubCycle.H, label nAlphaCorr(readLabel(pimple.dict().lookup("nAlphaC orr"))); label nAlphaSubCycles(readLabel(pimple.dict().lookup("nA lphaSubCycles")));