Time Step in LES
 

Hi Every one.
i want to solve a turbulent model in fluent with LES. as you know LES is a transient model. my problem is that i dont know how much my time step should be.:confused::confused::confused::confused:
is there any body help me?
tnx.

hi,
generally speaking, the time step in les is the reciprocal of Re number.
i.e. if the Re number is 2000, the time step should be no more than 0.0005.

Time step is LES for Re=10^5
 

Thank you. dear davedong.
wow what a small time step! my problem Re is 10^5. do you know how much my time step should be? or generelly is there any releation between Re and best time step?:confused:

Best Regards.

hi,
as i know, it's a rule in Smagorisky model. the reciprocal of Re is equal to the small spacial scale divided by the velocity, in another word, the time step size.
10e-5 time step size is OK. it is absolutely right.
my native language is not english. may it will not make you misunderstand.