caracteristic turbulence time in LES
 

Hi all, My points of interest in CFD are chemical engineering applications (specially turbulent reacting flows and turbulent precipitation/crystallization). In those fields, the caracteristic time of turbulence is of importance for it has to be compared with the chemical reaction time. In my former runs with RANSE, I was used to use the ratio k/epsilon as the caracteristic turbulence time. But what about in LES calculations ? As I'm pretty new in LES, can anyone can give me some advices ? THX