July 8, 2019 at 2:13 pm
q9999
Subscriber

 


Please:


1) axial velocity field:



 


2) axial velocity at inlet plane:



 


3) RMSE z-velocity at the inlet plane:



 


 


"Do not use spectral synthesizer." - Why?


As you can see from my post I also tried no perturbation option. What I didn't show is that I also repeated calculation for Vortex Method. All the 3 tries gave me the same result i.e., Ti at inlet ~3% of mean velocity apart from specified value 0.1%.


What I found in FLUENT manual is: "The turbulence intensity value specified at a velocity inlet for LES, as described in Section 12.20.4, is used to randomly perturb the instantaneous velocity field at the inlet. It does not specify a modeled turbulence quantity."


So, my questions are: why Ti is modelled at the inlet instead of taken explicitly? How explicitly specify Ti at the inlet in LES similarly as in case of RANS?


 


Regards,


Jakub