[jakub_]

Hi there,


I've encountered a serious problem with Fluent during LES of the non-reacting jet.



Params:
Re=23 750
nozzle diam=4.6 mm
velocity profile defined at the inlet (Umax=100 m/s, Umin=3.5 m/s)
inlet perturbation - spectral synthesizer with Ti=0.1%
solver: press-vel coupling - SIMPLE, momentum - central differencing, time-integration - bounded second order implicit


I expect to get RMSE velocity at the inlet: 0.1% * 75 m/s (Umean) approx. 0.075 m/s however I get ~3 m/s!!!



I decided to turn off the inlet perturbation and I get the same RMSE value ~3 m/s!


It seems like Fluent calculates Ti using some fraction of inlet velocity apart from specified Ti value... This is completely unphysical and leads to false results for the whole class of flow problems!!! What the hell? Could someone explain it to me please?


Best regards,
Jakub