Mixing time problem
 

I have a problem using Fluent concerning determining mixing times (low Froude number problem). After running into serious problems I decided to do a simple test which also didn't go well..i.e.

tank (2d) with stratified flow (50-50%), on top the lighter and warm water-salt mixture and the bottom the heavy and the cold water-salt mixture. Setting the thermal conductivity to 1e-24 (so only turbulent mixing) the stratification should be stable and no mixing should occur (velocity patched zero).. however velocities in the order of 5 cm/s occur (no pattern) and the tank starts equaling out the temperature in about 1 hour where mixing times of over 100 hours with a mixer switched on were obtained in the experiments ...

Did anybody run into similar problems or has an idea where the poblem could be?

Thanks...

Re: Mixing time problem
 

Ha die Rai,

Mooi pakket he? Heb je al een fijner grid geprobeerd? En loopt die wel op 2nd order?

Groetjes Bart