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arash_aifoil April 5, 2010 04:43

turbulence
 
Hi,
I have a question about turbulence.
Do any one have info on the variations of turbulent kinetic energy(k) and dissipation rate(epsilon) before and after an obstruction ( like a bridge bracket at water)?

Regards,
Arash

Hamidzoka April 5, 2010 08:23

dear arash
when flow is faced with an obstacle such that disturbances increase, turbulent energy will be increased. tuebulent energy in fact is a fraction of total energy of fluid flow which concerns with flow disturbances.
in the other hand dissipation rate variations is proportional to turbulent energy. once the turbulent energy increases, dissipation rate is also increases. in other words, turbulent kinetic energyis a fraction of total flow energy that is transfered from mean flow to large scales (eddies) of turbulent flow and consequently it is going to be dissipated in small scales (eddies) as "epsilon". so they are completely tied up together.

regards


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