Hi, 

I have a question on turbulence.

Turbulence causes the formation of eddies of many different length scales. Most of the kinetic energy of the turbulent motion is contained in the large-scale structures. The energy "cascades" from these large-scale structures to smaller scale structures by an inertial and essentially inviscid mechanism. This process continues, creating smaller and smaller structures which produces a hierarchy of eddies. Eventually this process creates structures that are small enough that molecular diffusion becomes important and viscous dissipation of energy finally takes place. 

Now if i consider a case where a stirrer is rotating with certain speed. Liquid will be having a big vortex and some small vortices.  Now if the stirrer speed remains same, bigger vortices will always remain in the same size and it will never form smaller vortices. Then how the energy transformation takes place? Whatever smaller vortices are there in the medium, they are not due to the breakage of big eddies, they are formed due to turbulent medium. And the energy is transferred from the bigger eddies to smaller ones due to shearing action?

Existance of smaller eddies does not depend on the bigger eddies and they are not formed from the breakage of bigger eddies?

I know my perception may be wrong, but where is the mistakes?

Please someone answer.

Thanks,

Vivek

More Vivek Arora's questions See All
Similar questions and discussions