Mixing determination
 

Am looking at 2d mixing within a circular tank where a circular stirrer is offset from the centre and rotates at about 20 rad/s. A number of models for different offset values have been constructed - would it be possible to determine the level of mixing of the fluid using a plot of turbulence intensity or is there another way?

Would be grateful for assistance!

Thanks in advance

J.Spence

Re: Mixing determination
 

You can solve any passive scalar equation (e.g.,energy equation)in addition to the flow equations to study the mixing. Start with a temperature field patched in such that you have a region where its temperature is different from the remaining region, and see how the temperature field evolves with time. Or you can solve species equations instead of temperature with the flow equations. But the results would largely remain the same if turbulence is mainly responsible for mixing.

Turbulence intensity is a measure of velocity fluctuation. Relevant to mixing as it may be, it can't be interpreted as a direct measure of the degree of mixing.