Interfacial length scale in mixture model
 

For air-water system, using mixture model, what's the value for the interfacial length scale? Is it the molecular diameter, for example 10^-9m?

Regards Andrew

Re: Interfacial length scale in mixture model
 

Hi Andrew, I guess that if your are using a continuous/continuous approach (ie not disperse/continuous)this is the length scale that is going to be used to mimick the surface contact area that is used to model drag for example in a diperse/continuous approach. In this case the scale is more on a "bubble diameter" sort of order.

Re: Interfacial length scale in mixture model
 

Thanks a lot. Yes I want to use continuous/continuous approach not a disperse/continuous one. Could you please give me a range for the length scale, so I can select an appropriate value to start my simulation? Normally a bubble diameter has unit of 'mm'. According to your reply, is '1cm' OK or more? Looking forward to your answer.

Regards Andrew

Re: Interfacial length scale in mixture model
 

Hi Andrew,

I think that the formula for the interfacial exchange is in the multiphase notes of the on-line CFX-5 manual (I don't have it with me, but look for the interfacila area A_alpla_beta). You will see how it mimicks the continuous/disperse approach... it might not be as simple as a bubble diameter (in terms of 'number' or value) but in effect it is related to it.