CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   CFX (http://www.cfd-online.com/Forums/cfx/)
-   -   Interfacial length scale in mixture model (http://www.cfd-online.com/Forums/cfx/19394-interfacial-length-scale-mixture-model.html)

Andrew December 26, 2002 12:42

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

Holidays December 27, 2002 12:29

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.

Andrew December 27, 2002 21:19

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

Holidays December 30, 2002 09:38

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.


All times are GMT -4. The time now is 10:45.