volume fractions in homogeneous flow model?

August 25, 2007, 07:15

Hi, I have a question about the behaviour of the homogeneous flow model when used to model diffusive mixing of two very similar fluids. Does anybody know whether the volume fractions are calculated from the solution of the flow field or if there is an extra equation? (If there is an extra eqn. how is it implemented?) Was looking for that in CFX help but couldn't find an answer. Any help is most apreciated!

[The problem I'm working on is the mixing behaviour of two fluids in a closed channel. All dimensions are very small (channel is 250 by 500 micron), and reynolds numbers are between 0.3 and 33.0. The two fluids are slightly different in density and viscosity but the difference is within 5%.]

August 26, 2007, 19:42

Hi,

Mass or volume fraction is an additional equation to solve. The equation is discussed in the theory manual.

Glenn Horrocks

August 25, 2007, 07:15	volume fractions in homogeneous flow model?	#1
Matthias Rohner Guest Posts: n/a	Hi, I have a question about the behaviour of the homogeneous flow model when used to model diffusive mixing of two very similar fluids. Does anybody know whether the volume fractions are calculated from the solution of the flow field or if there is an extra equation? (If there is an extra eqn. how is it implemented?) Was looking for that in CFX help but couldn't find an answer. Any help is most apreciated! [The problem I'm working on is the mixing behaviour of two fluids in a closed channel. All dimensions are very small (channel is 250 by 500 micron), and reynolds numbers are between 0.3 and 33.0. The two fluids are slightly different in density and viscosity but the difference is within 5%.]

August 26, 2007, 19:42	Re: volume fractions in homogeneous flow model?	#2
Glenn Horrocks Guest Posts: n/a	Hi, Mass or volume fraction is an additional equation to solve. The equation is discussed in the theory manual. Glenn Horrocks

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