MULTIPHASE - FREE SURFACE & MIXTURE MODEL

November 17, 2004, 11:21

I try to model the flow into stratified sea. The cause for the stratification is the difference of the salinity. As I know, in Fluent I can't use the salinity as a parameter and calculate the density as a function of the salinity (and secondary of the temperature). So, I have thought to use the multiphase mixture model with two phases of liquid, (for example one with density 1010 and one with density 1025 kg/m3) and choose as initial condition the fraction of the two phases as a function of the depth.

On the other hand, the model requires free surface, so I need to use air as an additional phase including the VOF model. The conflict is that I can't use the VOF model and the mixture model simultaneously.

Any idea?

November 18, 2004, 10:50

You could try to use a UDS to describe the concentration of salt in the water. Then you can calculate the density of water depending on the value of the UDS in each cell by means of a simple UDF.

This way you don't have to use the mixture model, and you can use the VOF model for your water-air surface.

November 19, 2004, 05:01

This is exactly what I need. Thanks a lot.

anissa · April 28, 2009, 12:46

i want to know exactly how to enter the salinity

November 17, 2004, 11:21	MULTIPHASE - FREE SURFACE & MIXTURE MODEL	#1
Aris Guest Posts: n/a	I try to model the flow into stratified sea. The cause for the stratification is the difference of the salinity. As I know, in Fluent I can't use the salinity as a parameter and calculate the density as a function of the salinity (and secondary of the temperature). So, I have thought to use the multiphase mixture model with two phases of liquid, (for example one with density 1010 and one with density 1025 kg/m3) and choose as initial condition the fraction of the two phases as a function of the depth. On the other hand, the model requires free surface, so I need to use air as an additional phase including the VOF model. The conflict is that I can't use the VOF model and the mixture model simultaneously. Any idea?

November 18, 2004, 10:50	Re: MULTIPHASE - FREE SURFACE & MIXTURE MODEL	#2
Tanja Guest Posts: n/a	You could try to use a UDS to describe the concentration of salt in the water. Then you can calculate the density of water depending on the value of the UDS in each cell by means of a simple UDF. This way you don't have to use the mixture model, and you can use the VOF model for your water-air surface.

November 19, 2004, 05:01	Re: MULTIPHASE - FREE SURFACE & MIXTURE MODEL	#3
Aris Guest Posts: n/a	This is exactly what I need. Thanks a lot.

April 28, 2009, 12:46	salinity	#4
anissa New Member anissa ghomrassi Join Date: Apr 2009 Posts: 5 Rep Power: 17	i want to know exactly how to enter the salinity

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