[sima_udf]

Hi,

I want to use mixture model for nanofluids in fluent but I want to change the the fluent defined viscosity and thermal conductivity of mixture. I want to use another formula for these properties.
How can I do this?

Thanks.

[Amir]

Originally Posted by sima_udf

Hi,

I want to use mixture model for nanofluids in fluent but I want to change the the fluent defined viscosity and thermal conductivity of mixture. I want to use another formula for these properties.
How can I do this?

Thanks.

Dear Sima,

I also did some investigations in nano-fluids field; as I know, multi-phase modelling in not proper for this purpose! you can easily use scalar transport equation. In order to define new variables, you can write simple UDFs which define these properties as functions of volume fraction.

Bests,

[abhilasht]

Originally Posted by sima_udf

Hi,

I want to use mixture model for nanofluids in fluent but I want to change the the fluent defined viscosity and thermal conductivity of mixture. I want to use another formula for these properties.
How can I do this?

Thanks.

I`m facing problems in mixture model for the same simulation. Did you complete the simulation? Kindly help me. Tell me the steps. How to assign phase velocity using mixture velocity data.

[vinerm]

If you want to modify properties and you want to use some formulation that is unavailable in Fluent, then you just need to write UDF. Property UDFs are usually simple. Look at the example at

https://www.afs.enea.it/project/nept...udf/node46.htm

[abhilasht]

Originally Posted by vinerm

If you want to modify properties and you want to use some formulation that is unavailable in Fluent, then you just need to write UDF. Property UDFs are usually simple. Look at the example at

https://www.afs.enea.it/project/nept...udf/node46.htm

Dear Sir,


I`m having mixture velocity and for velocity inlet boundary condition, it is asked to provide velocity of different phase. How can I get phase velocities using mixture velocity data. Kindly help me.

[vinerm]

If you have no information of different phase velocities at the inlet, then you can apply same for both. You can certainly determine if there could be a significant difference in their velocities or not. If the inlet of you domain is located at such a location that the fluid has traveled a rather long distance before it, then you can safely assume that both phases would have similar velocity. Otherwise, you can estimate a value using either drift flux models or slip models. However, you need to know the regime of the flow for that since there are always some coefficients in these models that require knowledge of the flow regime, such as, bubbly or not.