Learning Forum

[mdfaizan444]

hi to all, i am doing nanofluid simulation with mixture model in which bafe fluid(water) as well as nanofluid properties changes with temperature. My query is..

1) In mixture model only fluid is considered neglecting particle (particle act as a fluid with differet phase)?

2) how i incorporate both base fluid as well as nano fluid properties as it changes with temperature 

[Rob]

You've got two viscosity profiles there: which one do you want to use?  I'm also concerned that the exponents on the curves are very small, and don't have many significant figures: please plot these in Excel (or similar) over the range you need and post the graphs (inline images). 

Depending on whether the nanofluid particles are expected to separate you can add them as a separate phase (mixture model) or just adjust the carrier phase properties to include the extra material (single phase). 

[mdfaizan444]

Actually i am validating one of the paper in which they have used mixture model for nanofluid transport.

i am using water as a base fluid and Al2O3 as nanoparticle. in mixture model primary phase i am giving water and what will be my secondary phase?, as in secondary phase option only liquid material is showing in the option. 

Also in mixture model do i need to calculate drift velocity, slip velocity mean viscosity or ANSYS take it by default?, As in ANSYS guide manual these formula's are given.

 

[Rob]

Secondary phase will be granular, but the material is a fluid type not a solid. Solids are for walls etc. 

Given the size of the particles they should follow the flow exactly, so you won't need drift. If you're expecting sedimentation use the Eulerian model. 

[mdfaizan444]

Ni i dont expet sedimentation, in mixture model, in phase 2, what will be mine phase material and if i considered granular what i will have to put in granular viscosity?

Also i need to specify the AL2O3 properties like density, thermal conductivity specific heat etc. where i have to put it? 

Do i need to calculate average properties of nano fluid, if yes where i have to put it? Or these equations is for homogeneous model?

also where i have specify volume fraction of solid particle?

[Rob]

Add another fluid species with the Al2O3 properties, and read the documentation for the settings (click Help on the phase panel). 

Re single v two phase properties: you need to decide whether you need the granular phase or whether you can adjust the water properties to mimic it's presence. 

 

As an aside: please don't open two threads on the same topic.    /forum/forums/topic/problem-with-2-phase-flow-in-fluent/

I'll lock this topic, so please repost anything necessary in there.