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-   -   simulate nanofluids with mixture model (https://www.cfd-online.com/Forums/fluent/249221-simulate-nanofluids-mixture-model.html)

rasoul1375 April 27, 2023 04:44

simulate nanofluids with mixture model
 
hello. I want to simulate cuo nanoparticles dispersed in 60:40 Eg/W base fluid with mixture model. I defined 2 fluid materials for base fluid and cuo nanoparticles but I don't know what value to set for viscosity of cuo! Should I set it to zero?
and also should I activate the granular option for it? I tried both ways, but after running, the viscosity of the mixture is wrong and it is almost equal to the viscosity of the base fluid. what should I do?

NickFL April 27, 2023 05:15

The nanoparticles are dispersed in the water/ethylene glycol mixture. The solid particles themselves do not have viscosity perse. The liquid mixture will of course. Generally nanoscale size particles will follow the flow very well unless acted upon by an outside source. If you are setting your model up with Copper Oxide nanoparticles as a component in a mixture, leave it to what your use for the liquid mixture.



What is the particle loading in your model? How are you attempting to model the particles? Will you be using the Population Balance models? What are you attempting to see in the results? All of these really go to answering the question.

rasoul1375 April 27, 2023 05:41

Quote:

Originally Posted by NickFL (Post 848876)
The nanoparticles are dispersed in the water/ethylene glycol mixture. The solid particles themselves do not have viscosity perse. The liquid mixture will of course. Generally nanoscale size particles will follow the flow very well unless acted upon by an outside source. If you are setting your model up with Copper Oxide nanoparticles as a component in a mixture, leave it to what your use for the liquid mixture.



What is the particle loading in your model? How are you attempting to model the particles? Will you be using the Population Balance models? What are you attempting to see in the results? All of these really go to answering the question.

I am simulating an article about the use of nanofluids inside the car radiator. I use the two-phase mixture model and I have set the Population balance model to off (of course, I am not familiar with it and I don't know if it should be on or off), I considered the inlet velocity for the base fluid and nanoparticles to be equal, and the Reynolds at the inlet is almost equal to 200 and I used the outlet pressure boundary condition for the outlet. I considered the convection boundary condition on the walls. I am looking for changes in Cf and h in the results. When I set the viscosity of cuo to zero, the viscosity of the mixture after running is different from the number reported by the article (of course, the article solved it in a single phase, but I want to reach the results from the two-phase mixture model)
What are your recommendations for simulating nanoparticles in the mixture method?

NickFL April 27, 2023 12:15

Do you know how the changes in viscosity and heat conductivity will change as a function of particle loading? For what you mention, I do not see any reason to explicitly model the particles. It would simply be different simulations with different material properties based upon the amount of CuO in the stream. Is there a reason why you need to include the particles?


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