CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > FLUENT

Nanofluid simulation

Register Blogs Members List Search Today's Posts Mark Forums Read

Like Tree5Likes
  • 1 Post By engrmansoor2534
  • 1 Post By engrmansoor2534
  • 2 Post By engrmansoor2534
  • 1 Post By engrmansoor2534

Reply
 
LinkBack Thread Tools Display Modes
Old   November 23, 2014, 09:49
Default Nanofluid simulation
  #1
Member
 
Mansoor Ahmed
Join Date: Apr 2014
Location: Pakistan
Posts: 44
Rep Power: 3
engrmansoor2534 is on a distinguished road
Nanofluid simulation using ansys fluent

Hi everyone
I m simulating nanofluids as single phase. I have updated the entire properties of fluid with that of nanofluid. But I don't know how to enter nanoparticle size as I want to simulate the offect of nano particle size on heat transfer capability and pressure drop characteristics.kindly help me in this regard
haidernuceng likes this.

Last edited by wyldckat; November 23, 2014 at 10:18. Reason: accidental double post
engrmansoor2534 is offline   Reply With Quote

Old   November 24, 2014, 07:44
Default
  #2
Senior Member
 
Cees Haringa
Join Date: May 2013
Location: Delft
Posts: 307
Rep Power: 6
CeesH is on a distinguished road
Hi,

If you are running a single-phase simulation, you cannot set particle size, since there are no particles. You will need to alter the heat transfer parameters based on empirical correlations in that case; similar to altering the viscosity when you are considering a particulate flow as single phase. Or am I not understanding you correctly?

Best,
Cees
CeesH is offline   Reply With Quote

Old   November 24, 2014, 10:39
Default
  #3
Senior Member
 
Lucky Tran
Join Date: Apr 2011
Location: Orlando, FL USA
Posts: 952
Rep Power: 16
LuckyTran will become famous soon enough
Keep in mind that many assumptions are made with respect to fluid particles in the fluid model.

Simulating nanoparticles dispersed in a fluid (which is multi-phase problem) is different from simulating a fluid with nanoparticles with effective properties (the single-phase problem). Example, in the fluid flow of air or water, we never talk about the size of the air/water molecules).
LuckyTran is offline   Reply With Quote

Old   November 25, 2014, 00:33
Default
  #4
Member
 
Mansoor Ahmed
Join Date: Apr 2014
Location: Pakistan
Posts: 44
Rep Power: 3
engrmansoor2534 is on a distinguished road
thanks to both of you.
so does it mean that we can not study the effect of particles size on heat transfer enhancement if we are considering nanofluid as a single phase flow??
I have read in a research paper that if we consider the effect of brownian motion, then effective thermal conductivity is composed of static part (maxwell theory) and dynamic part (brownian motion), In the dynamic part we have nanoparticle diameter.see picture for detail:
thanks again for your time
Attached Images
File Type: jpg Untitled.jpg (78.0 KB, 35 views)
farah likes this.
engrmansoor2534 is offline   Reply With Quote

Old   November 25, 2014, 02:07
Default
  #5
Senior Member
 
Lucky Tran
Join Date: Apr 2011
Location: Orlando, FL USA
Posts: 952
Rep Power: 16
LuckyTran will become famous soon enough
Quote:
Originally Posted by engrmansoor2534 View Post
thanks to both of you.
so does it mean that we can not study the effect of particles size on heat transfer enhancement if we are considering nanofluid as a single phase flow??
I have read in a research paper that if we consider the effect of brownian motion, then effective thermal conductivity is composed of static part (maxwell theory) and dynamic part (brownian motion), In the dynamic part we have nanoparticle diameter.see picture for detail:
thanks again for your time
The work proposes an equation for calculating an effective thermal conductivity which has contributions from nanoparticle diameter. Ok. But that means once you put in the effective thermal conductivity in Fluent you are done. It's now a single phase flow with an effective thermal conductivity. The fluid doesn't know that there are nanoparticles.

Once you put in effective bulk properties that "account" for the nano particle behavior, you don't talk about nano particles sizes anymore, in the same sense that we stop talking about molecular sizes of individual molecules when we talk about density, thermal conductivity, viscosity, etc.

So I am confused. If you were able to enter the effective properties of the nanofluid, what exactly is the problem here? Did you perhaps put the incorrect property? The statement of your question also states that you have already solved the problem.
LuckyTran is offline   Reply With Quote

Old   November 25, 2014, 02:48
Default
  #6
Member
 
Mansoor Ahmed
Join Date: Apr 2014
Location: Pakistan
Posts: 44
Rep Power: 3
engrmansoor2534 is on a distinguished road
thanks LuckyTran
I got your point. I am now going to simulate the flow with the effective properties I calculated and will consult you in case of any problem.
engrmansoor2534 is offline   Reply With Quote

Old   November 2, 2015, 10:20
Default
  #7
New Member
 
Join Date: Oct 2015
Posts: 9
Rep Power: 2
farah is on a distinguished road
engrmansoor2534 Can i get this paper please?
farah is offline   Reply With Quote

Old   November 2, 2015, 10:21
Default Can i get this paper please?
  #8
New Member
 
Join Date: Oct 2015
Posts: 9
Rep Power: 2
farah is on a distinguished road
Quote:
Originally Posted by engrmansoor2534 View Post
thanks to both of you.
so does it mean that we can not study the effect of particles size on heat transfer enhancement if we are considering nanofluid as a single phase flow??
I have read in a research paper that if we consider the effect of brownian motion, then effective thermal conductivity is composed of static part (maxwell theory) and dynamic part (brownian motion), In the dynamic part we have nanoparticle diameter.see picture for detail:
thanks again for your time
Can i get this paper please?
farah is offline   Reply With Quote

Old   November 2, 2015, 13:54
Default
  #9
Member
 
Mansoor Ahmed
Join Date: Apr 2014
Location: Pakistan
Posts: 44
Rep Power: 3
engrmansoor2534 is on a distinguished road
Quote:
Originally Posted by farah View Post
Can i get this paper please?
Farah I could not find that specific paper, but this one also describes the same behavior of nanofluids. part 1 and part 2 respectively.
www.scielo.br/pdf/bjce/v25n4/a01v25n4.pdf
www.scielo.br/pdf/bjce/v25n4/a02v25n4.pdf
elham-u and farah like this.
engrmansoor2534 is offline   Reply With Quote

Old   November 2, 2015, 14:05
Default simulation of different phases
  #10
New Member
 
Join Date: Oct 2015
Posts: 9
Rep Power: 2
farah is on a distinguished road
Quote:
Originally Posted by engrmansoor2534 View Post
Farah I could not find that specific paper, but this one also describes the same behavior of nanofluids. part 1 and part 2 respectively.
www.scielo.br/pdf/bjce/v25n4/a01v25n4.pdf
www.scielo.br/pdf/bjce/v25n4/a02v25n4.pdf
Thanks alot, I want to simulate phase change material and nanoparticle in Fluent but depending on many published papers they used VOF model the big question is how can i define the different properties because i have 3 phases: 1.solid phase, 2.liquid phase 3.nanoparticle effect?
Any help please
farah is offline   Reply With Quote

Old   November 2, 2015, 14:32
Default
  #11
Member
 
Mansoor Ahmed
Join Date: Apr 2014
Location: Pakistan
Posts: 44
Rep Power: 3
engrmansoor2534 is on a distinguished road
Farah I don't have knowledge about phase change simulations. I am working on nanofluids. you can model nanofluids as a two phase fluid. nanoparticles + base fluid. multiphase models such as mixture model and eulerian models are a good option for nanofluids. If you are interested in particle tracking you can use discrete phase model. it would be better if you downlaod ansys user's guide and ansys fluent theory guide in order to get a proper idea about your case study.
haidernuceng likes this.
engrmansoor2534 is offline   Reply With Quote

Old   November 6, 2015, 08:01
Unhappy nano fluid simulation
  #12
New Member
 
vaibhav
Join Date: Nov 2015
Posts: 3
Rep Power: 2
VAIBHAV WALI is on a distinguished road
Quote:
Originally Posted by engrmansoor2534 View Post
Farah I don't have knowledge about phase change simulations. I am working on nanofluids. you can model nanofluids as a two phase fluid. nanoparticles + base fluid. multiphase models such as mixture model and eulerian models are a good option for nanofluids. If you are interested in particle tracking you can use discrete phase model. it would be better if you downlaod ansys user's guide and ansys fluent theory guide in order to get a proper idea about your case study.
Hi
i am using nano fluids in a pipe which has no inlet and no outlet. the fluid is completely inside the pipe and cant move.

on top of this pipe,in the middle of pipe.i am applying the heat flux. this pipe is embedded in an aluminum block below and convection is happening around the block.
so the heat flux travel down through top of pipe to fluid then to bottom of the pipe then to aluminum block.

i am using single phase for the nanofluids.
my problem is ,the temperature drop on the aluminum is remaining the same ,even if am changing the liquid in the pipe

please help me out.
VAIBHAV WALI is offline   Reply With Quote

Old   November 6, 2015, 11:54
Default
  #13
Member
 
Mansoor Ahmed
Join Date: Apr 2014
Location: Pakistan
Posts: 44
Rep Power: 3
engrmansoor2534 is on a distinguished road
Quote:
Originally Posted by VAIBHAV WALI View Post
Hi
i am using nano fluids in a pipe which has no inlet and no outlet. the fluid is completely inside the pipe and cant move.

on top of this pipe,in the middle of pipe.i am applying the heat flux. this pipe is embedded in an aluminum block below and convection is happening around the block.
so the heat flux travel down through top of pipe to fluid then to bottom of the pipe then to aluminum block.

i am using single phase for the nanofluids.
my problem is ,the temperature drop on the aluminum is remaining the same ,even if am changing the liquid in the pipe

please help me out.
can you kindly attach an image of your flow domain, so it will be easier to understand your case.
Anyways, according to your statement you are modeling natural convection or buoyancy driven flows?
If yes, then if the temperature difference in your domain is large you need to perform a transient calculation in which the initial density of the fluid is computed from the initial pressure and temperature.
On the other hand if your domain temperature difference is small you can perform a steady state calculation using boussinesq model.
In short you should refer to ansys user's guide " modeling heat transfer (natural convection or buoyancy driven flows)" in order to fully understand the setup required for your domain.
thanks
engrmansoor2534 is offline   Reply With Quote

Old   November 17, 2015, 05:20
Default
  #14
New Member
 
vaibhav
Join Date: Nov 2015
Posts: 3
Rep Power: 2
VAIBHAV WALI is on a distinguished road
Quote:
Originally Posted by engrmansoor2534 View Post
can you kindly attach an image of your flow domain, so it will be easier to understand your case.
Anyways, according to your statement you are modeling natural convection or buoyancy driven flows?
If yes, then if the temperature difference in your domain is large you need to perform a transient calculation in which the initial density of the fluid is computed from the initial pressure and temperature.
On the other hand if your domain temperature difference is small you can perform a steady state calculation using boussinesq model.
In short you should refer to ansys user's guide " modeling heat transfer (natural convection or buoyancy driven flows)" in order to fully understand the setup required for your domain.
thanks
thanks for the information
VAIBHAV WALI is offline   Reply With Quote

Old   November 17, 2015, 06:11
Default
  #15
New Member
 
vaibhav
Join Date: Nov 2015
Posts: 3
Rep Power: 2
VAIBHAV WALI is on a distinguished road
air domain.PNG

aluminum heat sink.PNG

copper heat pipe.PNG

cross section of the copper heat pipe.PNG

heat applied on the surface shown in red and light red.PNG

these are the images of the model
Can you please give some insight on this
VAIBHAV WALI is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Waterbell Simulation o.b.m Fluent Multiphase 1 November 5, 2015 06:55
setting up a simulation with multiple interactions phandy OpenFOAM Running, Solving & CFD 1 October 6, 2014 03:16
mass flow rate issue in supersonic nozzle simulation xkang FLUENT 0 July 31, 2014 16:06
Simulation of a complex wing in solidworks flow simulation niels1900 FloEFD, FloWorks & FloTHERM 6 April 20, 2011 10:44
Continuous vs interrupted simulation sega OpenFOAM Running, Solving & CFD 4 November 3, 2008 15:29


All times are GMT -4. The time now is 08:56.