Postprocessing using CFD Post -Problem/Help
 

Hi Friends
I am doing a CFD heat transfer Simulation using Fluent and I need to find the outlet temperature for a given Inlet temperature and velocity and in my case there is a sphere inside a channel of Fluid...so There will be heat transfer from the hot fluid to the sphere..And hence I need a graph showing the outlet temperature based on the time in seconds...so
For Ex
Inlet temp = 370 K
Sphere 7 Initial Fluid Temperature = 300 K
And have to find the out let Temperature say after 5 seconds or something..should I use Transient simulation or Steady state will be enough...?? Am a beginner kindly help me...:(

Steady State or Transient
 

Hi Friends

Can anybody tell me whether the Transient simulation is the same as periodic boundary condition ..??

I have to calculate the outlet temperature after 5 seconds for a flow above a sphere which is in atmospheric temperature(300K)...and the inlet temperature is 370 K..So kindly tell me whether the periodic boundary condition is the same as doing transient simulation or both are different..??

Hi
What do you mean by saying that periodic boundary condition is the same as transient simulation? I can't make any sense from your points. Transient simulation is kind of simulation which depends on time and flow properties at each point change with time but, periodic boundary condition depends on the geometry of your model. For instance, in a stirred tank, you can consider only a quarter of the tank in your model instead of modeling the whole tank as long as all angular conditions inside the tank is similar, i.e. there's no baffle or feed pipe. Periodic boundary conditions requires its own strategy when you model your geometry, I mean some adjustments in modeler. As far as I know there's a tutorial regard this in fluent I suppose a series of pipes that hot air flows above it. Hope it help.

Ah ok..
For me also I have to consider only a quarter of the geometry and is named as symmetry in all the faces around...But the problem is I have to find the temperature at the outlet of the duct say after some seconds...and its mainly to study how much temperature is absorbed by the metal cube inside the duct

Hi again
Maybe you need to do your simulation by considering both periodic and transient conditions. If you give me more details of your work, maybe I'll be able to help you.

Hi hope you got my message..kindly reply to my msg when you are free...