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Old   December 3, 2012, 05:12
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milad
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hi
what is difference between steady particle tracking and unsteady particle tracking?
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Old   December 3, 2012, 08:22
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Hi Milad,

Well the difference is the same as the difference between steady state solution and transient solution. In Steady particle tracking the entire particle trajectory is computed until the solution gets converged. More mathematically, the Lagrangian trajectory integration time is from t=0 to t=inf. However in unsteady particle tracking, the Lagrangian integration time is between the assign values (say t=0 to 1e-06 and so on).

Hope that helps
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Old   December 5, 2012, 12:34
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Hi Barzin
thanks a lot. I don't understand. I think that in steady particle tracking derivative time is zero so means d/dt=0 therefore velocity is constant and it's meaningless because of Lagrangian approah is always unsteady. so why dpm modeling in fluent has steady particle tracking?
I don't understand this contradiction. please explain it.:(:(
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Old   December 6, 2012, 05:25
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Milad jan

Why do you think it's meaningless? plus it doesn't mean that particle velocity is constant through out the trajectory. imagine that you solve a continuous flow in a pipe. In steady calculation if the initial velocity at inlet is constant, the velocity will decay along the pipe. I think you can adapt this to a particle trajectory calculation.
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Old   December 7, 2012, 08:57
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His Barzin, I have a question too, assume that in a unseady problem, in the steady particle tracking, only the entire particle trajectory is computed until the end of the calculation ? that does not make sense
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Old   December 7, 2012, 12:29
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Hi mate,

Sorry I did not get the question. Can u please shed more light?
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Old   December 8, 2012, 05:33
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I am sorry for that. What I dont understand is that "Lagrangian trajectory integration time is from t=0 to t=inf"?
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Old   December 8, 2012, 07:05
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Don't worry, I got you now, This mean the whole particle trajectory!
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Old   January 23, 2013, 07:00
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Hi Dears

I have a air flow which enter a cavity and exit it,I want to add some particles to the flow which has a lift and drag(I'm going to change their direction by magnetic fields)...How can I determine the diam and number of particles,velocity,permaebility and density and....

In which panel this settings exist??

Thanks a lot
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Old   January 28, 2013, 11:01
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Hey Payam,

You need to have a deeper look in DPM and injection panel! I'm sure you'll able to find it.
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Old   January 29, 2013, 07:33
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Quote:
Originally Posted by barzin View Post
Hey Payam,

You need to have a deeper look in DPM and injection panel! I'm sure you'll able to find it.
But when I change the air by Water it doesn't work.My problem is "Fe" particles which is immersed in Water.But I'm not sure that Dpm is the model I should use!

Thanks
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