dpm modeling
hi
what is difference between steady particle tracking and unsteady particle tracking? 
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 1e06 and so on). Hope that helps 
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.:(:( 
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. 
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

Hi mate,
Sorry I did not get the question. Can u please shed more light? 
I am sorry for that. What I dont understand is that "Lagrangian trajectory integration time is from t=0 to t=inf"?

Don't worry, I got you now, This mean the whole particle trajectory!

Dpm
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 
Hey Payam,
You need to have a deeper look in DPM and injection panel! I'm sure you'll able to find it. 
Dpm
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Thanks 
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