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KK February 11, 2008 21:11

Number of particle positions in Lagrangian model
 
Hi,

I want to use Lagrangian model for particle tracking in Transient simulation using one way coupling in between solid particles and fluid. Hence solid particles will be insterted at the last time step.

I have to specify 'Number of Positions' of the these particles and one option given in CFX-Pre allows to set particles per second(called 'Direct Specification'). Suppose I want to track 1000 particles at once, then, do I need to divide it by my time step (say 0.0001 sec) in order to get sensible number of particles per second? I am worried if I mention 1000 particles and if solver divides it by time step then only one particle will be tracked. If it does not calculate that way then I should not specify 1000/(time step).

Please help.

Thanks, KK

Elisabetta February 12, 2008 06:08

Re: Number of particle positions in Lagrangian mod
 
Hello KK,

don't think that the number of particle is divided by your timestep.

Regards

Elisabetta

KK February 12, 2008 15:31

Re: Number of particle positions in Lagrangian mod
 
Thank you very much Elisabetta, I specified 10^5 partciles under 'Direct Specification' (CFX-Pres shows unit to be per second) and my time step was 0.0002 seconds. I noticed that the solver was injecting 20 particles per time step. That makes sense that total number of particles injected in one second would be 10^5. is it correct?

Elisabetta February 13, 2008 06:33

Re: Number of particle positions in Lagrangian mod
 
Yes I think it is correct.

Ciao

Elisabetta

Roghayyeh Motallebzadeh February 16, 2008 05:56

Re: Number of particle positions in Lagrangian mod *NM*
 


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