[masoudeh]

Originally Posted by `e`

You can specify how many DPM iterations the solver does until it stops (the default is 500). If the particle stream hasn't escaped the domain within this number of iterations then this stream would be incomplete (finishes partway through the domain).

What path lines are you generating (show us a figure) and what are you expecting (show us another figure)?

this is the path line i got. all the dreams have the same color i want different colors corresponds to velocity.
pathline.jpg
for particle track the streams are incomplete! i will also provide fig for this

[`e`]

Where is the mesh (display the outline only to avoid cluttering) to see the overall shape of the domain? What path lines are you expecting?

You've just quoted my post on how to solve the "incomplete" particle tracking issue, please read carefully...

[masoudeh]

Originally Posted by `e`

Where is the mesh (display the outline only to avoid cluttering) to see the overall shape of the domain? What path lines are you expecting?

You've just quoted my post on how to solve the "incomplete" particle tracking issue, please read carefully...

Hi e

I think i do not understand your question clearly, but the max number of steps for tracking is 500..
this is the path line i expect to seepathline expected.jpg
and this my particle track which i said it is incompleteparticle track.jpg

and this is the path line i got with outline mesh ( i am not sure if u were asking me this!)pathlines meshjpg.jpg

[`e`]

If the particles are incomplete at the end of the simulation then that would indicate they require more steps until they leave the domain.

Your task: change the maximum number of steps for tracking from 500 to say 50,000.

[masoudeh]

Originally Posted by `e`

If the particles are incomplete at the end of the simulation then that would indicate they require more steps until they leave the domain.

Your task: change the maximum number of steps for tracking from 500 to say 50,000.

Thanks a lot for your attention.
Would you please tell me if i just use eulerian approach can it consider the brownian motion?

[masoudeh]

Originally Posted by `e`

If the particles are incomplete at the end of the simulation then that would indicate they require more steps until they leave the domain.

Your task: change the maximum number of steps for tracking from 500 to say 50,000.

I have a message" temperature limited to.." what does it mean? What should I do, does it affect my results? I got results but they not exactly what i expected.

[`e`]

Tackle one issue at a time: have you tried a tracking simulation after increasing the maximum number of steps for tracking to remove the "incomplete" particle problem?

[masoudeh]

Originally Posted by `e`

Tackle one issue at a time: have you tried a tracking simulation after increasing the maximum number of steps for tracking to remove the "incomplete" particle problem?

It works thanks

[masoudeh]

Originally Posted by `e`

Tackle one issue at a time: have you tried a tracking simulation after increasing the maximum number of steps for tracking to remove the "incomplete" particle problem?

this problem solved, thanks.
I got the message that the temperature is limited to..and when i remove the limit form temperature the outlet temperature the software gave me was out of range. Can you help me how to solve it?

[`e`]

Have a read of the Fluent FAQ section on convergence issues and we'll go from there.

[masoudeh]

Originally Posted by `e`

Have a read of the Fluent FAQ section on convergence issues and we'll go from there.

Hi e

I read this part it said the momentum and pressure should be 0.6 and 0.1. I changed mine (pressure 1 and momentum 0.7) to these numbers it becomes worse than before, it gave me the reverse flow message and then increasing sweep and then it said no divergence. these errors came in the first iterations!!
it also said to set k and eps to 0.4 which i could not find out where should i set these.

[masoudeh]

Originally Posted by `e`

Have a read of the Fluent FAQ section on convergence issues and we'll go from there.

I tried to follow the instruction to remove this temperature limited error but it did not work. 1. I do not know how i can solve this error " temperature is limited ..."

2. does eulerian consider interaction between particles? or just eulerian with lagragian could consider this interaction?

Thanks

[`e`]

1. When did this temperature limited error arise, did the simulation previously work and then did you change something?

2. The one- or two-way coupling between the discrete phase (Lagrangian) and continuous phase (Eulerian) dictates the interaction between particles, or lack thereof. Both of these options are available in the DPM of Fluent. Have a read of the "Modeling Discrete Phase" chapter of the user's guide.

[masoudeh]

Originally Posted by `e`

1. When did this temperature limited error arise, did the simulation previously work and then did you change something?

2. The one- or two-way coupling between the discrete phase (Lagrangian) and continuous phase (Eulerian) dictates the interaction between particles, or lack thereof. Both of these options are available in the DPM of Fluent. Have a read of the "Modeling Discrete Phase" chapter of the user's guide.

1. Yes it works fine when i used just eulerian model (DPM with no injection). when I added injection the temperature limited error arise at iteration around#20. When you said to follow the fluent FAQ i decreased momentum and increase pressure to the number in the guid (0.7 and1) and then it gave me this error"reverse flow" and it said no converge!!

2. As it gave me good results with eulerian i preferred to work with eulerian but i was wondering if particles interaction (brownian motion) could be considered in eulerian model?! I know i can use two way coupling but need to be sure eulerian consider solid particles interactions. I read it but still need to know. please give me your opinion.

Thanks

[`e`]

1. Terminology: you're not using DPM if there are no injections. Ensure you're not exceeding the limits of DPM (particle volume fraction etc).

2. I'm familiar with the DPM but not the Euler-Euler approach of modelling particles in a fluid. If your simulations are working in the Eulerian reference frame, then that's great, but you'll need to check the user's manual (or theory guide) for checking how it treats diffusion / Brownian motion.

[masoudeh]

Originally Posted by `e`

1. Terminology: you're not using DPM if there are no injections. Ensure you're not exceeding the limits of DPM (particle volume fraction etc).

2. I'm familiar with the DPM but not the Euler-Euler approach of modelling particles in a fluid. If your simulations are working in the Eulerian reference frame, then that's great, but you'll need to check the user's manual (or theory guide) for checking how it treats diffusion / Brownian motion.

Ok thanks.
Would you please tell me why i got this "temperature limit " error and how can i fix it?

[`e`]

Originally Posted by `e`

Ensure you're not exceeding the limits of DPM (particle volume fraction etc).

Try injecting a small single particle stream of negligible mass flow rate.

[masoudeh]

Originally Posted by `e`

Try injecting a small single particle stream of negligible mass flow rate.

i have done it with 3 single injections (of solid particles) and as my flow is laminar the mass flow rate is very low!

[masoudeh]

Originally Posted by `e`

Try injecting a small single particle stream of negligible mass flow rate.

now i changed the type of injection from single to cone and put 3 particles stream, fortunately it gives me good result and i did not have any "temperature limite" error. but, my problem is when i track particles i just see 1 stream!!
1. i put 3 particles for the cone , i expect i see 3 streams. why i see just 1 stream?
2. i need to see the location of each particle. i mean i want to find out particles motion. can u tell me how should i set particle track to display it for me? i could not find any option in particle track that display the location of each of these 3 particles!

[`e`]

Have a read of the user's guide and tutorials on visualising particle streams; all of your questions are answered there in step by step detail.