[masoudeh]

Originally Posted by `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.

Thank you!

[masoudeh]

Originally Posted by `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.

I read it before but i could not find my answers that is the reason i ask here, i wish someone who has the experience help me, sometimes the answers are not clearly available in userguids. any way, thank you for the suggestions

[`e`]

The Fluent developers have gone to a great deal of effort to create the user's guide, and this documentation should be your first point of reference. Use the contents of the document to navigate to relevant sections (similar to a textbook).

Here's the name of sections that correspond to your questions (all in the "Modeling Discrete Phase" chapter):

Originally Posted by masoudeh

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?

"Displaying of Trajectories" guides you through visualising particle streams of all injections and how to track a single particle stream.

Originally Posted by masoudeh

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!

"Step-by-Step Reporting of Trajectories" shows you this task exactly.

[masoudeh]

Originally Posted by `e`

The Fluent developers have gone to a great deal of effort to create the user's guide, and this documentation should be your first point of reference. Use the contents of the document to navigate to relevant sections (similar to a textbook).

Here's the name of sections that correspond to your questions (all in the "Modeling Discrete Phase" chapter):



"Displaying of Trajectories" guides you through visualising particle streams of all injections and how to track a single particle stream.



"Step-by-Step Reporting of Trajectories" shows you this task exactly.

Hello ,

I got the particle tracks. but the particles positions are not what i expected to be in turbulent flow. Could u please tell me which part of the model i need to work to get better results for the particles movements. (now, the particles are moving in straight line but i expect the particles near wall move toward the center of the tube)

Thanks

[masoudeh]

Hello

would u please help me how can i include particle particle interaction in the model?

Thanks

[`e`]

For four-way coupling (includes particle-particle interactions) you could try using the DEM collision model in Fluent within DPM. This DEM collision model is for modelling granular particulates, or similar large particles. If you want to include other interaction forces besides physical collisions (for example between colloidal particles) you may need to create your own UDFs for this functionality.

[masoudeh]

Originally Posted by `e`

For four-way coupling (includes particle-particle interactions) you could try using the DEM collision model in Fluent within DPM. This DEM collision model is for modelling granular particulates, or similar large particles. If you want to include other interaction forces besides physical collisions (for example between colloidal particles) you may need to create your own UDFs for this functionality.

Hi

Thanks for the respond. I could not find DEM in user guide. Could u tell me how can i activate it?

Thanks

[`e`]

Check the chapter on "Modeling Discrete Phase". Specifically, section "24.2.5.12. Modeling Collision Using the DEM Model" (for ANSYS Fluent 15.0 Users Guide; might be a different number for another version).

[masoudeh]

Originally Posted by `e`

Check the chapter on "Modeling Discrete Phase". Specifically, section "24.2.5.12. Modeling Collision Using the DEM Model" (for ANSYS Fluent 15.0 Users Guide; might be a different number for another version).

thank u, i could find it.
1.just not sure if i need to use granular or interfacial in secondary phase?! my secondary phase are solid particles (4e-8m), heat and mass and momentum are important phenomena in my case.

2. to consider the particle particle interaction should i choose Coalescence Kernal and Breakage Kernel in interfacial case? what about the granular case, should i choose the radial distribution?

Thank u

[masoudeh]

Originally Posted by `e`

Check the chapter on "Modeling Discrete Phase". Specifically, section "24.2.5.12. Modeling Collision Using the DEM Model" (for ANSYS Fluent 15.0 Users Guide; might be a different number for another version).

By the way i read in the limitation of the Eulerian model that it can not consider particle particle interactions! so by choosing Coalescence Kernal and Breakage Kernel can i activate this interaction?

[`e`]

I'm not familiar with these Kernel methods, have you read the Theory Guide?

The chapter I directed you to was on the Discrete Phase Model (DPM) which tracks particles in the Lagrangian reference frame. Your continuous phase is tracked in the Eulerian reference frame which makes it an Euler-Lagrange model overall.

[hamid2016]

hello all
i'm working on a fsi problem and want to set lagrangian-eulerian mesh to my domain. how should i do that?
thanks in advance
hamid

[Nuha]

i m working on a gas-solid-liquid fluidized bed .Its Geometry is a simple 2D cylindrical column. I have used eulerian-lagrangian approach to track the solid particles. As per this approach dense discrete particle model (DDPM) with DEM collisions is used in fluent 15.0.
During simulation as a first step , i kept gas velocity equal to zero in boundary conditions & selected surface injections in DDPM to inject solids from bottom of column i.e from gas inlet. I have to inject 800 particles which will give 0.25 m static bed height (as per literature), but in my case only 0.125 m static bed height is obtained. Kindly let me know how could i get the required 0.25 m static bed height just after the surface injection?
Secondly, just to see the phenomena of fluidization at 0.125 m static bed height, i gave following boundary conditions:
• 1.4 m/s gas velocity as inlet boundary condition from bottom of cylinder
• 0.012 m/s liquid velocity from top as inlet BC
• -0.02783 m/s liquid velocity from gas inlet
• “Reflect” as solid collision type in DPM with “Anthracite” as collision partner
• No slip condition for both solids & gas
• Pressure as outlet boundary condition

Upon simulating it, i didn't get a proper fluidized bed rather a packed bed moving upward as a lump is obtained, which isn't matching to any of fluidization stage.
Kindly tell me where is the actual problem, either in BC , injections or in selecting drag laws?

[Abdulrajak Buradi]

Dear Sir,
I want know how to enter the number of particles in DPM Injection, and were I should specify the number of particles.

[pachi]

Hiii ,
am looking particle residence time in the flow field.

Along with the water and injecting some 5 microns diameter of particles with a velocity of 0.042m/s, here i have not mentioned the total mass flow rate in the injection frame.

Is this mainly affect to the flow field and am getting confuse with how to calculate total mass flow rate.

Currently, injection time am calculating based on the particle velocity(0.0425m/s) and my domain length(5m) soo travel to this length it needs approximately 117s. IS this correct.
Please let me know am worried too much.

[pachi]

Originally Posted by `e`

I'm not familiar with these Kernel methods, have you read the Theory Guide?

The chapter I directed you to was on the Discrete Phase Model (DPM) which tracks particles in the Lagrangian reference frame. Your continuous phase is tracked in the Eulerian reference frame which makes it an Euler-Lagrange model overall.

Hiii,,

am looking particle residence time in the flow field.

Along with the water and injecting some 5 microns diameter of particles with a velocity of 0.042m/s, here i have not mentioned the total mass flow rate in the injection frame.

Is this mainly affect to the flow field and am getting confuse with how to calculate total mass flow rate.

Currently, injection time am calculating based on the particle velocity(0.0425m/s) and my domain length(5m) soo travel to this length it needs approximately 117s. IS this correct.
Please let me know am worried too much.

[Zari]

Originally Posted by mali28

Hi,

Also specify the number of particle streams.

Hi,

looking for my questions, I saw this discussion, and appreciate if you explain me how 'the number of particle streams' should be set?

I have these inputs:

-total injection flow rate (1.5 e-4 kg/s)
-the injection hole diameter (0.1 mm)
-injection type (pressure swirl atomizer)

should I approximate the particle diameter to set the number of the streams?
or is it a mesh-related parameter?
or the statistical convergence issue?

thank you in advance.
Zari