Learning Forum

[Vicky]

Hello,

I want to make some plots in post-processing (Particle velocity vs. radial distance of the pipe); therefore, I exported the DPM variables of my injection with the following option:

To export: File > Export > Particle History Data 

 Then, in post-processing, I imported the file, but when I selected the option variable, I got this: 

(In addition, I would like to obtain the Mean values to visualize in an Eulerian Framework)

 

I appreciate your help. Thank you.

 

 

[Rob]

You'll be better off doing the post processing in Fluent. Are you running the particles steady or transient? 

[Vicky]

Hi Rob, thanks for replying and sorry for the inconvenience with the other post.

I am currently working with transient, I would like to find the particle velocity profile when the fluid is fully-developed.

I'm working with DPM option (I have a small particle volume fraction and the particle diameter is 1.8 mm).

 

 

 

[Rob]

OK, you don't have a particle velocity profile as such, you have point data as a particle (stream) passes through a plane. However, if you turn on the Contour plot option Fluent will average some of the DPM values into the cells. Depending on how many particle steams you have this may produce a "spotty" contour, post what you see for comment. 

[Vicky]

Hello Rob, 

I simulated using the following options because when I don't activate the unsteady particle tracking with the unsteady flow, the solution doesn't converge.

I have drawn a line in the cross-section and I have obtained this result

I appreciate any feedback you can give me on this subject.

Thank you.

[Rob]

Looks sensible, how many particles are you tracking, and if transient has the number in the domain stabilised?

[Vicky]

Hello Rob, I am injecting 624 particles and tracking 632998 particles.

Initially, I simulated it with just air and the flow became fully developed a short distance from the start. My question is how can I be sure that my air-particle flow is stabilized? Currently, my pipe is 10 meters long.

[Rob]

With transient particles you need to see when the number stabilises. Otherwise, the usual residual and monitors are sufficient. Some images of results may help. 

How large are the particles relative to the geometry and cells?