Learning Forum

[Mepal]

Hello everyone,

 

I would like to create a simple fluidized bed with wate in a free space between a group of particle.

In Ansys Spaceclaim, I created a simple small vertical cylinder.

In Ansys Fluent 2021R2, I used geometry from Ansys spaceclaim and then allowed inlet air flow from a bottom. I run a calculation, everything went well. 

In Ansys Rocky 2021R2, I used geometry from Ansys spaceclaim and then created a group of particle inside it. A height of particle is half of a cylinder. Then I did two-way coupling with Ansys Fluent (from a step above) and a result showed that the inlet air from a bottom can lift a group of particle inside a cylinder. The result really looked like this video link >>

 

Afterthat, I would like to fill water in a porous zone of particle in Ansys Fluent. However I don't know how to show/import a group of particle created by Rocky in Fluent.

 

My questions are that

1) How to show/import a group of particle created by Rocky in Fluent?
2) How can I fill water in a porous zone of particle created by Rocky in Fluent?

 

Any advice you could give would be much appreciated.

[Rob]

You can't at present. All post processing for the particles is done in Rocky. In the Fluent solver have a look at the UDMs as (I think) volume fraction is passed back. You can then define a region based on volume fraction, separate the cells and set the porous coefficients. 

[Mepal]

Thank you for your help, Rob.

 

I've followed your suggestion and found that it is true Ansys Fluent will receive data (in UDMs format) from Rocky during the simulation.

According to Ansys Rocky User Manual (21.2.0),  an "Additional Inputs" lists items that Fluent will receive from Rocky during the simulation, which Rocky instructs Fluent to create as User Defined Memories (UDMs). And "Additional Outputs" lists the items that Fluent will share during the simulation with Rocky.

However, on my Variables tab, nothing showed.

If I understand correctly, I must create an additional input on the variables tab.

Could you please guide me how can I define the variable I need (in this cas is VoF of particles) in the variables tab to pass back into Ansys Fluent?

[Rob]

Open Fluent and check the User Defined Memory under the Contour panel. I can't remember what each represents (it's in the Rocky manual) unless they got the naming part to work (I've not tried it recently). I don't think you need to do anything in Rocky as the UDMs you're plotting are what Fluent needs to handle the 2-way part of the simulations. 

[Mepal]

Hello Rob,
 
Thank you for your guidance and time. I followed your suggestion by reading Rocky's manual and found that on page 71, they indicated the UDMs in Fluent resulting from two-way coupled simulations. (Ref, ESSS Rocky, Release 2022 R2, CFD Coupling Technical Manual,
ESSS Rocky DEM, S.R.L., (2022).)

Then, I defined the number of UDMs location for 14 in Fluent.

In Rocky, I found that 14 UDMs I created in Fluent were available in the variable “from Fluent to Rocky”, not “from Rocky to Fluent”. 

I am curious, why did the UDMs I created in Fluent not be available in "From Rocky to Fluent"? (That is the reason why I think that I should create UDMs in Rocky not in Fluent, but I did not find the way to do it.)

Could you please correct me if I am wrong.

[Rob]

Rocky will add the UDMs automatically, if you've added 14 into Fluent, check UDM 14-27 in Fluent. What you've now got is the ability to pass additional data from Fluent to Rocky: typically for doing things with Rocky's API coding functionality.