[HeatPro]

Hey, guys!
There is a tutorial called "Modeling bubbling fluidized bed using DDPM+DEM" available in Customer Support portal. In this tutorial a fluidized bed containing about 90 thousand particles is modeled.

Particles are injected by means of an injection file from 0 to 1e-08 seconds.
Here is a part of their file:
((-0.098104 0.007238 -0.198122 0.0 0.0 0.0 0.000750 300.000000 4347.826018) injection:0)

Why does the mass flow rate equals 4347.826018 kg/s???(for all particles)
How was it calculated?

Judging from what I've read on the CFD forum, the mass flow rate of a single particle is the particle mass divided by the injection time, right?

However, assuming that density equals 1600 kg/m3,
the mass is 3.534e-07 kg and time is 1e-08 seconds,
the mass flowrate finally equals 35.34 kg/s (123 times less than their).

Please, help us sort it out. You reply is extremely welcome!Lagrange.jpg

[Sankaranand]

Hello @HeatPro, did you get to know how the mass flow rate was calculated? I would appreciate your response. Thank you.

[Sankaranand]

Originally Posted by Shaheer

I really think there should be a tutorial for these things you know!
I tried to access my files with the format but no avail.
I tried to fit in your file and mine but sth didnt click so instead of create injection i read the injections and well in both case it seems i am getting this
//rror: CAR: invalid argument [1]: wrong type [not a pair]
Error Object: name
Importing the following injections:

Error: CAR: invalid argument [1]: wrong type [not a pair]
Error Object: name//

Do you face the same issue ever?

I tried to read his .inj file and I get the same error as yours. Could you please tell me if you got it working?

[sonnet]

can anyone helpme out here. io have tried to atch the following file for injection as .inj file. but it is not working
(( x y z u v w diameter temperature mass-flow ) name )
(( 30 0 -140.98 0 0 31.678 0.25 288 0.5 ) 1 )
(( 28.97777479 7.764571353 -140.98 0 0 31.678 0.25 288 0.5 ) 2 )
(( 25.98076211 15 -140.98 0 0 31.678 0.25 288 0.5 ) 3 )
(( 21.21320344 21.21320344 -140.98 0 0 31.678 0.25 288 0.5 ) 4 )
(( 15 25.98076211 -140.98 0 0 31.678 0.25 288 0.5 ) 5 )
(( 7.764571353 28.97777479 -140.98 0 0 31.678 0.25 288 0.5 ) 6 )
(( 1.83772E-15 30 -140.98 0 0 31.678 0.25 288 0.5 ) 7 )
(( -7.764571353 28.97777479 -140.98 0 0 31.678 0.25 288 0.5 ) 8 )
(( -15 25.98076211 -140.98 0 0 31.678 0.25 288 0.5 ) 9 )
(( -21.21320344 21.21320344 -140.98 0 0 31.678 0.25 288 0.5 ) 10 )
(( -25.98076211 15 -140.98 0 0 31.678 0.25 288 0.5 ) 11 )
(( -28.97777479 7.764571353 -140.98 0 0 31.678 0.25 288 0.5 ) 12 )
(( -30 3.67545E-15 -140.98 0 0 31.678 0.25 288 0.5 ) 13 )
(( -28.97777479 -7.764571353 -140.98 0 0 31.678 0.25 288 0.5 ) 14 )
(( -25.98076211 -15 -140.98 0 0 31.678 0.25 288 0.5 ) 15 )
(( -21.21320344 -21.21320344 -140.98 0 0 31.678 0.25 288 0.5 ) 16 )
(( -15 -25.98076211 -140.98 0 0 31.678 0.25 288 0.5 ) 17 )
(( -7.764571353 -28.97777479 -140.98 0 0 31.678 0.25 288 0.5 ) 18 )
(( -5.51317E-15 -30 -140.98 0 0 31.678 0.25 288 0.5 ) 19 )
(( 7.764571353 -28.97777479 -140.98 0 0 31.678 0.25 288 0.5 ) 20 )
(( 15 -25.98076211 -140.98 0 0 31.678 0.25 288 0.5 ) 21 )
(( 21.21320344 -21.21320344 -140.98 0 0 31.678 0.25 288 0.5 ) 22 )
(( 25.98076211 -15 -140.98 0 0 31.678 0.25 288 0.5 ) 23 )
(( 28.97777479 -7.764571353 -140.98 0 0 31.678 0.25 288 0.5 ) 24 )
(( 30 -7.35089E-15 -140.98 0 0 31.678 0.25 288 0.5 ) 25 )

[alexdolabella]

I was also having problems with Fluent not reading my .inj, despite my formatting seeming correct.

What I found out was that I was saving the .inj using Unicode encoding in Windows Notepad. After I changed to ANSI encoding, it worked!

[Wang Changjun]

Hello, sorry for my poor English. You will understand all by checking "Report→Summary" in Fluent. I hope it can help you.

[Tarekpower1]

Originally Posted by Sankaranand

I tried to read his .inj file and I get the same error as yours. Could you please tell me if you got it working?

Please did you find answer for this

[Tarekpower1]

please can you send to me the injection file 92Kparcels.inj

[ghost82]

Originally Posted by Tarekpower1

please can you send to me the injection file 92Kparcels.inj

Here it is:

https://www2.zippyshare.com/v/ukUfURSA/file.html

[Tarekpower1]

thanks alot

[CFDlearner1]

In IC engine combustion simulation an injection mass profile is needed but as I'm new to fluent i don't know how to create and proceed. Your kind help will greatly be appreciated.

[anam ali]

I am using Eulerien dense discrete phase model in Ansys Fluent for modeling diesel spray in a constant volume chamber. In fluent injection, particle initial conditions can be read from an external file. I write six injections in a one file, the file has the following form:
((x y z u v w diameter temperature mass-flow) injection0:ID)
When I run the simulation it give the error
“ERROR reading particle 0 for injection: injection-0”
Can anybody suggest me the solution to this problem?
Thanks in advance.

[sanmi]

Pls, can someone send me the 92Kparcels.in file.

[sanmi]

Originally Posted by ghost82

Here it is:

https://www2.zippyshare.com/v/ukUfURSA/file.html

This file does not exist on the provided link. Can someone help with the file?. Is there a tutorial on writing an injection file?. If there is, can someone also share the link?.

[ali.faghani]

Hi
Excuse me, is it possible to simulate a nanofluid (zero velocity) using the Discrete Phase Model(DPM) at Ansys Fluent? Could you please help me?
When the Nanofluid enteres the tube at a certain velocity, I can inject the particle into the tube as <surface> and take its velocity equal to the velocity of the base fluid, and simulation will occur.
But at zero Velocity i dont know how to inject the particles
Regards

[khalid.elserfy]

Originally Posted by ghost82

Hi Shaheer,
as I wrote in the other post, you can create an injection file to load your volume.

The injection file must have this format (check in fluent guide!!):
(( x y z U V W particleDia particleTemperature massFlow) injection:0)

x: x coordinate in m
y: y coordinate in m
z: z coordinate in m
U: x velocity in m/s
V: y velocity in m/s
W: z velocity in m/s
particleDIA: particle diameter in m
particleTemperature: particle temperature in K
massFlow: particle mass flow in kg/s
injection:0 --> name of the injection

Now, you have an excel file, not formatted as you want: all you have to do is to automatically format your excel data into a new injection file, so it can be read in fluent. You can program in visual basic, or what you want, or this can be easily done in excel itself.

For example, you have in your excel file, in sheet1:

Column A: x coordinate in m
Column B: y coordinate in m
Column C: z coordinate in m
Column D: temperature in K

Column E (create it): progressive numbers starting from 0, step +1 (so you have E1=0, E2=1, E3=2 and so on).

All your particles have 1 mm diameter.
You set a time step for the transient simulation of 0,01 s.
You set end time of injection at 0,01 s.
Your particles have a density of 1500 kg/m3.

In another sheet of excel you can write in A1 cell:
Take cell values from sheet1

="(( " & A1 & " " & B1 & " " & C1 & " " & "0.0 " & "0.0 " & "0.0 " & "0.001 " & D1 & " " & "0.00007854) " & "injection:" & E1 & ")"

Value of 0.00007854 is derived by:
you have a particle with a volume of 5.24e-10 m3.
Your particle has mass of 7.85e-7 kg
You inject your particle during 0.01 s, from time 0 s to 0.01 s (time step 0.01 s): you are injecting at 0 m/s velocity your particle once (i.e.: you are loading your volume only at the first time step).
0.00007854 = 7.85e-7 / 0.01

Now you have the first string for your first particle.
Now drag down that cell to aoutomatically complete all the remaining strings for all your particles.

Once finished, copy your new sheet2 into a txt file and rename it.

NB: before all, try to inject a single particle to see if it works and check carefully in fluent user guide format of the injection file.

Daniele

hi
i want to ask if i want to describe a static powder particles in a powder bed, how much i have to set the powder particles mass flow rate (kg/s)??

thanks

[rezaamininiaki]

hi, thanks for your explanations and code also,
I have a question,
instead of 2 particles if I want to inject 10000 particles at different positions how can I select random positions?
in this case, how can I write my file?
thanks