thank you for prompt reply.
did you figured out the problem?
however if i write udf using DEFINE_DPM_OUTPUT than how to use it further as a injection file as injection file has format like [ ((injection-0 ((type . inert) (injection-type . surface) (numpts . 1) (dpm-fname . " ") (surfaces 31 33) ].

Thanking You

Piyush

Today only posted the query at the following link and I'm stuck at compiling as interpretting is not working, have to install Visual Studio, will post the progress if I get to there...

http://www.cfd-online.com/Forums/flu...es-outlet.html

fully developed flow in the inlet
 

hi,
im trying to simulate graetz problem in fluent. for this i need to form a fully developed flow in the inlet. i tried in by importing the profile of the outlet of same dimension,same mesh specifications geometry and import in to the inlet.but this really did not work. i tried appling the specific x velocity component and the x velocity after the fully developed flow as well. but still i cannot simulate the fully developed profile in the inlet.i tries inverse distance method in interpolation as mentioned in previous thread but still the results are the same. i do really appreciate your kind help on this matter thank you.

fully developed flow in the inlet
 

Have you checked that at outlet velocity profile is fully developed ? First check this. I mean channel length should be sufficient. If you are sure that at outlet velocity profile is fully developed then write the profile for x-velocity, y-velocity at outlet. In next simulation read this profile at inlet. Change the inlet boundary condition for velocity specification method as "components" and apply outlet x-velocity for x component and outlet y-velocity for y component.

hi every body
 

How can i write the profile of two different velocity ? and then import it to my geometry with two inlets?

please help me

How can i write the profile of two different velocity ? and then import it to my geometry with two inlets?

please help me

write the profile
 

You have only one outlet or more than one outlet in your geometry.

2 inlet and one outlet

write profile
 

There is no need to write two profile. First write the profile of properties at outlet like velocity, turbulence and others, what you want to apply at inlet. Then in next simulation read this profile at inlet and apply the properties at inlet according to your problem.
You can do this by writing two different profile at outlet for inlet (i.e. for two inlet) and then apply at each inlet separately.

hope u will do this

i mean that when i want to read both profiles.the soft ware (fluent) just read the last profile that u read .

Is there a way to write UDF to automate exporting a profile at the outlet and use it as an inlet condition in the same case?

internal surface extract?
 

Is it possible to extract profile from surface which is not outlet or inlet- internal?

Yes as long as it shows up in selection menu. I have done it at interfaces etc.

Tanks for the fast reply :)

manual CFD
 

Hi guys
please i am new user for Ansys fluent
anybody could to send me manual about how to use Ansys fluent? and pls let me know how to add inlet velocity in fluent ansys?
this is my email
alburkatyhasan@gmail.com
many thanks
hasan

How to create a profile for poison in Ansys fluent
 

Hi guys!
I'm doing cfd simulate of engine.
And i want to give the velocity to the poison but idon't know how to create the external profile for giving this so ineed your help.
Please mail me the suggestion asap.
vipulparmar174@gmail.com

problems using profile as inlet boundary condition
 

Dear all,

I am trying to use an outlet profile as inlet BC for a RANS simulation (turbulence modell: Reynolds-Stress, stress-omega) in a backward-facing step using Fluent.
I have the coordinates, all velocity components, pressure, turbulent kinetic energy, turb dissipation rate, specific dissipation rate and Reynolds stresses exported from a simulation in CFX.
After reading the profile, using it in the inlet boundary condition and initializing the simualtion I checked the contours at the inlet and received the following errors:
1. x,y,z-velocities are lower than in my exported profile (e.g. max velocity in the profile file was 0.46m/s in Fluent it is now 0.4 m/s)
2. tke, sdr, tdr and Reynolds stresses are not shown as a profile but as a constant value over the inlet (this value is again lower than in the profile data)
3. Reynolds-stresses uv, vw, uw are set to 0

I have checked the coordinate system, the units and the velocity vectors, all seems fine.

Have you had this error before? Do you know what could be wrong?

This is how I do it:
1. Adapt the CFX profile to Fluent syntax
2. Fluent: Boundary conditions > Profiles > Read Profile > choose .prof file
3. set velocity inlet: velocity specification method: Components (choose x,y,z velocities from profile); turbulence specification mehtod: k and epsilon (choose k and epsilon from profile); Reynolds-stress specification method: Reynolds-stress-components (choose stresses from profile)
4. Initiliaze

Thanks a lot for your help!

Exporting an outlet profile to an inlet is not so straightforward. It sounds like you did everything right except maybe...


When you export it at the outlet, it takes the coordinates (x,y,z)'s at the outlet location. You inlet is (probably?) at a different location. Then when it interpolates from the old coordinates to the new, it causes these errors because your new locations.


If this is the case, you need to translate the coordinates at the outlet to the inlet. Either you edit the text file generated using a text editor, or you translate the mesh in CFX before you export it so that it can be read properly.

I'd like to do the same thing, creating a UDF to automate the export of the outlet profile and then using it to define the inlet at every time step. Does anyone know how to go about this?