Learning Forum

[Mohammad Raihan Arfin]

Hi Everyone,

I'm trying to model the speices transport for the carbon dioxide methanation reaction in a microchannel reactor with dimension 50*0.45*0.15 mm, for which I have the chemkin format files for gas phase kinetics, thermodynamic data and surface chemistry data with extenions .inp, .db and .che respectively. However, when I try to import these files in fluent it closes abruptly with some error message but since it just closes almost instantenously, I'm not able to read the error message. Can anyone help me with this.

Also, I was wondering how may I define the catalyst coated layer in my fluid domain? As it can be seen the attached figure I have created the geometry using design modeler, where there is a outer solid body and inner fluid body, I have named the outer surfaces as solid wall and the inner fluid body which is the fluid domain as inlet and outlet at the left and right end, but I have doubts about naming and defining the catalyst layer, here I have named the fluid domain walls as catalyst layer but I am doubtful about it. How can I do so, and according the geometry which I created and imported in fluent the following messages pops up which I don't really understand the meaning of.

["At least one many-to-many mesh interface is found in the case file. Such mesh interfaces will not be available in a future release of Fluent. It is recommended to convert to the current default one-to-one mesh interfaces with the following text command:

/define/mesh-interfaces/one-to-one-pairing? yes

Done.

Preparing mesh for display...

Note: zone-surface: cannot create surface from sliding interface zone.

Creating empty surface.

Note: zone-surface: cannot create surface from sliding interface zone.

Creating empty surface.

Note: zone-surface: cannot create surface from sliding interface zone.

Creating empty surface.

Note: zone-surface: cannot create surface from sliding interface zone.

Creating empty surface.

Done.

Setting Post Processing and Surfaces information ...Note: zone-surface: cannot create surface from sliding interface zone.

Creating empty surface.

Note: zone-surface: cannot create surface from sliding interface zone.

Creating empty surface.

Note: zone-surface: cannot create surface from sliding interface zone.

Creating empty surface.

Note: zone-surface: cannot create surface from sliding interface zone.

Creating empty surface.Done."]

Also, I didn't find any tutorials about setting the model for catalytic reaction including the surface chemistry.

I'm bit new to ansys so don't really about sources where I can get any help from. Any help would be much appreciated. I am attaching the pictures for reference.

[SVV]

Hi,

 

You will be able to find .trn or .log file in the working directory. The error message on the cause of failure will be mentioned in these files.

I would recommend going through the tutorials :Chapter 18: Modeling Surface Chemistry (ansys.com) and Chapter 19: Selective Catalytic Reduction Simulation (ansys.com) to learn how to set up a catalytic reaction in Fluent.

[SVV]

As for the many to many interface issue, you can use the following method to over the same.

Initially, remove the mesh interface and then enter the following TUI command in the console.

/define/mesh-interfaces/one-to-one-pairing? yes

Then recreate the mesh automatically.

If there is no specific requirement on creating mesh interface, I would recommend creating conformal mesh using share topology to overcome this issue.

[Mohammad Raihan Arfin]

Thank you so much for your reply. As I prevoiusly mentioned, as soon as I import the files, fluent closes abruptly so I can't access the files as when I reopen it then a new fluent window opens where I have to redo the modelling from the beginning and no previous data is resotred. I tried to access the links copied in your reply, however, it redirects to fill in the form where details including the ansys account number are required, which I don't have as I have the institutional license, though I went through it using web browser and I am using a different way of modelling than this tutorial, I'm modeeling the surface reaction where by writing the chemkin files for gas phase, thermodynamics and surface reaction data and then try to import it in fluent but the problem is it doesn't import and closes, however, when I just import the gas phase file for modelling reaction where only gas phase reaction is taking place then it successfully imports and the simulation runs fine. so, my problem is why it doesn't import the chekmin files?

Also, I would request you to please provide some tutorial about geometry design in design modeler for creating and defining the catalyst layer in fluid domain, also, I'm not able to access the chapter:19 link provided in your reply as it redirects to fill Ansys Customer Support Space Registration Form, in which I don't know the customer number. Thanking in anticipation.

[Mohammad Raihan Arfin]

Hi V.V,

I was trying to import the files one at a time, and then the error message got displayed as fluent didn't close, it displays the following error:

when I import gas kinetics file and thermo files it reads "the solver couldn't read chemkin input files, please check those files"

when importing only the surface kinetic file 

Error: Please Enter CHEMKIN File Name

ErrorObject: #f

 

I'm attaching the screenshot of my thermo and surface data chemkin file here. I hope it will help you in finding out the problem. Thanks