ANSYS Fluent Tutorial | How to Add the Transient Table Data Boundary Condition | Fluent TUI Tutorial

[@kosta765]

You are amazing guy! Extremely clear explanation. Even Ansys tech support cannot do that

[@AnsysTutor]

Thank you.

[@ndibakarareddy236]

Thanks man..... Finally, I got here... looked so many places but couldn't find.

[@AnsysTutor]

Most welcome 🙂🙂🙂

[@HENGELWIN]

Thank you for your very clear and detail explanation problem. I was having problem in creating a reflow profile and go through so many online search. Your video solve my problem. Really appreciate, Thank you!

[@AnsysTutor]

You are most welcome.

[@yadfaruq5294]

the best information thank u teacher for the hard work 👍👍👍👌👌👌👌👏👏👏👏👏👏😊

[@wuyangzhuge5685]

This video really helps me alot!!! love it!! This method really heps the beginer to somehow load a user defined function as input, while the udf model always crashed when it didn't find nmake or your enviroment is wrong. Could you please do another video about the user defined function in coupling systems? THX a lot

[@AnsysTutor]

Thank you Wuyang 🙏 will try to make the tutorial.

[@vrajasenan]

Thanks a ton. Your videos are great. I was wondering if you could make one on changing boundary type dynamically? Essentially change an inlet from pressure inlet to a wall and back. I know this can be done manually but im looking to automate the process. Thanks again!

[@AnsysTutor]

Will try to make a tutorial on that. It can also be done using the procedure as shown in this tutorial, for that you need to arrange the velocity table as per that.

[@vrajasenan]

@@AnsysTutor hi I'm actually replicating my experimental setup which uses pressure control in a microfluidic system connected to pinch valves to control multiphase flows. The need for a pressure control system is due to the need of increased stability of the multiphase system. This poses a problem while simulating with pressure inlet conditions because if the pressure gradient at the droplet formation point reverses direction the flow reverses given the fixed pressure inlet condition. Hence by using an inlet condition that changes to a wall I can accurately model the pinch valve. My main issue is that I have to manually stop fluent to change the boundary type. I've seen forums that talk about creating a scheme file to automate boundary type changes but I'm not completely sure of how to execute this. Thanks a lot for the help. I'm fairly new to to fluent but your videos have been so easy to follow. I've used comsol for many years and recently switched to fluent.

[@kesselle]

@@AnsysTutor can you automate from steady to transient during a simulation?

[@FreitasFilho84]

Perfect!! Very good!

[@AnsysTutor]

Thank you 🙂🙂🙂

[@siavashbozorgchami2216]

Really good! Thanks!

[@AnsysTutor]

Most welcome 🙂🙂🙂

[@sivanaresh8402]

Thanks Ansys Tutor. This video is really helpful. And I’ve a request from my side. I’ve seen you doing conjugate heat transfer (from solid to fluid). Could you please also make a video on conjugate heat transfer from fluid (air at 1000K) to solid (at 295K)? Thank you in advance.

[@AnsysTutor]

That can be done similarly, only you need to have a hot air at the inlet.

[@sivanaresh8402]

@@AnsysTutor what about the boundary condition? I did the simulation but I doubt the results. Could you please write me an email. I’d like to have an opinion from you. I’ll share my simulation files. My email: [e-mail]

[@osmangarg8821]

It is a great method. However I have a question. In data table, you wrote 1 on command row for defining periodicity. Was this periodicity written for defining symmetrical boundary conditions or geometrical symmetrically?

[@zilongzhao2517]

This is just perfect!!

[@AnsysTutor]

Thank you.

[@RanjeetBhosale-od4pw]

I want to give mass flow rate at outlet what should I do, can I put mass flow rate insted of velocity

[@AnsysTutor]

You want to put the mass flow rate as transient table data or single value data?

[@RanjeetBhosale-od4pw]

@@AnsysTutor i tried but it is unable to read

[@RanjeetBhosale-od4pw]

@@AnsysTutor single value data?

[@mounarahal256]

hello, can i use different time steps in the transient table or should i use the same time step? thanks

[@AnsysTutor]

Whatever data you put in the time table it should be of smaller time steps, otherwise you would not get better result.

[@arunissac2753]

Thank you

[@AnsysTutor]

Most welcome.

[@oz9330]

Hello thank you man it's very clear! one question though how can you add two tables? for example one for inlet and another for outlet iam working on an unsteady flow and need to set both inlet and outlet parameters thank!

[@mehtabkhan8033]

This is very handy. Thanks for the nice work. However, I would like to know if there is a simple way of updating the same transient file aft a specific time; like every 10 mins of my simulation I would like to have a new transient profile for the velocity inlet.

[@AnsysTutor]

You need to write UDF for that.

[@vikassingh4577]

Great tutorial.. I have followed all the mentioned steps. However, the flow time VS facet average velocity magnitude plot is showing me constant results. In other words the velocity is not changing with time..please help

[@AnsysTutor]

please check again. are you getting any reverse flow warning. and what about the mesh is it same as the tutorial?

[@vikassingh4577]

@@AnsysTutor Hi, thanks for the prompt response. My mesh is not same, I have different domain with unstructured meshing on it. I don't have reverse flow also. I have initially put different values in the table (as per my requirements). But as this was not working I have exactly followed the values of your table, still I am having a flat line on chart.

[@abderrahmanmellalou359]

hello please can we do the same in the case of solar load model? also taking in consideration the incident ray vector? and thank you

[@AnsysTutor]

Though I had never worked with that, but I guess it can be done.

[@jildoudejong2821]

Great, thank you! What happens with the in-between points, for example between t=0 and t=1? Does the value get linearly interpolated?

[@AnsysTutor]

Yes.

[@syauqinurrachman3364]

how if i want to change the transient table data? how to replace previous table?

[@AnsysTutor]

You can simply make another file and replace it at the previous data location or edit the previous data.

[@nakulaalva9989]

How to decide values of timestep size, no of timesteps and max iterations/timestep?

[@ruizeng3076]

great!!!

[@AnsysTutor]

Thank you.

[@europa3233]

Can I use tables for mass flow rate, because writing a udf is too hard

[@AnsysTutor]

Yes, it the same procedure.

[@europa3233]

@@AnsysTutor I've attempted it but something failed. Is there a specific syntax for mass flow inlet? Also if I want the boundary to be on until a certain time do I use periodic =1 or 0 Thanks for your time.

[@ananthavishnumheman3067]

It was really useful....can you please tell me how to simulate a periodic rotating cylinder. That is, a rotating cylinder with continuous reverse in direction of rotation. I am not able to find an option in fluent to change the constant value of angular velocity to a periodically changing value. Please help.

[@AnsysTutor]

have you tried the way as described in this Tutorial video? >please try and check if it works.

[@ananthavishnumheman3067]

@@AnsysTutor Thanks for your kind reply.....i tried the above method for a wall with transient linear velocity..it works well....but I am not able to simulate a wall with transient angular velocity.....which means a wall having angular velocity 3 rad/s (example) for first five seconds and the same wall is having angular velocity -2 rad/ sec for the next five seconds.....and this motion periodically repeats.....can you please help to do the same....

[@user-Akchi]

Good! It's equivalent of journal files. as I understand it?

[@AnsysTutor]

yes its is similar , but with a less coding skill like in script files.

[@0alcoholism2]

Hi, Thanks alot for the video. I wanted to ask that my input parameter gives the time in milliseconds and since I have high velocities, it would be much accurate if I could give the time in milliseconds instead of seconds. Is that possible to do it in Ansys? or do I always have to use seconds? Also, can I do the same method for varying the fluid density and outlet pressure?

[@AnsysTutor]

Yes, you can put time in milliseconds.

[@AnsysTutor]

As the default unit is in second the value you enter in time column is taken as second.

[@AnsysTutor]

Yes you can use the same for other parameters too.

[@0alcoholism2]

@@AnsysTutor Hi, thanks a lot for your reply, but I'm not able to see my transient table as a type of input when i want to change the type of density of my fluid from constant. Can you please help me a little with that? It works perfectly for my inlet velocity and outlet pressure though.

[@0alcoholism2]

@@AnsysTutor Would it work if i interpreted the transient table for fluid density as an UDF? If not, how can I take my outlet pressure as an input in an UDF

[@vineethragipati5219]

Thanks a lot for such a good video...Can you pls help me with this error...I had done exactly as you have mentioned and am getting an error as "Error: get_time_interpolated_value: profile field \"Tab Time\" does not exist"...can u pls help me in this...

[@vineethragipati5219]

"Tab" is the function name which I had provided...

[@AnsysTutor]

Do not provide space inbetween. "Tab time " it might create some error. check once if it works.

[@vineethragipati5219]

@@AnsysTutor sir, Tab is the name which I had given instead of ansystutor in ur video...it's the frst line of the text file...I haven't given any space...Thank You for replying...

[@vineethragipati5219]

In the boundary condition drop down menu it shows as "Tab time" ...in ur case as "ansystutor time"...or velocity or any other parameter...I have one more doubt...Can we give uppercase alphabets here?...

[@AmineAmine-kd1tq]

I had the same problem, did you fix it. Please help me.

[@Vibhor-Mathur0905]

Hey... I did the same ss instructed. But once I'm selecting the file, it is showing 'Data not complete'.

[@AnsysTutor]

You might have space in the text file name or in the data table anything missing or any extra space, please check.

[@abhishekgupta1607]

I have few time step with negative velocity. How can i implement this?

[@AnsysTutor]

try with the same table with negative velocity values, I have never tried but should should try once if it works.

[@abhishekgupta1607]

@@AnsysTutor I have tried that also but velocity is not going below 0. Fluent calculates velocity as there is no negative sign.

[@jesvinabraham7448]

Sir, is it okay if we paste the values from excel sheet?

[@AnsysTutor]

Yes, its ok. Try to avoid any void cell or space.

[@jesvinabraham7448]

@@AnsysTutor Thank you sir. It worked🙂

[@daminisingh6490]

hello I am trying to incorporate a transient boundary condition in fluent. i am doing thr same as u showed in your video, i am following all your step. I saved table in the text format and i am trying to read it into fluent by using the read-transient-table command. I have saved the file in the same directory where the project saved. However, I keep getting error of file is not found.

[@AnsysTutor]

Once check of your file name has any space in between words, if it has then replace it with any special character. And also, If your file name has first letter in uppercase then it might cause such error. Once try and comment if this problem still persists.

[@daminisingh6490]

@@AnsysTutor Thankyou so much, my error has resolve. The error was coming because of space in profile name.

[@farkhandaazmi313]

@@AnsysTutor i have got the same problem and I tried by keeping the file name without any space in between and file name is in lowercase, still I get the error that file is not found. Please help!

[@farkhandaazmi313]

well! It finally worked. The only issue was the file location. I cut and pasted the text file in: dp0 > FLTG > Fluent. Thank you very much for sharing an easier way for transient data import!

[@VrindaKrishnanvk]

I got error data not complete

[@AnsysTutor]

Check if you any space or special charaters in the data table text file.

[@davidabaidoo4195]

thank you teacher, its a very good video. Can you please show me how i can set boundary conditions at different locations(different velocities ie X=1m, Vel = 4m/s; x=2m, Vel=1.5m/s; x=3m,Vel=1m/s) along the length of a horizontal pipe. i tried to use the concept of this tutorial but it didn't work. Thank you

[@AnsysTutor]

i think you need an UDF for this.

[@poppyoneill6293]

When doing calculate, I get the following error: Error: This is a post-processing only executable Error Object: #f

[@AnsysTutor]

Its a cfd post error. Just cancel it its not a major issue.

[@alexcanovasixifra1614]

I CANOT get ansys to read my file :-(

[@AnsysTutor]

Follow the tutorial properly. Dont forget to write the .txt extension while calling the file.

[@alexcanovasixifra1614]

@@AnsysTutor I finally did a write-bc, an rewrited as wanted, and then ansys allowed me to do it