## Fluids

#### Post processing: Plotting chart on temperature vs angle (theta=0to360) around a circular wall.

• gishnutr
Subscriber

Hi All,

In CFD Post or Fluent, i have to plot a graph on temperature vs angular distance along a circle which is drawn near  a cylinder wall.

The cylinder wall is not centered at origin. In CFD Post i could draw a circle around the cylinder by polyline (polyline creation:boundary intersection method==> boundary list "cylinder" ==> intersect with "cylinder" and scaling x,y,z to 1.2)  method.

Is there any other way to do this? If not, any other soft wares?

Thank you

• raul.raghav
Subscriber

I assisted another member of the forum with something very similar. You can find the discussion here: How to Create Line Location along Elbow Centerline?

The point from that post that's relevant to your case is the fact that you want to create a graph of Temp (K) vs theta (deg). I mentioned in the post that you would need a session file to create "n" number of points along the wall and then you can create another session file to extract the temperature data at each angle. All the information is available on the other post. If you're still a little confused about the session files, share the workbench archive file with me and I'll show you the steps to extract the data, and plot the graph.

• gishnutr
Subscriber

Hi Raul,

I tried your options, but i'm little confused with those methods. Its because i'm just a beginner in this field , most of the methods are entirely new to me.

But i have plotted the chart with temperature vs the curve length of polyline. I have attached pictures below.

Here the chart was plotted on temperature vs curve length of polyline. In the graph the maximum temperature shown is below 314k. but when i used the probe tool to find the temperature at a point on the polyline i got reading 322k. This value is not even shown int the chart. Is my method correct? I was thinking about converting the curve length to 360 degree.

Thank you

Edits: When i plot  chart AT the cylinder wall (not at a small radial distance) i got the same curve. So   the poly-line circle i created is giving me same result as that of the wall surface.

• raul.raghav
Subscriber

I was a beginner and still consider myself to be one, so no issues at all . It would be really difficult to tell how and what values CFD-Post is showing without looking to the setup (in CFD-Post). Would you be able to attach your (.res file and the CFD-Post state file) here by zipping it? I would be able to tell you what's going on.

• gishnutr
Subscriber

I have attached the files in above post.

Thank you for helping me to find solution.

• raul.raghav
Subscriber

I tried opening your file and it shows the following error. Could you create a CFD-Post compatible file based on the instructions given here: Exporting to ANSYS CFD-Post

• gishnutr
Subscriber

Raul,

Sorry for late reply. I have attached a new zip file. Please take a look. Hope this works.

Thank you.

• raul.raghav
Subscriber

Attached are the session files which will help you create 361 points around the top cylinder center. Another session file will export the temperature data from each of the 361 points to the Table. You can copy and paste the tabular data into excel or other graphing software to get then plot of Temperature vs theta as shown below. See the attached pictures for reference as to how to edit the session files. The session files can be edited using notepad++ or notepad. If you can't see the option of "Play Session" in CFD-Post, open CFD-Post as a standalone and not from the workbench.

Let us know if you have further trouble understanding any of this.

• gishnutr
Subscriber

Rahul,

Thank you for doing this. I got the session files and i loaded it in CFD post.

I have to do the same with some other dimensions. Will you please guide me through the process of making session files.

Gishnu

• raul.raghav
Subscriber

Session files in CFD-Post are simple to create and they can modified according to your needs. Refer:

As a simple example, say you want to create 100 XY planes along the length of a tube (i.e., along the Z-axis). Creating one XY plane is easy, however, 100 planes is not an easy task, specifically if you want to extract information out of all the generated planes. To simplify this process, you record and save a session file by creating one XY plane. Once the first plane is created, you stop the session file. At this point, you can edit the session file with notepad++ or notepad and add a "for loop" to create 100 planes. You can be really creative about editing the session file and actually achieve a lot of things using this feature.

In your case since, you already have the two session files: (i) to create 361 points in a circular pattern around the top cylinder, and (ii) to extract data out of the 361 points and tabulate it. All you got to do is to edit the session files by changing the "x" and "y" coordinate points for the top cylinder. If you have to create points around the bottom cylinder, change the "xOrigin" and "yOrigin" in the session files as well. The basis for first session file was to create 361 points in a circular pattern centered around the (xOrigin, yOrigin) points. The second session file was straightforward extracting data from the generated points.

• gishnutr
Subscriber

Hi, Raul

This discussion was  really useful. Till this i never knew about session files. Now i have learned to create and edit those files and play with it. Thank you for guiding me through all these steps.