[vinerm]

What kind of plot do you get when you plot radial coordinate vs. angular coordinate as done the graph you attached. Do note that the radial coordinate is the radius and not the thickness. However, the graph would look same. For thickness, you just need to subtract a constant value equal to radius of the cylinder. That will just shift the whole graph down but it will still look exactly same. Could you post your plot here?

[Prudviraj]

Dear sir , as per suggestions i have tried ....these are the results........


please suggest an alternative if results are not good....

FFF-1-01000.jpg

FFF-1-01000.jpgcylinder.jpg

FFF-1-01000.jpgcylinder.jpginterior surface body.jpg

FFF-1-01000.jpgcylinder.jpginterior surface body.jpgvoulme fraction.jpg

FFF-1-01000.jpgcylinder.jpginterior surface body.jpgvoulme fraction.jpgvof.jpg


sir iam trying in solution tab as per your guidance...... in mesh field only radial coordinate is there....but not angular coordinate (please specify where this option available)......

[vinerm]

2D Fluent may not show angular coordinate, but you can always define it as a custom field function



But why there is no line appearing in the first graph. Did you observe the existence of the iso-surface in mesh display? Does it show the iso-surface as a line passing through the interface? If not, then the iso-surface itself was not created correctly.

[Prudviraj]

Find the uploaded attachments and please elaborate on how to define angular coordinate as variable more detail....


FFF-1-01000.jpg isosurface 0.5 zoom.jpg

FFF-1-01000.jpg isosurface 0.5 .jpg1111.jpg1111.jpg

FFF-1-01000.jpg isosurface 0.5 .jpg1111.jpg1111.jpg2222.jpg

FFF-1-01000.jpg isosurface 0.5 .jpg1111.jpg1111.jpg2222.jpg33.jpg

FFF-1-01000.jpg isosurface 0.5 .jpg

[vinerm]

You can define angular coordinate as the equation that I mentioned earlier. It has to be defined as a custom field function. Furthermore, there will be slight modification to the equation since x and y are based on original coordinate system while you need to define those using coordinate system defined at the center of cylinder.

[Prudviraj]

Originally Posted by vinerm

You can define angular coordinate as the equation that I mentioned earlier. It has to be defined as a custom field function. Furthermore, there will be slight modification to the equation since x and y are based on original coordinate system while you need to define those using coordinate system defined at the center of cylinder.

Sir defined angular coordinate as per your suggested Inverse tan function and product of VOF of water and radial coordinate taken on Y axis......resluts attached.....please suggest if results are not appreciable....



FFF-1-01000.jpg55.jpg

[vinerm]

The equation I mentioned is generic and applicable only if the origin is at (0 0). However, you cylinders are not located at center. So, you have to include that in the equation. If center of the cylinder is located at (0.1 0.5), then equation changes to

[Prudviraj]

Sir i have tried with the product of VOF of water and radial coordinate 0n Y-axis and Inv tan (y-0.0275/x) on X-axis....attached results....please find.....results not appreciable...

FFF-1-01000.jpgaaaaaa.jpg

FFF-1-01000.jpgaaaaaa.jpgbbb.jpg

FFF-1-01000.jpgaaaaaa.jpgbbb.jpgcccc.jpg

[vinerm]

Is it possible for you to share one set of case and data files?

[Prudviraj]

can you please suggest....how to share case files here.....

[vinerm]

This site does not allow such large files to be shared. If the file is lesser than 195 kb, you can share it directly. Else, load it on some third party site, such as, Google Drive.

[Prudviraj]

Dear sir, iam attaching my current CFD geometry with coordinates in meters....Suggest in CFD POST
1)Can you please specify coordinates or methods to draw normal lines over the cylinder for every 10 degrees angle....
2) And please elaborate on how to measure water film thickness at these angles (please refer my second post for your reference).....

FFF.jpg

[vinerm]

If you want to draw lines, then it is easy. Once you have defined the angular coordinate using



then just create iso-surfaces at various angular coordinates, say, 10, 20, etc.

[duri]

Originally Posted by Prudviraj

Dear sir, thanks for your guiding........I have tried using cell zone condition panel and custom field function which is a product of water volume fraction and radial coordinate....Also please tell how to find angular coordinate(option iam not finding)....I have attached (results) reference image....can you please elaborate the next steps to find water film thickness at various angles over the cylinder....

Sometimes it will become painful when we try to exploit some automated options to our needs. If you couldn't figure out vinerm's method fall back to old manual technique.


1. Open an excel sheet and generate the coordinates of lines that you need to extract data. One end of the line is circle (wall) center (x,y) and other end is (r cos theta + x, r sin theta + y). theta is the desired angle and r is some radius that should cover your region of interest eg., 1.5 times of wall radius can do this.


2. In fluent, create the lines using the coordinates one by one.



3. In plot xy, select the line on which you need to plot. Make sure x axis is length of the line and y axis is volume fraction.



4. The x value at which y is close to zero or some cutoff value - wall radius will give you the thickness.


5. If you want more accurate export each line data to file and manually pick the point by plotting and interpolating in excel sheet, use cell values for this.



This is too manual but never fail and I hope you may not get better accuracy than this process.

[Prudviraj]

Dear sir, I have created radial lines in CFDPOST to represent the water volume fraction at various angles....can you please suggest how to find only water film thickness over the cylinder using these lines...Attached images are for your understanding...


Water volume fraction lines with contourvolumw rendering.jpg

Water volume fraction lines with contourvolumw rendering lines.jpg

[duri]

Do step 3 to 5. Plot is available in Results->Plot->XY plot.

Select curve length as x function and y function as volume fraction.

[vinerm]

Each line will give you one point at its angular position. And that point is located at water volume fraction of 0.5 along the length of the line.

So, either you can define an expression that directly reports the radial location of the volume fraction of water 0.5 or you can plot volume fraction of water vs. length of each line (or radial coordinate if you have defined that in CFDPost) and then check value of the radial coordinate or length of line, whichever you used for the Chart, where volume fraction of water is 0.5. Just note down this value for that particular line. Collect all this data and then plot it as a curve in some external plotting tool. Its more work when you do it using lines.

[Prudviraj]

Dear sir, thanks for the response....

[duri]

Sorry I cant reply anymore on this post. You are expecting some magic to happen. If you are plotting on the cylinder wall. Why do you need to spend time to create those lines.

Read carefully, I asked you to plot along those lines your created. This will have step like curve. Each line represents an angle. Extract one value for each line. As you know the angle of each line plot that in excel. You cannot get the second figure from fluent directly.

[Prudviraj]

Dear sir, thanks for your guidelines...