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Who can tell me is there sth wrong in my settings of frame motion model?

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Old   May 11, 2020, 04:18
Default Who can tell me is there sth wrong in my settings of frame motion model?
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I did a centrifugal pump's simulation which was shown in fig1(the vilocity streamlines in CFD-post),but I don't know why the vilocity streamlines looks like wrong(blue circle).

The point O's coordinate is(0,0).

Is there sth wrong in my settings of frame motion model?
Maybe I should get the "R" bigger?


I attached the cas file on my thread.Thank you in advance.
Attached Images
File Type: jpg frame motion model.jpg (151.5 KB, 10 views)
File Type: jpg fig.jpg (48.6 KB, 6 views)
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File Type: zip pump.zip (187.9 KB, 1 views)
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Old   May 11, 2020, 04:27
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Or I should use sliding mesh model to do this simulation:

https://ansyshelp.ansys.com/account/..._slide_ex.html
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Old   May 11, 2020, 11:04
Default Frame of Reference
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Most likely you are plotting the velocity profile using rotating frame of reference. In CFDPost, you need to select stationary reference frame.
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Old   May 11, 2020, 22:37
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Thank you!
I saw the pathlines in fluent,almost like the CFD-post's steamlines.(fig1)
And would you please tell me how to select stationary reference frame in CFD-post? I didn't found the options in CFD-post(fig2, fig3)

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Most likely you are plotting the velocity profile using rotating frame of reference. In CFDPost, you need to select stationary reference frame.
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File Type: jpg fluent pathlines.jpg (127.3 KB, 3 views)
File Type: jpg coordinate frame.jpg (111.3 KB, 3 views)
File Type: jpg stream lines.jpg (47.1 KB, 2 views)
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Old   May 11, 2020, 23:22
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and the vilocity vector map is quite continuous.
Maybe I didn't understand what pathlines means?or the pathlines are not suitable for frame motion model?

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Most likely you are plotting the velocity profile using rotating frame of reference. In CFDPost, you need to select stationary reference frame.
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Old   May 11, 2020, 23:40
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and the vilocity vector map is quite continuous.
Maybe I didn't understand what pathlines means?or the pathlines are not suitable for frame motion model?

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Most likely you are plotting the velocity profile using rotating frame of reference. In CFDPost, you need to select stationary reference frame.
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File Type: jpg vilocity vector map.jpg (84.2 KB, 2 views)
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Old   May 12, 2020, 07:32
Default Pathlines
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Pathlines are particle tracks with particles being massless, implying, pathlines show paths taken by the continuous fluid.
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Old   May 12, 2020, 21:04
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I still don't know why the pathlines have big turn when they cross the interface, and what should I do if I want improve it....

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Pathlines are particle tracks with particles being massless, implying, pathlines show paths taken by the continuous fluid.
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Old   May 13, 2020, 09:02
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Are you plotting the pathlines or velocity contour using stationary frame or rotating frame?
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Old   May 13, 2020, 20:53
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Sorry that I don't know how to plot it using stationary frame or rotating frame ,neigth in fluent nor in CFD-post.Would you please tell me how to plot it that way?

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Are you plotting the pathlines or velocity contour using stationary frame or rotating frame?
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Old   May 14, 2020, 07:42
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There are two variables listed as Velocity in CFDPost, namely, Velocity and Velocity in Stn Frame, i.e., Velocity in stationary or inertial frame. Default is Velocity and not Velocity in Stn Frame. But we are not used to looking at the flow from rotating frame; it looks strange. So, choose Velocity in Stn Frame and then display.
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Old   May 15, 2020, 00:06
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Thank you,Vinerm.
It seems like more reasonable when I change to variable from velocity(1st way) to "velocity in Stn Frame"(2nd way).

The word "Stn" means stationary?So what way show the absolute motion trail? the 1st way or the 2nd way?

And I also wonder why the pathlines are not continuous neither start from Locations nor face centers and so on.

Is there sth that I can do to improve it?

Best Regards!

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There are two variables listed as Velocity in CFDPost, namely, Velocity and Velocity in Stn Frame, i.e., Velocity in stationary or inertial frame. Default is Velocity and not Velocity in Stn Frame. But we are not used to looking at the flow from rotating frame; it looks strange. So, choose Velocity in Stn Frame and then display.
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