[cfd2020]

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.

[cfd2020]

Or I should use sliding mesh model to do this simulation:

https://ansyshelp.ansys.com/account/..._slide_ex.html

[vinerm]

Most likely you are plotting the velocity profile using rotating frame of reference. In CFDPost, you need to select stationary reference frame.

[cfd2020]

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)

Originally Posted by vinerm

Most likely you are plotting the velocity profile using rotating frame of reference. In CFDPost, you need to select stationary reference frame.

[cfd2020]

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?

Originally Posted by vinerm

Most likely you are plotting the velocity profile using rotating frame of reference. In CFDPost, you need to select stationary reference frame.

[cfd2020]

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?

Originally Posted by vinerm

Most likely you are plotting the velocity profile using rotating frame of reference. In CFDPost, you need to select stationary reference frame.

[vinerm]

Pathlines are particle tracks with particles being massless, implying, pathlines show paths taken by the continuous fluid.

[cfd2020]

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....

Originally Posted by vinerm

Pathlines are particle tracks with particles being massless, implying, pathlines show paths taken by the continuous fluid.

[vinerm]

Are you plotting the pathlines or velocity contour using stationary frame or rotating frame?

[cfd2020]

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?

Originally Posted by vinerm

Are you plotting the pathlines or velocity contour using stationary frame or rotating frame?

[vinerm]

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.

[cfd2020]

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!

Originally Posted by vinerm

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.