[calv]

Hi,

I am trying to simulate a rotating propeller in 3D using sliding mesh in Fluent. I have a rotating (sliding) cylinder which contains the propeller, and the background is just another stationary cylinder. However, when I try to plot the velocity contour of the prop, in CFD-post I chose "velocity in stn frame" (which is what I am supposed to use right?) and got the attached picture. The velocity is the opposite of what it is supposed to be! For some reason the velocity is the highest at the wall boundary of the propeller.

After that, I tried plotting "velocity" contour in CFD-post (attached picture), and then the result makes more sense. But from my understand, "velocity" is the velocity of the frame in motion? I am slightly confused about this. The frame shouldnt be moving right? Only the mesh is moving since im using sliding mesh. So shouldnt "velocity" and "velocity in stn frame" be the same anyway?

The pressure contour seems ok to me so I not sure what's wrong. Could someone help me explain what's happening in the "velocity" and "veloctiy in stn frame" plots.

Any advice would be appreciated.

Thanks,
Calvin

[LUMBERJACK17]

is the same for me to calv, for me are the same, but they show different results indeed