{"id":164605,"date":"2023-03-17T08:58:09","date_gmt":"2023-03-17T08:58:09","guid":{"rendered":"\/knowledge\/forums\/topic\/when-creating-an-animation-of-a-rotating-device-with-blades-eg-impeller-the-device-appears-to-rotate-backwards-why\/"},"modified":"2023-07-31T12:25:54","modified_gmt":"2023-07-31T12:25:54","slug":"when-creating-an-animation-of-a-rotating-device-with-blades-eg-impeller-the-device-appears-to-rotate-backwards-why","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/when-creating-an-animation-of-a-rotating-device-with-blades-eg-impeller-the-device-appears-to-rotate-backwards-why\/","title":{"rendered":"When creating an animation of a rotating device with blades (eg impeller), the device appears to rotate backwards. Why?"},"content":{"rendered":"

First, ensure that the rotation is specified correctly in the simulation setup. If this has been confirmed, it’s likely that the apparent backwards rotation is due to an optical illusion called the “wagon wheel effect”. To check this, in CFD-Post or EnSight, place a point (CFD-Post) or probe (EnSight) on a node on the rotor and generate the simulation. If the point moves in the correct direction, but the rotor itself appears to move backwards, then the wagon wheel effect is present. To avoid, this you can do the following: – in CFD-Post In the Animation settings, open the Advanced Frame Selection Controls, and increase the Specified Timestep Interval. If the interval is chosen such that the blade position on the n+1 timestep is just past a blade position at timestep n (less than half of the blade pitch past), then it will appear to rotate the right way. – in EnSight Open the Solution Time settings (… button in Time panel). Change the Scale Type to Continuous and adjust the Step Increment. If the Step Increment is chosen such that the blade position on the n+1 timestep is just past a blade position at timestep n (less than half of the blade pitch past), then it will appear to rotate the right way.<\/p>\n","protected":false},"template":"","class_list":["post-164605","topic","type-topic","status-publish","hentry","topic-tag-2021-r2","topic-tag-animations","topic-tag-cfd-post","topic-tag-fluid-dynamics","topic-tag-post-processing","topic-tag-rotating-flow"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t