Learning Forum

[fantonelli]

Hi,

According to the user manual if the user specifies the angular velocity (omega), the tangential velocity is computed as omega(r), where r is the radius or radial coordinate. This is fine. However, if the user specifies both the angular velocity and the tangential velocity, Fluent will add the tangential velocity and omega(r) to get the swirl or tangential velocity at each face. This confuses me, can you please clarify.Thank you.

[Rob]

https://ansyshelp.ansys.com/account/Secured?returnurl=/Views/Secured/corp/v242/en/flu_ug/flu_ug_bcs_sec_bound_cond.html%23flu_ug_sec_vinlet_inputs

In other words if you set both you'll get the sum of the values. So tangential velocity + omega.r (angular velocity).   So, I suggest you choose one or the other. 

 

[fantonelli]

Hi Rob, thank you for your reply. Omega is the angular velocity, r is the radial coordinate. Thus, Omega*r = tangential velocity. According to the manual, if the user specifies both the tangential velocity and the angular velocity Fluent will add the tangential velocity and omega(r) which equals to 2*tangential velocity. Please correct me if I am wrong, or there is something wrong with the sentence in the manual. Thank you. Federico.

[Rob]

It won't be 2 x tangential velocity it'll be the sum of omega.r and tangential velocity. There's no reason the two have to be the same.