Converted document
$\newcommand{\lyxlock}{}$
Subsubsection 3.12.2.14: Fluid Velocity Up Subsection 3.12.2: Surface Loads Subsubsection 3.12.2.16: Fluid Resistance

#### 3.12.2.15 Fluid Rotational Velocity

This boundary condition prescribes a rotational velocity on an axisymmetric surface. It is the user's responsibility to ensure that the surface is axisymmetric. The angular velocity is prescribed by specifying the angular speed and the unit vector along the axis of rotation (axis of symmetry) . The user-defined vector is automatically normalized. If the axis does not pass through the origin, the user may specify any point on the axis. The fluid velocity relative to the mesh, , for nodes on the selected surface is evaluated from , where is the shortest vector from the axis to the node and is the nodal position.