In some cases, the automatically generated initial guess for the velocity magnitude and/or direction may not be appropriate. For example, for large domains with small, high-speed inlets, the initial guess for velocity may be too high. You can optionally enforce a velocity scale (which is essentially the velocity magnitude used throughout the domain). The calculated velocity directions are unchanged. In particular, applying this velocity scale to zero direction vectors will still yield a zero velocity vector. For details, see Automatic Values.

A zero velocity field (that is, a quiescent velocity field) results if the velocity scale is set to 0.