By default, the tank’s cylindrical part is positioned with its base at z = 0. This implies that the dished and cone bottom sections are positioned just below the
xy-plane. If you define a flat bottom tank with a fillet radius on the lower cylinder edge, then also the fillet section created is placed just below the
xy-plane. If you specify a zero fillet radius for a flat bottom tank, then the base of the tank is positioned in the
xy-plane, that is, at
z = 0.
The impeller shaft’s lowest part is also by default positioned at z = 0. You can change the position, length, and diameter of the impeller shaft. However, the impeller shaft is always placed in the middle of the tank perpendicular to the
xy-plane.