Fig. 6. Jet angle as a function of ring axis angle. Diagrams indicate jet (
)
and ring axis (ß) angle relative to the X axis as defined for
vortices viewed with a horizontal (top diagram) and a vertical (bottom
diagram) light sheet. Note that is not shown in the vertical sheet
diagram because jet angle relative to the X axis is 0°. Viewed in
the XZ plane (horizontal light-sheet data, circles) at 1.2
FL s-1 (open symbols) or 2.2 FL s-1
(filled symbols), the angle of the jet flow to the X axis was always
less than 90° (upper dotted line), indicating a thrust component to the
jet. Viewed in the XY plane (vertical light-sheet data, squares), jet
orientation was typically slightly negative relative to the X axis
(lower dotted line) over a range of ring axis angles of more than 40°.
FL, fork length.
