SHIP
SURFACE CURRENTS DUE TO VORTICES
m (TYPICALLY 1 - 100 cm/s)
NET REARNARD VELOCITY
(TYPICALLY 1 - 10 cm/s)
DARK AREA——7]
OCCASIONAL BRIGHT LINES —»-
€ eR en.
Ae
HULL VORTICES
(NOT TO SCALE)
Figure 9. Diagram of Turbulent Wake Structure Showing Possible Role of
Vortices and Net Rearward Velocity Within Turbulent Region
(after Swanson, 1984)
~WIND (~ m/s)
Q. 4
I
I
!
in
|
— ij!
m -271 |. i \
ea | \
x \
= — 4
Suny —
um —
z I
ul I
— —-S41 +7 \ |
= \
uJ \
2 |
=
= LA PES MODEL
À I
Cs spans J ACTUAL
= FI
M
||
|
li
-10.82 + + + + +- + + + + + + + + + + 4
a. 33.52 107.64 161.46 215.28 269.1 322.92 376.74 430.56
A
A DISTANCE (METERS)
Figure 10. Graphical Comparison of Predicted Radar Backscatter Variation
Based on Vortex Model (dashed) and Actual Backscatter
Measurements (solid)
421