Wave-Induced Eddies and "Lift" Forces on Circular Cylinders 



Direction of Wove Propagation 



■Still Water Level, C Surface Trough ^ Wafer Direction of Wave Height, 



SWL Wo,er Particle Particle Water Particle H 



Orbit Motion 



Water Depth, h 



h/L — relative depth 

 J /A = proportional depth 



Note: Vertical scale and 

 particle orbits 

 exaggerated 



Wave Crest, at time y = 0.722 

 ■ *- 



*■ Front of wove passing through 

 h SWL, T = 0.528 



SWL 



Water particle 



at -f =0.528^ I > 



Water Particle 

 Orbit for: 



H = 6 feet 



T - 10 seconds 



h = 40 feet 



y - -7 feet 



GRAPHICAL DESCRIPTION 

 OF TERMS 



/Water particle 

 at ± = 0.722 



. • l f~T * * • /N. Particle Motion 



v ; '•> 



L- 37r! 

 T" 2 



y = - 7 feet 



- f = 0, 2TT 



Mean position of water particle 



_ _ _ d v 



r, -n, r, -^ 



Coordinate System 



Figure 4. Water particle orbit due to waves (From Wiegel, 1964) 



767 



