Gravity Waves and Finite Turbulent Flow Fields 



0.5 

 0.4 



Vw 03 



^ 0.2 



0.1 







GRID WIDTH = 11.50*1 DRAFT = 20'; MESH SI2E = 5.4 

 (GRID TOWED IN 12 FT WIDE TANK) 

 VELOCITY PROBE AT lO" DRAFT 

 Vvv = WAKE VELOCITY ; V=GRID VELOCITY 



TANK 

 WALL 



10 FT AFT OF GRID 



Vw 

 V 



0.5 

 0.4 

 03 

 0.2 

 0.1 



»- 

 



1 



TANK 

 WALL 



20 FT AFT OF GRID 



12 3 4 5 



y= LATERAL DISTANCE FROM GRID ({. . FEET 



Fig. 2 Longitudinal Velocity Distribution in Grid Wake 



Wave Height Probes : Wave heights were measured by re- 

 sistance type wave wires penetrating through the water surface. 

 The position of the wave wires relative to the grid are shown in 

 Fig, 1. It is seen that wave wires moving with the grid were 

 located 1 2 f t ahead of and along the grid centerlinej 13.25 ft and 

 16. 50 ft aft of and along the grid centerline; and one located 13,25 ft 

 aft and 4 ft transverse to the grid centerline. The wave wires 13.25 ft 

 and 16. 50 ft eift of the grid were used to obtain a nneasure of the ap- 

 parent wave length in the turbulence field while the pair of wires 

 4 ft apart in the transverse plane 13.25 ft aft of the grid were used 

 to measure any deformation of the wave crest line as it progressed 

 through the turbulence. A stationary wave wire was located 60 ft 

 forward of the wavemaker and was used to examine the regularity of 

 the amplitude and period of the generated incident wave. 



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