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Shallow Water Effect (2/2) - Coggle Diagram
Shallow Water Effect (2/2)
Landweber
Channels
Hydraulic Radius of channel
\( Rh= \dfrac{Area of Cross section of Channel}{Wetted Perimeter of Channel} \)
When a vessel is in the channel
\( Rh= \dfrac{Area of Cross section of Channel-Area of Cross Section of Hull}{Wetted Perimeter of Channel+Wetted Girth of Hull} \)
Speed loss
function of Hydraulic Radius
Occurs in lower speed than Schilichting
Practical tests
Saunders
Effects of Sinkage
Increases
as speed increases
as depth decreases
greater in bow
Watts
High increase in resistance
Close to Critical speed
Greater increase
Shallower depth
Shallow water first noticed
\( V_k=4,17 \sqrt{h} \)
Critical Speed
\( V_k=6,09\sqrt{h} \)
Schilichting
Not restricted laterally
Speed Loss
\( \dfrac{V_\infty}{\sqrt{gh}} \)
Values of \( \dfrac{V_\infty}{\sqrt{gh}}<0,4 \)
unimportant wavemaking resistance
Function of
Ratio cross sectional area of the hull / depth
For same resistance in deep water
Considers
Same Wavemaking resistance
Shallow and Deep water
Higher frictional in A than in B
B mais próximo de shallow
MENOR VELOC
Lower Depth
Same wavelength generated
lower speed
Same speed
Higher wavelength
