ERDC/CHL CETN-IV-26
June 2000
Prototype Parameters:
= 245 m
Inlet width: Wp
≈ 14 m
Maximum depth: (hmax)p
Median grain size: (de)p
= 0.61 mm (quartz)
≈ 1.8 m/s (depth-averaged)
Maximum velocity: V p
≈ 2,400 m3/s
Maximum discharge: (Qmax)p
The inlet width and maximum depth are geometric parameters that scale directly with the length
scale, e.g.,:
b
g
Wp
Wp
245 m
= N L = 75 or Wm =
=
= 3.3 m 10.7 ft
75
75
Wm
The grain-size diameter scale ratio is given as:
bde g p = 0.61mm = 4.7
bde gm 0.13 mm
=
N de
which is needed to determine the required velocity scale from Equation 2, i.e.,:
b g3/8 b75g1/8 = 3.07
N v = N d /8 N 1/8 = 4.7
3
L
e
The maximum model velocity comes directly from the velocity scale as:
b
g
Vp
V p 1.8 m s
= 3.07 or V m ≈
≈
≈ 0.59 m s 1.9 ft s
3.07
3.07
Vm
Recognizing that the discharge scale is simply the velocity scale multiplied by the area scale,
i.e.,:
b g2 = 17,270
2
N Q = NV N A = NV N L = 3.07 75
the maximum model discharge is obtained as:
e
j
2,400 m3 s
Qp
Qp
≈ 0.14 m3 s 4.9 ft 3 s
= 17,270 or Qm ≈
≈
17,270
17,270
Qm
In summary, the movable-bed model of Shinnecock Inlet should have the following
characteristics. These are reasonable parameters well within laboratory capabilities.
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