The wind stress coefficient is based on one given by Van Dom (1953) and
others which is assumed to be a function of wind speed; thus,
k = Kx ,
for W < Wc
(3-58)
/ wcv
k = K + K
1-—
for W > W
(3-59)
1
2 \
W /
c
where the constants Kj and K2 are usually taken to be 1.1 x 10-6 and
2.5 x 10“6, respectively. Wc is a critical wind speed taken as 14 knots
(16 miles per hour).
Introducing the bottom and free-surface stress relations into
Equations 3-53 and 3-54 gives
— = — [fV+kW2 cosfl]
(3-60)
9x
gD
3 V
kV2
— = kW2 sin 0 — ——
(3-61)
an estimate of the amount of setup that can be attributed to the onshore
effects. The setup attributed to longshore effects can be obtained by
rewriting Equation 3-60 in the following two-component form:
kW2 cos 6
dx
gD
5
dx
gD
(3-62)
(3-63)
total setup along the x-axis is the sum of the two components or,
as
ÔSX
asv
— = --- + —L
3x
9x
dx
(3-64)
„.1„„ Jhecfln !'dcfference numerical solution of the reduced équations,
dnïu r^r.f- a”d -SV, !re evaluated « Points spaced Ax apart along a
etu, for îheT aX'S the traverse
The values of S, the total
be ween two noln^eraî ’ T e regarded as being the water level midway
« a time / T ?10n\the traverse Une, midway between x and x ♦ «
betieen Link w< 1°ngahore ''01ume transport of water V is also evaluated
at the points 'x and
h*6 C°ri°lis Paraa>eter are supplied
x. The subscripts and superscripts i and n
3-104