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Coastal Engineering: Theory and Practice
m = beach slope, 7 = breaker index = Hb/db, N = dimensionless constant,
Cf = current friction factor.
Pi = (-3/4) +[(9/16)+ (1/Pe)]1/2
e = 1/(1 + 0.37572) and
P2 = (-3/4)- |(9/16) + (1/Pe)]1/2
The parameter P is non-dimensional and represents the relative importance
of horizontal mixing.
Solution
Solving for T = 11 sec
Firstly find the breaking point using the équation below:
Maximum breaker height may also be approximated using criteria
7=(tft/dt) = 6-a(ffi,M2)
where
a = 4.46 g (1 - e~19m),
b = [1.56/(1 + e“19,5rn)],
m = 1/100,T = llandHb = 1.5
For the présent problem substituting the variables we get
a = 7.57, b = 0.855
7 = Hb/db = 0.855 - 7.57 x [1.5/(9.81 x 112)] = 0.846
db = 1.5/0.846 = 1.77 m
Hence
db = 1.77 at a distance, 1.77 x 100 = 177.3 m
e = 0.788, e2 = 0.621 and fc = 0.002
u0 = (5tt/16/c) 7( = [(5 x 7T x 0.846)/(16 x 0.002)] (0.621)(9.81 x 1.77)1/2 (1/100) sin6
= 1.135 m/s