3. Sédiment Transport
81
Problem II
Calculate the value of Pis parameter for the following wave conditions using
any four formulae for breaking wave characteristics:
Hq — 1 m, cto = 39°, m = 1/50 and T = 10 s.
m = 0.02
Lo = 1.56 T2 = 1.56 x 102 = 156 m
Co = Lq/T = 15.6 m/s
Table 3.6. Breaking wave heights and other parameters from different formulae.
SI.
No
Author
Formulae
Hb
(m)
dh
(m)
Lb
(m)
c9
(m/s) sin2a{,
Pis
(J/m-s)
1 Komar and
Gaughan
[1972]
0.56Ho
(Ho/Lo)-0'2
1.537 1.970 43.4 4.34 0.3446 2220.36
2 Sunamara and
Horikawa
[1974]
H0m°-2
(Ho/Lo)-0,25
1.616 2.072 44.37 4.44 0.3524 2567.86
3 Ogawa and
Shuto [1984]
O.68Hom0,09
(Ho/Lo)-°-25
1.69 2.167 45.23 4.52 0.3585 2908.52
4 Smith and
Kraus [1990]
Ho (0.34+ 2.47m)
{Ho/Lo')-°-3+o-8Sm
1.621 2.078 44.5 4.45 0.3532 2595.48
Problem III
A breaking wave of 1.5 m height approaches a beach slope of 1:100, at an
angle 6° to the beach. Calculate and compare the longshore current profile
for wave approaching with 11 sec and 6 sec by assuming that the friction
factor may be taken as 0.002 and the mixing parameter N as 0.011.
Where
A = [1/(1-2.5P)](P/0.4)
Si = «P2 - 1)/(P1 - w
b2 = «A - D/(Pi - p2)M
P = (îrmA’/yC'y)
e = 1/(1 + 0.37572)