CMS-Wave:Transmission

Wave Transmission over structures

(Summarized from from JCR SI 59 pp7-14)

Impermeable Structures

Low-crested or submerged impermeable structures

Wave transmission is exhibited by fall of the overtopping water mass. The ratio of structure crest elevation to incident wave height is a key parameter governing the wave transmission. CMS-Wave calculates the transmission coefficient $K_t$, defined as the transmitted wave height divided by the incident wave height, based on the simple expression (Goda, 2000):

$K_t=0.3(1.5-\frac{h_c}{H_i})\text{, for }0\le \frac{h_c}{H_i}\le 1.25$

(Eq. 10)

Composite breakwater protected by a mound of armor units at its front

$K_t$ is calculated as

$K_t=0.3(1.1-\frac{h_c}{H_i})\text{, for }0\le \frac{h_c}{H_i}\le 0.75$

(Eq. 11)

where:
$h_c$ is the crest elevation of the breakwater above the still water level
$H_i$ is the incident wave height.

Permeable Structures

For permeable structures, wave transmission is calculated using modifications to d'Angremond et al (1996) formula.

Permeable rubble-mound breakwaters

$K_t$ is calculated using as:

$K_t=0.64[1-\exp (-\frac{\xi }{2})]{\left(\frac{B}{H_i}\right)}^{-0.31}-0.4\frac{h_c}{H_i}\text{, for }\mathrm{B}<10H_i$

(Eq. 12)