A43 transmission and reflection on an obstacle

A straight obstacle is located within a rectangular basin. The transmission coefficient and the reflection coefficient vary from 0 to 1. Runs A43a through A43f have transmission coefficients 0, 0.2, 0.4, 0.6, 0.8 and 1; the same runs have reflection coefficients 1, 0.8, 0.6, 0.4, 0.2 and 0. Runs A43g through A43l are the same but now there is diffusive reflection and a narrower incident distribution. Graphs of Hs are shown for a point in front of the obstacle as a function of the reflection coefficient, and for a point behind the obstacle as function of the transmission coefficient. Directions are shown by means of 'star' plot in files A41a.plt, A41f.plt, A41g.plt and A41l.plt. Spectra for the two locations are shown in files A43d.plt and A43j.plt

12 cases are considered:

A43a
transmission coefficient 0, reflection coefficient 1
A43b
transmission coefficient 0.2, reflection coefficient 0.8
A43c
transmission coefficient 0.4, reflection coefficient 0.6
A43d
transmission coefficient 0.6, reflection coefficient 0.4
A43e
transmission coefficient 0.8, reflection coefficient0.2
A43f
transmission coefficient 1, reflection coefficient 0
A43g
as A43a, but narrower incident distribution
A43h
as A43b, but narrower incident distribution
A43i
as A43c, but narrower incident distribution
A43j
as A43d, but narrower incident distribution
A43k
as A43e, but narrower incident distribution
A43l
as A43f, but narrower incident distribution

It is noted that due to the absence of phase information in Swan in case of full reflection the wave height in front of the dam is not twice the incoming wave height, but √2 times the incoming wave height.

© 2012: Nico Booij