ERDC/CHL CHETN-I-69
March 2005
(2) Depth, d. When the dialog opens, the depth is set to 0.0 by default. The depth is forced to be
a number greater than or equal to 0.0. When the user changes the depth, the calculated wave
parameters are updated.
(3) Average wave height, H. When the dialog opens, the average wave height toggle box is not
checked by default. The average wave height itself is set to 0.0 by default. When the average wave
height toggle box is off, then the edit field and unit's text are disabled. When it is on, then the edit
field and unit's text are enabled. The average wave height is forced to be a number greater than or
equal to 0.0. When the average wave height toggle is changed and when the average wave height
value is changed, the calculated wave parameters are updated.
Wave parameters computed by the calculator include:
(1) Wavelength, L. The wavelength will be calculated using the transitional wavelength equa-
tion. Wavelength has units of meters.
(2) Wave number, k. The wave number is calculated from wave number as k = 2π / L . If the
wavelength is 0.0, the spreadsheet cell for the wave number value is left blank. The wave number
has units of 1/m.
(3) Celerity, C. The wave celerity is calculated from wavelength and wave period as C = L / T .
If the period is 0.0, the spreadsheet cell for the celerity value is left blank. The celerity has units of
m/s.
(4) Group velocity, Cg. The group velocity is calculated using the following equation: Cg = nC
⎡
⎤
4π h
1⎢
⎥
⎛ 4π h ⎞
L
where n = ⎢1 +
⎥ . If the wavelength is 0.0 or if sinh ⎜
⎟ is 0.0, then the spreadsheet
⎛ 4π h ⎞ ⎥
2⎢
L ⎠
⎝
sinh ⎜
⎟⎥
⎢
⎝ L ⎠⎦
⎣
cell for the group velocity is left blank. The group velocity has units of m/s.
2π
(5) Angular velocity, ω. The angular velocity is defined as: ω =
. If the period is 0, then the
T
spreadsheet cell for the angular velocity value is left blank. The angular velocity has units of rad/s.
(6) Maximum wave height (or breaking wave height). The maximum wave height is calculated
using the following relationship: H max = 1.86H1/ 3 where H1/ 3 = 1.416H ave . However, the maximum
wave height cannot exceed 0.78h. If the maximum wave height exceeds 0.78h, then the breaking
wave height is reported as Hbreak = 0.78h . The maximum wave height (breaking wave height) is only
calculated when the average wave height toggle is on. The maximum wave height (breaking wave
height) has units of meters.
(7) Steepness. The steepness is calculated from the relationship: steepness = H max / L . If the
wavelength is 0, then the spreadsheet cell of the steepness value is left blank. The steepness is only
calculated when the average wave height toggle is on. The steepness has no units (m/m).
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