surface-elevation time series. The information required to generate the incident
wave boundary conditions is described as follows:
Wave Synthesis Options
- Synthesize velocity and flux time-histories from parametric information
- Read in measured surface-elevation time series. The input file has to be
in the time series file format described in Appendix D.
Incident Wave Type
- Regular Waves
- Irregular Unidirectional Waves
- Irregular Multidirectional Waves
Regular Waves
Wave Height (m) vertical distance between the wave crest and trough.
The incident wave height should not exceed 75 percent of the breaking
limit given by the Miche criterion as Hbreak/L = 0.14 tanh kh. When the
wave height exceeds 25 percent of the breaking limit, nonlinear effects
become important and the time-histories are synthesized using the
Boussinesq-Fourier theory discussed in Appendix A.
Wave Period (s) time interval between successive wave crests. The
incident wave period has to be greater than the limit imposed by the
dispersive properties of the Boussinesq equations, i.e., the wavelength
calculated from the linear dispersion relation (Equation 10) using the
wave period and maximum water depth has to be greater than twice the
water depth (L > 2hmax).
Wave Direction (deg) This is the direction the waves propagate into
the computational domain from, and is defined in a clockwise manner
from the northern boundary of the grid as shown in Figure 6. For
example, waves propagating into the domain normal to the western
boundary would have a direction of 270 deg. The incident wave
direction also has to be within 85 deg of the normal to the wave
generation boundary.
Number of Wave Cycles This determines the time period over which
output parameters such as the significant wave height and mean veloci-
ties are calculated after steady-state conditions have been established in
the computational domain. The recommended range is from 10 to 50.
Irregular Waves
Type of Wave Spectrum
JONSWAP
Bretschneider
Pierson-Moskowitz
TMA
Ochi-Hubble
32
Chapter 4 Setting Up and Running BOUSS-2D
Previous Page
