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

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 *H*break/*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 *> 2*h*max).

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.

Type of Wave Spectrum

JONSWAP

Bretschneider

Pierson-Moskowitz

TMA

Ochi-Hubble

32

Chapter 4 Setting Up and Running BOUSS-2D

Integrated Publishing, Inc. |