7.6. IRREGULAR (2-D) WAVE GENERATION
393
including the types of wavemakers used, methods employed for synthesizing
irregular wave time series realizations, data acquisition capability, method
of analysis, and a list of participating institutions.
It was pointed out by Goda (1985) that irregular wave generators (at
least for the two-dimensional case) are no longer machines of special design;
but instead, rather commonplace machines “... assembled with standard
industrial components”. Goda described the modern-day irregular wave
generator as essentially a signal-following machine; if the driving signal
is sinusoidal, the wavemaker will generate regular waves according to the
first-order theories presented in the previous sections.
Irregular wave conditions which are used for coastal engineering laboratory studies can be separated into four broad categories:
1. Synthesized nondeterministic irregular wave trains that
attempt to match the random characteristics of the natural
sea state only within the bounds of probability.
2. Synthesized partially deterministic irregular wave trains
in which constraints have been placed on one or more of
the random variables.
3. Synthesized deterministic irregular wave trains that control some specific irregular wave characteristic, such as
wave grouping.
4. Actual prototype measurements of wind wave time series scaled for laboratory reproduction.
Laboratory application of each of these irregular wave conditions is discussed in greater detail in the following sections.
The topic of irregular wave generation could, in itself, fill an entire volume if covered in the comprehensive manner it deserves. The following
sections summarize important contributions made by some of the engineers
and scientists who have advanced our understanding of two-dimensional
irregular wave generation. This summary includes an examination of nondeterministic and deterministic irregular wave synthesis methods, a discussion of first-order generation of synthesized and measured irregular wave
time series, and an overview of second-order corrections that can be applied when generating irregular waves. Readers wishing to delve into the
subject more thoroughly should begin by examining the references cited in
the following sections.
As we proceed into a discussion of irregular wave generation, we should
remember that despite advancement in the art of synthesizing and gener
ating irregular sea states in the laboratory...
393
including the types of wavemakers used, methods employed for synthesizing
irregular wave time series realizations, data acquisition capability, method
of analysis, and a list of participating institutions.
It was pointed out by Goda (1985) that irregular wave generators (at
least for the two-dimensional case) are no longer machines of special design;
but instead, rather commonplace machines “... assembled with standard
industrial components”. Goda described the modern-day irregular wave
generator as essentially a signal-following machine; if the driving signal
is sinusoidal, the wavemaker will generate regular waves according to the
first-order theories presented in the previous sections.
Irregular wave conditions which are used for coastal engineering laboratory studies can be separated into four broad categories:
1. Synthesized nondeterministic irregular wave trains that
attempt to match the random characteristics of the natural
sea state only within the bounds of probability.
2. Synthesized partially deterministic irregular wave trains
in which constraints have been placed on one or more of
the random variables.
3. Synthesized deterministic irregular wave trains that control some specific irregular wave characteristic, such as
wave grouping.
4. Actual prototype measurements of wind wave time series scaled for laboratory reproduction.
Laboratory application of each of these irregular wave conditions is discussed in greater detail in the following sections.
The topic of irregular wave generation could, in itself, fill an entire volume if covered in the comprehensive manner it deserves. The following
sections summarize important contributions made by some of the engineers
and scientists who have advanced our understanding of two-dimensional
irregular wave generation. This summary includes an examination of nondeterministic and deterministic irregular wave synthesis methods, a discussion of first-order generation of synthesized and measured irregular wave
time series, and an overview of second-order corrections that can be applied when generating irregular waves. Readers wishing to delve into the
subject more thoroughly should begin by examining the references cited in
the following sections.
As we proceed into a discussion of irregular wave generation, we should
remember that despite advancement in the art of synthesizing and gener
ating irregular sea states in the laboratory...