Two types of linear random wave simulation methods are investigated;
viz., (1) Deterministic Spectral Amplitude (DSA) and (2) Nondeterministic
Spectral Amplitude (NSA). These linear simulations are extended to
second-order in a perturbation expansion in the frequency domain by
utilizing a Fast Fourier Transform (FFT).
The nonlinear interaction matrix for waves in shallow-, intermediate-,
and deep-water is also investigated. In shallow water, the
nonlinear interaction matrix is not as well-behaved as it is in intermediate-
and deep-water. The nonlinear interaction matrix is symmetrical
with respect to its frequency indices. The value of this nonlinear
interaction matrix may, therefore, be calculated only from two octants
in the w[subscript m]-w[subscript n] in plane.
Water particle kinematics are computed from the simulated sea surface
by three different Transfer Functions; viz., (1) Linear Frequency
Domain (LFD), (2) Hybrid Frequency Domain (HFD), (3) Ncnlinear Frequency
Domain (NFD). Wave pressure forces on a circular cylindrical pile are
computed at approximately the mid-depth location in the time domain by
the Morrison equation using the Dean and Aagaard coefficients. The
statistics of these wave pressure forces are derived by the moment
generating function approach by assuming that the initial sea surfaces
are linear and Gaussian.
The statistics of these simulated sea surfaces and wave pressure
forces are compared with those recorded during Hurricane Carla (1961)
in the Gulf of Mexico. In the sea surface simulation, the NSA method
gives better agreement with the statistics from the measured sea surfaces
than the DSA method does. However, there is no conclusion that
can be drawn out the wave forces which are simulated from only one
record (WPII No. 6887). / Graduation date: 1981
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/29521 |
| Date | 05 August 1980 |
| Creators | Tuah, Hang |
| Contributors | Hudspeth, Robert Turner |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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