A hydraulic power-take-off was designed and built for outboard
engines typical of those used on small boats and Pacific City-type
dories. An associated hydraulic system was developed for use on
these boats to provide power for fishing machinery. The power for
each system was provided by a hydraulic pump direct-drive...
The design of a more efficient waterjet system for excavation of
commercial crab pots buried in ocean sediment was undertaken. The
work resulted in the design of an improved nozzle with performance
that was shown to be significantly better than that of previously used
nozzles. Greater sand penetration and excavation...
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...
The purpose of this study was to ascertain the potential erosion
impacts associated with ship movements in confined waters. The flow
associated with a ship passage can be separated accordingly: (1) the
propeller wake, (2) flow about the hull, and (3) associated waves.
Each of these areas has been analyzed...
The reliability of ocean systems is dependent on organizational factors. It has been shown that low probability / high consequence system failures are overwhelmingly induced by organizational factors. However, no methodology is yet widely accepted for the evaluation of this phenomenon or its accurate quantification. A qualitative complementary approach is...
Caissons are frequently used in the coastal environment for
breakwaters, jetties, seawalls, and piers. Because a satisfactory
analytical solution to a typical caisson installation has not been
developed, design of a caisson-style structure typically is either
based on physical model testing, which is expensive, or the
structure is designed as...
The surf zone exhibits large energetic signals from wave shoaling and subsequent dissipation due to breaking, forcing circulation. The bathymetry responds to the wave and wave-induced circulation with the growth, transport, and destruction of large scale bathymetric features, such as mega ripples and sand bars. There is an obvious fluctuation...
Steep bathymetric anomalies in the beach profile, such as offshore borrow pits, submerged breakwaters, and nearshore canyons can significantly transform the wave climate through the effects of refraction, diffraction, and reflection. When located in the nearshore region the modified wave climate can also substantially change the location of breaking and...
Two types of boundary element models are developed for the interaction of waves with trenches. The first type is for a two-dimensional domain in the horizontal plane and employs the linear long wave approximations. It is shown that appropriate selection of pit geometries leads to a significant reduction in wave...
Anchors resistant to tensile loads are commonly used in civil engineering practice. Anchors in the marine environment are most frequently used for the mooring of vessels. Only recently, with the expansion of the offshore industry, has the need to develop more reliable anchor systems become necessary. Embedded plate anchors are...
This thesis presents the details of a large-scale laboratory experiment to study the runup velocity on a complex 3D bathymetry. The PIV measurements including the instrumental setup, the recording procedure, and the image processing are presented. Tsunami inundation directly affects the coastal population and is one of the most important...
The rip current field resulting from the transformation of surface gravity waves over offshore submarine canyons is studied. Employing a wave transformation model and a wave-induced circulation model over observed bathymetry we find that rip current circulation cells exist with alongshore spacing of O(1OOm) even though the nearshore bathymetry displayed...
Strong tidal currents experienced at Keystone Harbor, WA, have caused navigational hazards and disrupted ferry service in the area. This thesis presents details of the design, construction and implementation of a large scale physical model of Keystone Harbor used to evaluate the effectiveness of proposed jetty design alternatives to improve...
Successful prediction of nearshore sediment migration is important in determining the vulnerability of a coastline. During energetic wave climates (storm events) sediment rapidly erodes from beaches and is deposited offshore. In subsequent milder wave conditions, the sediment migrates shoreward, accreting on the beach and helping to protect the coastline. It...
The characterization of bathymetry and its time evolution is very important for both oceanographic science applications, and for societal reasons relating to coastal engineering
and development. Historically, the process of depth surveying has been costly and labor-intensive.
This is especially true in nearshore regions, hence a method that is both...
Most tsunami studies have been conducted based on the incompressible fluid theory. However water compressibility must be considered for the process of tsunami generation by bottom displacements during submarine earthquakes. During the 2003 Tokachi-Oki earthquake, the ocean-bottom pressure variations were registered by the pressure gauges PG1 and PG2 located right...
In the northwestern Gulf of Mexico there is a need for reliable water level forecasts to facilitate safe commercial navigation, marine construction, and emergency management. Though the low amplitude tides of the region can be predicted with conventional harmonic techniques, frequent strong storms make accurate forecasts of water levels difficult....
Knowledge of wave conditions in nearshore regions supports the development of
ocean wave energy technology by providing wave climatology for device design
considerations, and power output estimates. By modeling wave transformation
over the continental shelf, wave conditions were predicted in nearshore regions
where potential wave energy conversion sites are located....
This thesis is comprised of a manuscript based on a laboratory experiment run in the Tsunami Wave Basin as part of a research project funded by the Network for Earthquake Engineering Simulation called Housesmash. The purpose of the experiment was to better understand the role of the urban environment, represented...
This thesis presents the details of a large-scale laboratory experiment to study the
turbulence generated by waves breaking on a fixed barred beach. The data set includes
comprehensive measurements of free surface displacement and fluid velocity for one
random and one regular wave case.
Observations of the time-averaged turbulent kinetic...
Coastal foredunes protect lives, infrastructure, and ecosystems during severe winter storms. In the U.S. Pacific Northwest (PNW), coastal foredune geomorphology is determined by both physical and ecological mechanisms. Before the 1900's, the native plant Elymus mollis was the dominant dune grass and dune morphology was largely determined by sediment supply...
The use of data extracted from particle image velocimetry (PIV) along with vector and tensor visualization techniques provides a valuable tool for understanding a complex flow field. By studying a simple geometric structure such as a cylinder under a simple transient waveform, fundamental mechanisms of wake development under solitary wave...
This thesis is comprised of two manuscripts based on a laboratory experiment conducted to examine realistic wave forcing on a vertical wall subjected to tsunami loading. The first manuscript examined tsunami force and pressure distributions on a rigid wall that was fronted by a small seawall. Six different seawall heights...
The acoustic signals produced by the Dungeness crab (Cancer
magister) were investigated. The signals were examined for duration times and frequency content. The signals were converted from analog to digital form, and the autocorrelation functions and the power density spectrums were determined.
The signals produced by Dungeness and Japanese red...
An experiment on solitary wave impact on a vertical cylinder was conducted in the three-dimensional wave basin at the Oregon State University Hinsdale Wave Research Laboratory. The cylinder was designed using mechanic principles and finite element analysis techniques to enable accurate measurement of horizontal force and overturning moment. Video data...
The experimental setup and data are presented for a laboratory experiment conducted to examine realistic wave forcing on a highway bridge superstructure. The experiments measure wave conditions along with the resulting forces, pressures, and structural response of a 1:5 scale, reinforced concrete model of a typical section of the I-10...
An interesting means of shoal removal has recently been implemented by the U.S. Army Corps of Engineers for use in shallow Pacific
Coast tidal inlets and estuaries. In the past, removal of shoaled material has consisted of physical excavation of material, transportation from the site, and placement in a spoils...
With energy prices rising and increasing concern about the influence of fossil fuels on climate change, wave energy systems are on the verge of commercial implementation. These first generation wave energy converters utilize either pneumatics or hydraulics to convert the mechanical energy of waves into electricity. For the last several...
The mouth of the Columbia River (MCR) has a longstanding reputation of hazardous navigational conditions. This reputation has been developing since the first ship, the Columbia, traversed through the inlet in 1792. The hazardous conditions are related to the large waves and strong tidal currents that are common in the...
Understanding the past, present, and future behavior of our nation's shorelines is vital for sensible coastal management. Localized areas of erosion, termed "erosional hot spots", can shift the shoreline landward threatening coastal infrastructure (Kraus and Galgano, 2001; Stauble and Gravens, 2004; McNinch, 2004). One specific type of erosional hot spot...