As the ocean wave energy field continues to mature,
developers need a generic modeling methodology to test their
designs before building prototypes. A design methodology for a
first-pass time-domain simulation is a goal of this work. Built on
results from the frequency domain analysis, the general
procedure for obtaining time...
Ocean wave energy converter technology continues to advance and new developers continue to emerge, leading to the need for a general design, modeling, and testing methodology. This work presents a development of the process of taking a wave energy converter from a concept to the prototype stage. A two body...
A six degree of freedom (6DOF) point-absorber wave energy converter (WEC) called LUPA is being developed at Oregon State University. This research focused on analyzing a full- scale LUPA, called LUPA20, to answer the following questions: 1) How does a full-scale WEC perform due to various factors; 2) What are...
As the sources of our electricity shift from centralized and carbon emitting, to a portfolio of distributed, clean-energy sources, the wave energy converter (WEC) has become a topic of exploration and development for providing coastal communities electric power. Part of this trend has included an effort to create open source...
Wave energy converters (WECs) show promising potential to significantly contribute to global renewable energy goals. Numerous WEC designs have been proposed and investigated, but wave energy conversion technology has yet to reach convergence in the same way wind or solar has. Of the designs currently in existence, surface-piercing WECs are...
A key component in bringing ocean wave energy converters from concept to commercialization is the building and testing of scaled prototypes to provide model validation. A one quarter scale prototype of an autonomous two body heaving point absorber was modeled, built, and tested for this work. Wave tank testing results...
A wide variety of hydrodynamic theories are utilized to approximate a Wave Energy Converter’s (WEC) equation of motion. Numerous theories have been refined in order to improve numerical approximations of WEC dynamics. When incorporating refined hydrodynamic theories into numerical models, there are distinct impacts on WEC rigid body motions, cable...
This work addresses the application of Nonlinear Model Predictive Control (NMPC) to a class of ocean wave energy conversion systems in which the cost functional is not in a standard quadratic form, and the WEC model includes the nonlinear effects, such as the hydrodynamic viscous drag. The NMPC implementation is...
Wave energy converter research continues to advance and new developers are continuing to emerge, leading to the need for a general modeling methodology. This work attempts to outline the design methodology necessary to perform frequency domain analysis on a generic wave energy converter. A two-body point absorber representing a generic...
Wave energy conversion is still in its infancy, and in order for it to become a commercially viable technology, developers, investors and utilities need to estimate a Wave Energy Converter's (WEC's) performance for the wave climate of a potential installation site. With the goal of estimating a design's power output...
Ocean waves provide a promising source of renewable energy for the North American electric grid. However, ideal control of wave energy converters (WECs) requires perfect forecasting of future wave conditions, and waves can be unpredictable. This paper presents a comparison of three different prediction methods and analyzes their performance in...
The potential for electric energy generation from ocean waves is substantial and much research is being conducted on the conversion process as a renewable, grid-connected, power source. Some of the same attributes that make wave energy harvesting attractive as a grid-connected source also make it attractive as a remote, or...
The performance of the power take-off (PTO) system for a wave energy converter (WEC) depends largely on its control algorithm. This paper presents an adaptive damping control algorithm that improves power capture across a range of sea states. Validation for the numerical model was performed using data from two sources;...
When the term renewable energy is mentioned in a conversation, wind, solar, and hydro energy typically come to mind. However, there is one major resource that has remained mostly untapped: wave energy. Wind and solar power technologies are well established around the world but they cannot generate electricity all the...
In 2008, the US Department of Energy’s (DOE) Wind and Water Power Program issued a funding opportunity announcement to establish university-‐led National Marine Renewable Energy Centers. Oregon State University and the University of Washington combined their capabilities in wave and tidal energy to establish the Northwest National Marine Renewable Energy...
Wave energy converters (WECs) are a broad class of emerging technology that converts hydrokinetic energy into some other useful form, such as electricity. The last stage in this transformation, the power take-off (PTO) subsystem, is often not experimentally evaluated until half-way through the recommended development process. This delay in evaluation...
Continual growth of the world's energy consumption and the demand for long-term clean renewable energy resources has led to the development of ocean-based wave energy technologies. Emerging technologies are advancing potential solutions to the complex problem of energy generation in the harsh and corrosive ocean environment. To develop these technologies,...
The Large Wave Flume at the O.H. Hinsdale Wave Research Laboratory houses a piston wavemaker with a built-in active absorption system designed by MTS Systems Corporation. The performance of the active absorption system has not been properly assessed yet. This thesis evaluates the performance of the MTS active absorption system...
Multiple wave energy converter (WEC) archetypes exist with varying power take-off (PTO) designs in the attempt to maximize ocean energy harnessed and converted into useful energy. The pendulum PTO is popular for its simple, yet robust functionality due to its internally located components and simple operation. Additionally, this PTO does...
Ocean testing of Wave Energy Converter (WEC) prototypes is necessary to facilitate commercial WEC development. The Ocean Sentinel Instrumentation Buoy, completed in August 2012, provides a stand-alone load for WEC prototypes during ocean testing. The first part of this work was to develop the power conversion and data acquisition equipment...
In coastal and ocean engineering, understanding the ocean environment and the forces from waves, tsunamis and waterborne debris on structures and floating bodies is an important aspect of designing safe and effective infrastructure. Understanding the impact of these forces on structures becomes an important question in the design process. Answering...
Submerged aquatic vegetation (SAV) species, such as seagrasses, are highly valued in estuaries because of the many economic, ecological, and cultural services that they provide, including shelter for fisheries, minimizing water turbidity, and improving am-bient water quality. SAV can also alter its physical environment by attenuating wave and current velocities,...
Converting energy from ocean waves is a challenging area for control theory application because of the nonlinear dynamics in various time scales. Generally, wave energy converter (WEC) control is applied in order to maximize power absorption, in the most common wave conditions, and subject to the devices’ physical constraints. Commonly,...
There is a perceived trade-off between fire risk reduction and northern spotted owl habitat protection in dry-conifer forests in southwestern Oregon. Management options for balancing this trade-off need to be sought at the landscape level. Applied landscape ecology suggests three important features to consider are (1) patch size and configuration...
Wave energy converter (WEC) devices are complicated systems containing hydrodynamic, mechanical, and electrical elements. WEC design efforts are primarily focused in the time-domain, using frequency-based energy analyses and numerical problem solving approaches that are staples in hydrodynamic design efforts to form the basic information set used in these time-domain development...
Physical modelling is instrumental to the progression of coastal engineering research and our understanding of the offshore and nearshore environments. Scaled models are designed and built to be tested in coastal research laboratories, where a wave basin or flume generates the desired wave conditions for experimentation. The surrounding hydrodynamics of...
Wave energy is one of the most promising renewable energy sources. Thus, research in this field has increased substantially over the last decade. However, significant costs associated with development and maintenance have so far impeded the implementation of commercially viable projects. Furthermore, the hydrodynamic interactions between water and prototypes meant...