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The Hayes Coastal Engineering Laboratory is a new laboratory with two water basins: a 45.72-meters long, 3.66 meters wide and 3.06 meters deep Tow Tank with sediment pit for dredging and current flow studies, and a 36.58 meters long, 22.86 meters wide and 1.22 meters deep 3D Wave Basin for coastal wave studies. In order to assess the capabilities of the lab a series of tests were done in both tanks. Hydrodynamic tests in the Tow Tank using a Micro Acoustic Doppler Velociometer measured current flow in the tank and assessed the efficacy of different filters to stabilize flow patterns. A concrete dam structure installed near the reversed diffusers most effectively stabilized flow of all the configurations tested. Wave tests were conducted in the 3D Wave Basin with the newly-installed 48 paddle Rexroth wave generator at 0.5 and 1.0 meter water depths using wired and wireless capacitance wave gauges. These tests measured characteristics of the generated waves and reflection from the rubble-mound beach. In addition, initial testing of the Active Reflection Absorber (ARA) system was done. Correlating the wave data to the theoretical wave being produced showed that with water depth of 0.5 meters the 0.1 meter waves were well-formed, but the 0.2 meter waves showed energy loss and lower correlation. The results from one meter water depth wave tests showed good formation of 0.2 meter waves. In nearly all wave tests with pool buoys installed the waves were better formed with good correlation and a better fitting power spectrum. The beach reflection was within the expected value range, being ten percent and below for most tests. ARA, while operational, needs to be further tuned to find the settings that will increase its effectiveness.

The thesis provides the required knowledge base for establishing Laser Induced Stress Wave Thermometry (LISWT) as a viable alternative to current infrared technologies for temperature measurement up to 1000°C with ±1°C resolution. The need for a non-contact, high resolution thermal measurement methodology applicable to Rapid Thermal Processing (RTP) motivated the work. A stress wave propagation model was developed and a complex, temperature-dependent elasto-viscoplastic constitutive law was identified. A stagger-grid finite difference scheme was followed to approximate the solution field subject to temperature and plate thickness variations. Extensive numerical experiments were conducted to identify the proper time and spatial steps. A Gabor wavelet transform scheme was also employed for the extraction of wafer thermal and geometric information from exploring wave attenuation and dispersion. Researched results concluded that wave group velocity is a nonlinear function of temperature. Nonlinearity became more prominent at high temperatures and low frequencies. As such, for LISWT to achieve better thermal resolution at high temperatures, low frequency components of the induced stress wave should be exploited. The results also showed that the influence of temperature on attenuation is relatively small. It is not recommended to use attenuation for resolving temperature variation as small as several degrees Celsius. In addition to temperature, geometry also was found to have an impact on wave dispersion and attenuation. The results showed that the influence of thickness on wave velocity is significant, thus suggesting that for LISWT to achieve high temperature resolution, wafer thickness must be accurately calibrated in order to eliminate all possible errors introduced by thickness variation. The study established the basic framework for LISWT to be applicable to silicon wafer RTP at elevated temperatures. The model and methods developed for the course of the research can be easily adapted to account for other nondestructive evaluation applications involving the use of surface, plate or bulk waves for material characterization and thermal profiling.

The damaging effects of hurricane landfall on US coastal bridges have been studied using physical model testing. Hurricane bridge damage and failure susceptibility has become very evident, especially during hurricane seasons 2004 and 2005 in the Gulf of Mexico. The combination of storm surge and high waves caused by a hurricane can produce substantial loads on bridge decks leading to complete bridge failure. Several theoretical methods have been developed to estimate these forces but have not been tested in a laboratory setting for a typical bridge section. Experiments were done using a large-scale 3-D wave basin located at the Haynes Coastal Engineering Laboratory at Texas A&M University to provide estimates of the horizontal and vertical forces for several conditions to compare with the forces predicted with the existing models. The wave force results show no strong correlation between the actual force measured and the predicted force of existing theoretical methods. A new method is derived from the existing theoretical methods. This model shows a strong correlation with both the measured horizontal and vertical forces.

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Three kinds of propagating waves physically admissible in a tubular section are derived to establish their dispersion characteristics in response to the presence of multi-layered viscoelastic coatings. One is the longitudinal wave that propagates in the axial direction. The other two are shear and longitudinal waves along the circumferential direction. To characterize the hollow cylinder with coating layers, wave dispersion and attenuation are studied using the “global matrix” technique. Since each layer is considered to be perfectly bonded to each other, displacement and strain continuity are imposed as the interfacial boundary conditions. Viscoelastic coating materials such as bitumen and epoxy serve to improve pipeline reliability, but they also dampen and dissipate wave energy. The viscoelastic materials are studied as well. By replacing the real material constants with complex material constants in the characteristic equation, the impact of the viscoelastic coatings on wave dispersion is established. Bisection method is followed to find the real and complex roots of the three characteristic equations derived. Roots thus obtained are manipulated to allow the phase velocity and attenuation dispersion to be plotted against frequency. The dispersion of phase velocity and wave attenuation for coated pipes are evaluated against a baseline model which is the bare, uncoated tubing to establish the propagation characteristics of the guided shear and longitudinal waves in the presence of multiple coating layers. The effects of increasing attenuation parameter and coating thickness are also investigated.

At the Division for Electricity at Uppsala University a new marine substation for waveenergy is being built. The marine substation is required to connect the wave energyconverters to the grid. In this thesis a part of the main circuit for the marinesubstation is assembled and tested. Furthermore, a part of the measurement system isdesigned and a prototype is built and evaluated. The test results from the set-up ofthe main circuit agree well with simulations done in MATLAB Simulink. A detailed listof components combined with a finished CAM-model for a measurement card arepresented along with interface cards and shielding solutions.

Wave energy converters (WECs) are relatively new power sources under rapiddevelopment. WECs utilize permanent magnets to generate power and theperformance of these magnets have a great impact on the produced effects in theWECs. This paper is primarily constructed to investigate the magnetic and mechanicalproperties of a specific kind of permanent magnets, referred to as Y40. The paperalso gives a comprehensive review of magnetic materials in general, slightly focusingon magnetic stability. Literature studies has been made to get an understanding ofhow the Y40 magnets will perform under external influences such as reversed field,temperature change and mechanical stress. Further, a compression test has beenmade to examine the Y40s solidity. From the results of the tests and from theinformation provided in literature it is considered to be little to no risk for the Y40sto lose magnetization due to external influences. However, because of theirassembled structure, the Y40 magnets are very likely to break in their joints duringpressure lower than what is expected in the WECs.

In this thesis,I discuss the wave pass on submerged bweakwater,and theheight of submerged breakwater,different slope of submerged breakwater with breaking wave relations.I do experiment to find the regular between breaking wave and the design of submerged breakwater.I use different submerged breakwater,there are two slope.There are 1/2 and 1/5.The height of submerged breakwater is 45 cm,the wide of submerged breakwater is 75 cm.the water deep is from 50cm to 90 cm,Wave cyclical is from 1.2 sec to 2.7 sec,I use H L to choose wave height,and save the data of incident wave.and then I analysis the data to get t K and energy.I also memorize the site of breaking wave and breaking type. From the experiment ,we know that wave do not be broken, be broken, and the regular of breaking wave and breaking type ,so we can use the regular to design the height of submerged breakwater, the slope of submerged breakwater. So we can use the least costs to protect the seacoast. When we know local wave condition, we can design the height of submerged breakwater to break wave that is dangerous for seacoast ,or we want to break wave when the wave height at 1 m or 2 m or others design the height of submerged breakwater. When £m^2h/g is between 0.3 and 2.5,we can find that when R/H0¡¦ is smaller than 1,the wave will break¡CWhen wave break bysubmerged breakwater ,we can find the slope of 1/5 is better than the slope of 1/2 to reduce the wave.Both slope of 1/2 and slope of 1/5 are effective to reduce wave energy at Hi/R=2.

This study investigated Floating Production Storage and Offloading (FPSO) responses under wave and current interactions. A higher order boundary element method (HOBEM) was adopted to probe the behavior of an FPSO. Forces and moment of an FPSO were studied under wave and current interactions. The simulations of diffracted and radiated waves were performed in a time domain. Time marching schemes were used for this time domain calculation. The predictor-corrector(P-C) method was used. Boundary integral equations were used to solve each problem with Rankine sources and distributed over the entire calculation domain. For the far-field boundary condition, Orlanski’s truncated open boundary condition was used for an open truncated boundary condition to prevent reflected waves. The current effect was considered an explicit term due to being a moving coordinate. Various current heading angles were also studied. Truncated open boundary, maximum likelihood method, proper element size and shape, modulation function, and Chebyshev filtering were studied to avoid diverged solutions. From our findings, higher order elements fitted a complicated model such as an FPSO. We found that this method required considerably fewer elements than the constant panel method in order to obtain reasonable outcomes. Using our developed numerical method, we calculated wave forces and moment, mean drift forces, added mass, and damping coefficients. Conclusively, HOBEM was found to be more effective and more reliable in calculating and predicting wave and current influence on an FPSO. Future studies are needed to develop finer simulation tools for FPSO’s large horizontal behavior.