A5076818835- Wave and Wind Energy Systems
- Coastal and Marine Dynamics
- Ocean Waves and Remote Sensing
- Fluid Dynamics and Vibration Analysis
- Oceanographic and Atmospheric Processes
- Tropical and Extratropical Cyclones Research
- Underwater Acoustics Research
- Methane Hydrates and Related Phenomena
- Arctic and Antarctic ice dynamics
- Earthquake and Tsunami Effects
- Fluid Dynamics Simulations and Interactions
- Boron and Carbon Nanomaterials Research
- Magnesium Oxide Properties and Applications
- Metal and Thin Film Mechanics
- Offshore Engineering and Technologies
- Magnesium Alloys: Properties and Applications
- Advanced ceramic materials synthesis
- Aluminum Alloys Composites Properties
- Marine and environmental studies
University of Washington Applied Physics Laboratory
2023-2025
University of Washington
2023-2024
University of Massachusetts Amherst
2020-2023
Abstract The sea surface and air-sea exchange processes have been identified as essential for both short- long-term atmospheric ocean forecasts. two phases of the fluid layer covering our planet interact across a vast range scales that we need to explore achieve better understanding processes. While satellites provide distributed large-scale view situation, highly detailed measurements, e.g., from oceanographic towers, are necessarily local. An intermediate solution can be provided by swarms...
Expendable microSWIFT buoys have been developed and tested for measuring ocean surface waves. Wave spectra are calculated via onboard processing of GPS velocities sampled at 5 Hz, wave delivered to a shore-side server Iridium modem once per hour. The microSWIFTs support additional sensor payloads, in particular seawater conductivity temperature. non-traditional, cylindrical shape that is required deployment the dropsonde tube research aircraft. Multiple versions tested, with design...
Abstract Drifting buoy observations of ocean surface waves in hurricanes are combined with modeled wind speeds. The include targeted aerial deployments into Hurricane Ian (2022) and opportunistic measurements from the Sofar Ocean Spotter global network Fiona (2022). Analysis focuses on slope waves, as quantified by spectral mean square slope. At low‐to‐moderate speeds (<15 m s −1 ), slopes increase linearly speed. higher winds (>15 continue to increase, but at a reduced rate. extreme...
Abstract Drifting buoy observations in Hurricane Idalia (2023) are used to investigate the dependence of ocean surface wave mean square slope on wind, wave, and storm characteristics. Mean has a primary wind speed that is linear at low‐to‐moderate speeds approaches saturation high (20 m ). Inside Idalia, buoy‐measured slopes have secondary wind‐wave alignment: given speed, higher where waves aligned compared crossing. At moderate speeds, differences between crossing conditions can vary...
Magnesium is widely regarded as an excellent structural material, primarily because it forms the basis for a range of light-weight high-strength alloys. Recently, high-strain rate deformation magnesium has received great deal attention due to complicated modes that involve combinations dislocation slip and twinning. In this study, single crystal samples were shock-compressed along c- a-axis, then released back ambient conditions. Post-mortem transmission electron microscopy revealed...
Abstract The attenuation of ocean surface waves during seasonal ice cover is an important control on the evolution Arctic coastlines. spatial and temporal variations in this process have been challenging to resolve with conventional sampling using sparse arrays moorings or buoys. We demonstrate a novel method for persistent observation wave‐ice interactions distributed acoustic sensing (DAS) along existing seafloor fiber optic telecommunications cables. DAS measurements span 36‐km...
In this paper, we will discuss the ongoing progress by Sofar in contributing to state-of-the-art hurricane prediction efforts as part of National Oceanographic Partnership Program (NOPP) Hurricane Coastal Impacts (NHCI) project, a joint collaboration between government, academic and industry partners. Through massive collaborative effort across remote sensing, situ observations, numerical modeling, project is working improve our capacity predict impacts coastlines - from coastal erosion...
The processes important to hurricane wave generation cover scales from kilometers centimeters. Within a storm, waves have complex spatial variations that are sensitive size, strength and speed. This makes it challenging measure the variability of with any single instrument. To obtain both broad coverage resolve full range scales, we combine arrays drifting buoys airborne radar altimetry. microSWIFT (UW-APL) Spotter (Sofar) air-deployed along given storm track. These scalar frequency spectrum...
Air-sea exchange processes have been identified as essential for both short- and long-term atmospheric ocean forecasts. The two phases of the fluid layer covering our planet interact across a vast range scales that we need to explore achieve better understanding processes. While satellites provide distributed large-scale view sea surface situation, highly detailed measurements, e.g., from oceanographic towers, are necessarily local. required intermediate solution (i.e., data accurate...
Abstract This paper analyzes the power capture potential, structural loadings, and costs associated with an oscillating surge wave energy converter (OSWEC) operating on a raised foundation. The OSWEC offers opportunities for reduced installation costs, improved production, greater flexibility of deployment when compared fixed-bottom models. In this investigation, we simulated several different foundation geometries using WEC-Sim to estimate loads. effort maximize capture, cases in which flat...
The attenuation of ocean surface waves during seasonal ice cover is an important control on the evolution many Arctic coastlines. spatial and temporal variations in this process have been challenging to resolve with conventional sampling using sparse arrays moorings or buoys. We demonstrate a novel method for persistent observation wave-ice interactions distributed acoustic sensing (DAS) along existing seafloor telecommunications cables. DAS measurements span 36-km cross-shore cable Beaufort...
Abstract Oceans are harsh environments and can impose significant loads on deployed structures. The deployment of wave energy converters (WECs) faces a design challenge with apparently contradictory goals. A WEC should be designed to maximize the absorbed while ensuring operating condition does not exceed failure limits device itself. Therefore, endured by support structure constraint for system. Adaptability different sea states is, therefore, highly desirable. This work uses WEC-Sim model...
In order to improve their long-term viability, wave energy converters (WEC) need be able shed loads when a threshold condition is exceeded. As shown by Tom et al. [1], provision of adjustable flaps within the body an Oscillating Surge Wave Energy Converter (OSWEC) allows pass through device. A control system may then open and close waves approaching device exceed preset thresholds. The variable geometry OSWEC concept studied in this paper bottom-hinged rectangular paddle with five elliptical...
Abstract Oceans are harsh environments and can impose significant loads on deployed structures. A wave energy converter (WEC) should be designed to maximize the absorbed while ensuring operating condition does not exceed failure limits of device itself. Therefore, endured by support structure a design constraint for system. Furthermore, WEC adaptable different sea states. This work uses WEC-Sim model variable-geometry oscillating (VGOSWEC) mounted simulated under scenarios. VGOSWEC resembles...
Abstract Experiments were conducted on a wave tank model of bottom raised oscillating surge energy converter (OSWEC) in regular waves. The OSWEC shape was thin rectangular flap, which allowed to pitch response incident waves about hinge located at the intersection flap and top supporting foundation. Torsion springs added order position natural frequency center range maker. motion as well loads base foundation measured. modeled analytically using elliptic functions obtain closed form...
Abstract In real ocean environments, offshore structures are exposed to a combination of wave and current loading conditions. This scenario presents the need study fluid-structure interactions in presence both conditions, achievable through experimentation recirculating flume coupled with wavemaker. The Ocean Resources Renewable Energy (ORRE) group set out design wave-current at University Massachusetts Amherst enable technologies such as scale floating platforms marine energy converters....
To develop transparent materials with superior mechanical properties, nanocrystalline magnesium aluminate (MgAl2O4) spinel grain sizes ranging from 3.7 to 80 nm has been synthesized by environmentally controlled pressure assisted sintering (EC-PAS). In this study, we investigated the microstructure and size dependence of properties MgAl2O4 performing transmission electron microscopy, nanoindentation, uniaxial micropillar compression, micro-cantilever bending. Electron microscopy confirmed...