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Full-Text Articles in Engineering

Pressure Effect On An Ocean-Based Humidification-Dehumidification Desalination Process, Yingchen Yang Oct 2019

Pressure Effect On An Ocean-Based Humidification-Dehumidification Desalination Process, Yingchen Yang

Mechanical Engineering Faculty Publications and Presentations

A new humidification-dehumidification (HDH) desalination process is proposed and analyzed. Being ocean based, the process does not produce any brine. It is largely powered jointly by solar energy, wind energy, and various types of ocean energies in a nearly natural way. A vacuum pump is employed to drive the air circulation throughout the HDH process. It is the only unit that consumes electricity. The HDH process is analyzed under various conditions, including using a low pressure (as low as to 0.2 atm) for humidification and the ambient pressure for dehumidification, running the entire HDH process around a low pressure (as …


Dynamic Response Modeling Of High-Speed Planing Craft With Enforced Acceleration, Gene Hou, Brain Johnson, Jonathan Degroff, Steven Trenor, Jennifer Michaeli Oct 2019

Dynamic Response Modeling Of High-Speed Planing Craft With Enforced Acceleration, Gene Hou, Brain Johnson, Jonathan Degroff, Steven Trenor, Jennifer Michaeli

Mechanical & Aerospace Engineering Faculty Publications

An approach is investigated in this study for structural dynamic analysis of a high-speed planing hull, in which the pointwise acceleration data collected from sea trials are enforced as base excitation. The paper first performed the full boat analysis of an 11-meter high speed craft for a period of one wave impact selected from each of nine seakeeping runs. The sea trial acceleration data collected from 11 accelerometers placed close to the centerline and the keel are enforced as input, while those from 3 accelerometers placed around the pilot cabin are selected for validation. The substructure dynamic analysis of the …


Sensor Development To Utilize Underwater Electric Potential (Uep) Fields To Navigate The Underwater Areas Of Ship Hulls, Caglar Erdogan Sep 2019

Sensor Development To Utilize Underwater Electric Potential (Uep) Fields To Navigate The Underwater Areas Of Ship Hulls, Caglar Erdogan

Link Foundation Ocean Engineering and Instrumentation Fellowship Reports

Underwater electric potential fields occur due to natural reasons, such as changes in atmosphere, ionosphere, magnetosphere, and movements of water bodies in the ocean, or artificial reasons, such as stray and controlled electric currents, or both. Electric potential fields around ship hulls are mainly generated due to corrosion protection systems and dissimilar materials. The electric field intensity over an impressed current anode of a large cruise ship operating in with seawater with a resistance of 20 0-cm is around 90 mV/cm, whereas it is between 0.4 and 1 mV/cm on a propeller for the same ship. The theoretical field intensities …


Surface Kinetic Energy Distributions In The Global Oceans From A High-Resolution Numerical Model And Surface Drifter Observations, Xiaolong Yu, Aurelien Ponte, Shane Elipot, Dimitris Menemenlis, Edward Zaron, Ryan Abernathey Aug 2019

Surface Kinetic Energy Distributions In The Global Oceans From A High-Resolution Numerical Model And Surface Drifter Observations, Xiaolong Yu, Aurelien Ponte, Shane Elipot, Dimitris Menemenlis, Edward Zaron, Ryan Abernathey

Civil and Environmental Engineering Faculty Publications and Presentations

The surface kinetic energy of a 1/48◦ global ocean simulation and its distribution as a function of frequency and location are compared with the one estimated from 15,329 globally distributed surface drifter observations at hourly resolution. These distributions follow similar patterns with a dominant low-frequency component and well-defined tidal and near-inertial peaks globally. Quantitative differences are identified with deficits of low-frequency energy near the equator (factor 2) and at near-inertial frequencies (factor 3) and an excess of energy at semidiurnal frequencies (factor 4) for the model. Owing to its hourly resolution and its near-global spatial coverage, the array of surface …


Cavitation Number As A Function Of Disk Cavitator Radius: A Numerical Analysis Of Natural Supercavitation, Reid Prichard Apr 2019

Cavitation Number As A Function Of Disk Cavitator Radius: A Numerical Analysis Of Natural Supercavitation, Reid Prichard

Senior Honors Theses

Due to the greater viscosity and density of water compared to air, the maximum speed of underwater travel is severely limited compared to other methods of transportation. However, a technology called supercavitation – which uses a disk-shaped cavitator to envelop a vehicle in a bubble of steam – promises to greatly decrease skin friction drag. While a large cavitator enables the occurrence of supercavitation at low velocities, it adds substantial unnecessary drag at higher speeds. Based on CFD results, a relationship between cavitator diameter and cavitation number is developed, and it is substituted into an existing equation relating drag coefficient …


The Tides They Are A-Changin’: A Comprehensive Review Of Past And Future Nonastronomical Changes In Tides, Their Driving Mechanisms And Future Implications, Ivan D. Haigh, Mark D. Pickering, J.A. Mattias Green, Brian K. Arbic, Arne Arns, Soenke Dangendorf, David Hill, David A. Jay, Multiple Additional Authors Jan 2019

The Tides They Are A-Changin’: A Comprehensive Review Of Past And Future Nonastronomical Changes In Tides, Their Driving Mechanisms And Future Implications, Ivan D. Haigh, Mark D. Pickering, J.A. Mattias Green, Brian K. Arbic, Arne Arns, Soenke Dangendorf, David Hill, David A. Jay, Multiple Additional Authors

Civil and Environmental Engineering Faculty Publications and Presentations

Scientists and engineers have observed for some time that tidal amplitudes at many locations are shifting considerably due to non-astronomical factors. Here we review comprehensively these important changes in tidal properties, many of which remain poorly understood. Over long geological time-scales, tectonic processes drive variations in basin size, depth, and shape, and hence the resonant properties of ocean basins. On shorter geological time-scales, changes in oceanic tidal properties are dominated by variations in water depth. A growing number of studies have identified widespread, sometimes regionally-coherent, positive and negative trends in tidal constituents and levels during the 19th, 20th and early …


Surf Zone Tilt Current Meter, Troy Heitmann Jan 2019

Surf Zone Tilt Current Meter, Troy Heitmann

Link Foundation Ocean Engineering and Instrumentation Fellowship Reports

Coastal tides and free surface gravity waves locally interact with the nearshore bathymetry generating spatially diverse circulation cells. Collectively, the cells form a current velocity flow field where net transport of geological, chemical, or biological, particulates takes place. Within the surf zone, dynamic instabilities lead to chaotic evolution and mixing, where single point, observations fail to quantitatively char­acterize the system as a whole. Governed by advanced theories, numerical models provide the necessary sampling resolution to study surf zone processes over large do­mains, but the model must be validated with field observations to draw meaningful conclusions. The acoustic Doppler current profiler …


Link Foundation Fellowship Report, Eric Nieves Jan 2019

Link Foundation Fellowship Report, Eric Nieves

Link Foundation Ocean Engineering and Instrumentation Fellowship Reports

Magnetic anomaly detection (MAD) is a leading technique for the detection and localization of obscured magnetic targets via exploiting the field anomalies they create. This is especially true in marine environments when looking for unexploded ordnance (UXO), because the DC magnetic field is not highly influenced by numerous types of media (i.e. water) or weather conditions. MAD is also a passive technique, which allows it to go unnoticed by the target. Whereas current applications of MAD have been shown to be effective for localizing single targets at a time, the development of a method for multiple localization would the robustness …


Developing In Situ Dissolved Inorganic Carbon Dioxide Instrumentation, Beckett Colson Jan 2019

Developing In Situ Dissolved Inorganic Carbon Dioxide Instrumentation, Beckett Colson

Link Foundation Ocean Engineering and Instrumentation Fellowship Reports

The ocean carbon system plays a critical role in regulating carbon dioxide content in the atmosphere. With increased anthropogenic carbon input, it is even more important to understand the system through measurements, models, and predictions. Unfortunately, the spatiotemporal resolution of ocean carbon system measurements is limited by a lack of in situ instrumentation. The support of the Link Foundation Ocean Engineering and Instrumentation Fellowship has enabled me to make significant progress in developing an in situ carbon system instrument for the deep sea. The instrument will measure both total dissolved inorganic carbon (DIC) and the partial pressure of carbon dioxide …