Grandelli P.,Makai Ocean Engineering, Inc.
Journal - American Water Works Association | Year: 2011
The Lake Oswego Interceptor Sewer (LOIS) project that was completed included the replacement of a 50-year-old corroded, undersized, and seismically vulnerable concrete cylinder sewer pipe under the lake with a larger, flexible, high-density polyethylene (HDPE) pipeline. The design team identified and evaluated a variety of alternatives to address these deficiencies, including rehabilitation of the existing pipeline and its supports and replacement using a buoyant system to hold the pipe at the correct underwater elevation. The challenges with the project included nearly horizontal slope required tight placement tolerances of all pipe supports to prevent low spots in the finished pipeline profile and a wide range of lake temperature from 42 to 7 °F at pipeline depth required special measures to accommodate significant thermal expansion and contraction of the pipeline. To address this design challenge, S-shape concept allowed the pipeline to expand and contract without lateral and corresponding vertical displacement. Source
Anderson J.C.,Makai Ocean Engineering, Inc. |
Garth C.,University of California at Davis |
Duchaineau M.A.,Lawrence Livermore National Laboratory |
Joy K.I.,University of California at Davis
IEEE Transactions on Visualization and Computer Graphics | Year: 2010
A new material interface reconstruction method for volume fraction data is presented. Our method is comprised of two components: first, we generate initial interface topology; then, using a combination of smoothing and volumetric forces within an active interface model, we iteratively transform the initial material interfaces into high-quality surfaces that accurately approximate the problem's volume fractions. Unlike all previous work, our new method produces material interfaces that are smooth, continuous across cell boundaries, and segment cells into regions with proper volume. These properties are critical during visualization and analysis. Generating high-quality mesh representations of material interfaces is required for accurate calculations of interface statistics, and dramatically increases the utility of material boundary visualizations. © 2006 IEEE. Source
Agency: Department of Defense | Branch: Navy | Program: STTR | Phase: Phase I | Award Amount: 150.00K | Year: 2011
In coordination with the SPAWAR Systems Center, San Diego, Makai Ocean Engineering, Inc. proposes to develop an autonomous Array Burial Vehicle (ABV) to install U.S. surveillance arrays. The proposed work focuses on: (a) developing an overall vehicle concept for an autonomous vehicle that will install and bury an underwater sensor array to protect it against fishing threats, (b) performing analytical and experimental analysis of critical elements of the installation and burial system to characterize the physical limits and trade-offs of the system proposed, and (c) providing convincing support of the feasibility of the proposed conceptual design, integration techniques, installation method and approximate cost. Makai"s innovative use of water jetting technology in the ABV substantially decreases the power requirements when compared to conventional plowing techniques. The jetting components, which are small in size and consume low amounts of power, will be incorporated into a light weight"torpedo shape"vehicle. The light weight ABV will help minimize the propulsion requirements, further decreasing component sizes and overall cost. The ABV will be more manageable and easily deployed from a variety of platforms, allowing the Navy to deploy arrays in softer soils and steeper slopes than those that can be achieved with conventional plows.
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 99.79K | Year: 2009
Ocean Thermal Energy Conversion (OTEC) has the potential of supplying large quantities of renewable electrical power to U.S. island communities in tropical waters. Large OTEC plants can be economical if they are (1) offshore floating plants that can be mass produced and (2) capable of providing at least 100MW in capacity. Today, no electrical transmission cables can deliver this power to shore under the extreme depths, high voltage, and dynamic conditions of a floating, dynamically moving OTEC Structure. The cable must endure high tensions due to its depth, continued motions due to the movement of the OTEC plant, and motions relative to the seabed at touchdown. Although commercial submarine power cables exist for high power in shallow water, and for low power for dynamic applications, none provide the combination of high power and high voltage in deep and dynamically moving water. This project will develop such a cable, enabling OTEC power plants to be a viable source of alternative energy. In Phase I, the design of a submarine power cable will be initiated by combining designs for electrical transmission from the OTEC plant to the shore, for the overall global configuration of the cable, and for cable installation. Commercial Applications and other Benefits as described by the awardee:A submarine high-voltage power cable system for dynamic, deep ocean conditions would enable Ocean Thermal Energy Conversion (OTEC) to supply renewable electrical energy to tropical areas (Hawaii, Guam, Puerto Rico, DOD bases).
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase I | Award Amount: 80.00K | Year: 2015
Makai proposes to complete a parametric analysis of candidate sonobuoy components for a conceptual deep drifting sonobuoy system. These results will enable the Navy to perform a tradeoff analysis of the sonobuoy system to meet their operational requirements and form-factor constraint. Using Navy-supplied location data, Makai will characterize the ocean environment in the area of operation and use Navy 4D temporal ocean current models as input to a hydro-mechanical numerical model to evaluate the dynamic loads on the different sonobuoy components (especially on the long and thin tether) will be compared to the manufacturer-specified component limits. The drift of single and multi-buoys over 30 days will be observed, as the acoustic coverage is an important metric for the Navy. The goal of this parametric study is to characterize how various component parameters (e.g., tether diameter, sizes, drag, weights, specific gravities): 1) affect individual sonobuoy space and weight; 2) perform against the system 30-day operational requirement and form-factor constraint; and, 3) influence single and multi-buoy geometry and barrier drift.