Mid-September
2006
Table
of Contents:
Chesapeake Section |
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Texas Section |
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Mid-September
2006
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Chesapeake
Section April 18, 2006 ASNE and SNAME Sections Host Student Projects On Wednesday April 18, 2006, SNAME Chesapeake Section and the Flagships section welcomed 14 students from the U.S. Naval Academy and Virginia Tech. Three different design projects were presented to a very attentive audience, which included the Deputy Commander of NAVSEA, RDML Chuck Goddard. Virginia Tech Teams 3 and 1 During
the 2005-2006 school year at Virginia Tech, four teams were brought together
to work on two different “designs” either a guided missile
submarine or a cruiser. In previous years we have had short presentations
from each team, but this year they decided to present the best of each
of the teams.
The design developed by VT Team 3 covered the concept exploration and design development of an air independent submarine armed with cruise missiles capable of undertaking covert intelligence, surveillance, and reconnaissance missions. During the concept exploration phase of their study the students investigated a wide range of air independent propulsion concepts for their design. Through the use of pareto-genetic modeling they were able to perform an overall trade-off of many of the concepts and identify several potential specific design points for further study. The final specific design point that was selected for the design included a conventional teardrop shaped hull with parallel mid-body and a length to diameter ratio of about 7. The design was powered by Polymer Electrolyte Membrane (PEM) type fuel cells, which were chosen due to there relatively advance state of maturity as air independent propulsion systems. These fuel cells generate power-using hydrogen, in the form of Hydride (H2) Overall the design was developed to be capable of deploying underwater at 5 kts for 26 days as well as being able to snorkel at speeds up to 12 kts. One particular item noted by he students was the fact that almost one-third of the hull was allocated for ballast. This was due in part to the high range requirement of the vessel, which resulted in a large capacity requirement for the H2 tanks, and the need to compensate for this fuel as it is consumed. VT Team 1 presented their design study of a “CG(X) - Air Superiority Cruiser”. The This team consisted of James Schultz, Justin Baity, Rich Hardy, Erika Kast, Nate Reimold, and John Wilde. The design developed by VT Team 1 covered the early concept exploration studies -as well as the design development of the specific design point chosen for further analysis. During the concept exploration phase pareto-genetic modeling was also used to investigate a wide range of concepts for their design.
The students noted that in general the vessel being designed was intended to be both a compliment to and eventually, the replacement for both the current CG 47 class cruisers and the DDG 51 class air warfare destroyers. The final design developed by the students consisted of a vessel with a tumblehome type hull and a wave-piercing bow. The design was outfitted with two 57mm guns, a wide aperture sonar, an advanced radar system, and a large number of Vertical Launch System missiles. Additionally, the design was configured with an integrated electrical propulsion system.
Midshipman Kenan Knieriem Jr, presented his individual project “Empirical Predictions of Foil Assisted Planing Catamarans”. Midshipman Knieriem noted that foil assisted planning catamarans are high-speed vessels where foils, attached between the main hulls and near the transom, provide lift equivalent to up to 60% of the vessel’s at some speeds. As part of his analysis, Midshipman Knieriem developed a mathematical computer model for estimating the performance of these type vessels, and then tested a representative in the Naval Academy’s 380-foot tow-basin to correlate and validate his predictions. The model was designed to allow for testing over a range of incidence angles for the foils, and could also be tested without the foils, as a conventional high-speed catamaran for comparative purposes.
Overall
the author noted that the final math model developed in EXCEL performed
well and showed reasonable correlation with the model that was tested
in the tow tank, though at lower speeds there appeared to be some under
prediction of the resistance of the side hulls using the Savitsky method.
Texas
Section August 2006 Marco Polo TLP Full-Scale Monitoring - August Lunch Meeting The Texas Section had a record turnout in August for its last meeting of the 2005-2006 year. Over 90 people had signed up to hear Dr. Johan Wichers from Marin USA discuss the data recorded as part of a Full-Scale Monitoring Joint Industry Project (JIP). In May of 2004, the monitoring equipment was installed on the Marco Polo Tension Leg Platform (TLP, located in the Gulf of Mexico, just in time for the hurricane season. Sure enough, a few months after the installation, Hurricane Ivan passed within 120 miles of the platform, and severe waves and wind were recorded. The following season, Hurricane Katrina (within 45 miles) and Hurricane Rita (within 28 miles) came through the Gulf of Mexico and provided more information for the JIP. With permission of the JIP participants (and under the condition of no hand-outs) Dr. Wichers presented the data collected to date, and highlighted the varying relationships observed between wind and waves, and also on wave spreading. Although much good information has been collected during the past hurricane seasons, Dr. Wichers suggested that more hurricanes will be needed to gain a better understanding of the physics behind this weather phenomena. He ended his presentation with a promise of sharing with SNAME the results of the Vortex Induced Motions (VIM) and Vortex Induced Vibrations (VIV) that has been recorded under the condition that the participants of the JIP will give permission again.
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