Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 77-78). Also available via the Internet.

Thesis (Ph.D)--Mechanical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Rogers, P. H.; Committee Member: Ferri, A. A.; Committee Member: Ruzzene, M.; Committee Member: Smith, M. K.; Committee Member: Trivett, D.; Committee Member: Zinn, B. T. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis (M.S. in Meteorology and Physical Oceanography)--Naval Postgraduate School, March 2006. / Thesis Advisor(s): Peter C. Chu. Includes bibliographical references (p. 131-132). Also available online.

This thesis examines the shift of torpedo production responsibilities from military to civilian manufacturers as a case study in the use of civilian resources during World War II. The existing structure of the U.S. Navy Bureau of Ordnance failed to produce adequate torpedoes for the first two years of American wartime activity. The Bureau therefore abandoned the existing structure and shifted production to civilian contractors. This change occurred within the broader context of civilian scientific and technica1 invo1vement in military matters during World War II. The torpedo story illustrates one organization's unintentional participation in this process. / Master of Arts

International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The performance testing of underseas weapons involves many of the same challenges as for other “smart” systems. Data sets on the order of GigaBytes must be extracted, processed, analyzed, and stored. A few KiloBytes of significant information must be efficiently identified and accessed for analysis out of the great mass of data. Data from various sources must be time correlated and fused together to allow full analysis of the complex interactions which lead to a given test result. The fact that the various sources all use different formats and medias just adds to the fun. Testing of underseas weapons also involves some unique problems. Since real time data transmission is not practical; the vast bulk of the test data is recorded and then recovered with the vehicle at the end of the test. Acoustics are relied on for identification and ranging. As systems continue to get smarter; the rates, capacities, and “smarts” of the equipment and software used to process test data must similarly increase. The NUWES telemetry capabilities developed to test and analyze underseas weapons could be of use on other government related projects. “Key words: Telemetry, data processing, data analysis, undersea weapons, smart weapons, torpedoes, performance testing.”

The purpose of this thesis is to investigate the value-added of the Navy's nowcast/forecast and GFO satellite to the naval antisubmarine warfare (ASW) and anti-surface warfare. For the former, the nowcast/forecast versus observational fields were used by the WAPP to determine the suggested presets for MK 48 variant torpedo. The metric used to compare the two sets of outputs is the relative difference in acoustic coverage area generated by WAPP. Output presets are created for five different scenarios, two anti-surface warfare scenarios and three ASW scenarios, in each of two regions: the East China Sea and South China Sea. Analysis of the output reveals that POM outperforms MODAS in all tactic scenarios. For the latter, the MODAS (T, S) profiles were used by the WAPP to determine suggested presets for Mk 48 variant torpedo. The only difference in the MODAS fields was the altimeter used to initialize the respective MODAS fields. The same metrics used in the nowcast/forecast case were used to generate and compare the acoustic coverages. Analysis of the output reveals that, in most situations, WAPP output is not very sensitive to the difference in altimeter orbit.

Supercavitating torpedoes pose new threats to submarines, surface ships, and shore targets whose current countermeasures are inadequate against this technology. These torpedoes have the advantage over their predecessors and companion weapons of dramatically increased speed, which reduces the reaction time available for deploying a countermeasure heightening the threat to their intended target. Proliferation of supercavitating torpedoes has motivated research on countermeasures against them as well as on the fluid phenomenon which makes them possible. The goal of this research was to investigate an envisaged countermeasure; an acoustic field capable of slowing or diverting the weapon by disrupting the cavitation envelope. The research focused on the interactions between high-level sound signals and a supercavity produced by a small free-flying projectile. In order to conduct this study it was necessary to achieve three preliminary accomplishments involving the design of: 1) experimental apparatus that allowed for the study of a small-scale supercavitating projectile in the laboratory environment; 2) apparatus and software for measuring and recording information about projectile dynamics and supercavity geometry; and 3) an acoustic array and power source capable of focusing the desired sound signal in the path of the supercavitating object. Positive results have been found which show that the accuracy of a supercavitating projectile can indeed be adversely affected by the sound signal. This research concludes with results that indicate that it is acoustic cavitation in the medium surrounding the supercavity that is responsible for the reduced accuracy. A hypothesis has been presented addressing the means by which the acoustic cavitation could cause this effect. Additionally, corrugations on the cavity/water interface imposed by the pressure signal have been observed and characterized.

<p>This work utilized Pointwise and Fluent to generate a two-dimensional axisymmetric model a Mk 48 torpedo, with the intention of informing methods to reduce the turbulence, and therefore hydrodynamic noise, of the torpedo’s wake. However, this work was unable to gather data on the unsteady nature of the turbulence expected around the torpedo due to Fluent providing unrealistic results when run using a transient solver. This work shows that the transient solver computed boundary layers greater than one order of magnitude smaller than expected, and in some cases there was no change in boundary layer thickness over the torpedo’s body. The work does contain steady state solutions that were validated by first performing a grid convergence study for a flat plate. The steady state results for the flat plate and torpedo both showed the expected growth for a turbulent boundary layer. Additionally, there was a high level of convergence with the Log-Law showing that the steady state data is valid. Future work should use a transient solver to determine the characteristics of the turbulence to resolve unsteady flow from vortex shedding, wake characteristics, and any broadband or narrowband noise to develop solutions to reduce the noise made by the Mk 48.</p>