Naval Surface Warfare Center

About: Naval Surface Warfare Center is a facility organization based out in Washington D.C., District of Columbia, United States. It is known for research contribution in the topics: Radar & Sonar. The organization has 2855 authors who have published 3697 publications receiving 83518 citations. The organization is also known as: NSWC.

Planning for verification, validation, and accreditation of modeling and simulation applications

Abstract: A comprehensive and detailed verification, validation and accreditation (VV&A) plan and its proper execution are crucially important for the successful accreditation of a modeling and simulation (M&S) application. We provide guidance in developing and executing such a plan throughout the entire M&S application development life cycle. The U.S. Department of Defense (DoD) is the largest sponsor and user of modeling and simulation applications in the world. DoD uses many different types of M&S applications, consisting of a combination of software, hardware, and humanware, under diverse objectives including acquisition, analysis and training.

Smoothness Implies Determinism: A Method to Detect It in Time Series

Abstract: Continuity on an embedded phase space is enough to imply determinism in time series. Also, it is possible to define infinitely many arbitrary vector fields over an attractor. We exploit this arbitrariness to generate a detector of smoothness and therefore of determinism in time series. We report results of numerical studies of both flow and map examples and of a chaotic experimental system.

Optimization of K-shell emission in aluminum z-pinch implosions: Theory versus experiment.

Abstract: Two sets of [ital z]-pinch experiments were recently completed at the Saturn and Phoenix facilities of Sandia National Laboratories and the Naval Surface Warfare Center, respectively, using aluminum wire arrays of different wire and array diameters. Measurements of the total x-ray yield from the [ital K] shell of aluminum were made. In this paper, a comparison of these measurements is made to both theoretical predictions and to a similar set of earlier measurements that were made at the Double Eagle facility of Physics International Company. These three sets of yield measurements have points of agreement with predicted yields and with each other, but they also show points of mutual disagreement, whose significance is discussed. The data are analyzed using a slightly revised version of a previously published [ital K]-shell yield scaling law, and they support the existence of a reasonably well defined region in (load mass)--(implosion velocity) space in which plasma kinetic energy is efficiently converted into [ital K]-shell x rays. Furthermore, a correlation is observed between the inferred conversion efficiencies and the times in which the implosions occur relative to the times when each generator's short-circuit current reaches its peak value. Finally, unlike the Double Eagle experiments, the largestmore » measured yields in the new experiments were observed to occur at the upper velocity boundary of the efficient emission region. Moreover, the observed yields are in fairly good quantitative agreement with an earlier scaling law prediction of the maximum [ital K]-shell x-ray yield from aluminum as a function of load mass assuming kinetic energy conversion alone.« less

First principles calculation of the mechanical compression of two organic molecular crystals.

Abstract: The mechanical compression curves for the organic molecular crystals 1,1-diamino-2,2-dinitroethylene and beta-octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (beta-HMX) are calculated using the Hartree-Fock approximation to the solutions of the many-body Schrodinger equation for a periodic system as implemented in the computer program CRYSTAL. No correction was made for basis set superposition error. The equilibrium lattice parameters are reproduced to within 1% of reported experimental values. Pressure values on the isotherm also agree well with reported experimental values. To obtain accurate results, the relaxation of all the atomic coordinates as well as the lattice parameters under a fixed volume constraint was required.

High-power optical microswitch based on direct fiber actuation

Abstract: An optical microswitch is presented for high-power switching applications. The device, capable of switching several watts of optical power, employs large-core multimode fibers to switch output from a laser diode operating at a wavelength of 810 nm. Switching is achieved through the direct deflection of an on-chip fiber using a high force electrothermal actuator. Optical losses in the system are identified, and optical efficiency is predicted and verified with experimental measurements. The switch demonstrated in this work requires an electrical current of 120 mA and has an electrical power consumption of 5280 mW. The optical efficiency is found to be on the order of 88% (0.55–0.60 dB loss) with a maximum power transfer of 1690 mW from a 1930 mW input. Switching time is 40 ms with channel isolation between the on and off states of 55 dB.