Organization:
Physics (PH)

Description

The mission of the Physics Department is to provide defense-relevant, advanced education and research programs to meet Naval unique needs, and increase the warfighting effectiveness of the U.S. Naval Forces, DoD and allied armed forces.

Website of the organization

https://nps.edu/web/physics

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Now showing 1 - 10 of 22

Lompoc Valley Diffusion Experiment analysis - Mt. Iron comparison and two zone convective scaling model
(Monterey, California. Naval Postgraduate School, 1992-01) Skupniewicz, C.E.; Kamada, Ray; Drake, S.A.; Physics (PH); Graduate School of Operational and Information Sciences (GSOIS); Physics
LVDE(Lompoc Valley Diffusion Experiment) was conducted Aug 1989 to assess the potential risk of gaseous releases from the Hypergolic Stockpile and Storage Facility at Vandenberg AFB. Results of the LVDE are compared to the predictive equations of the Mt. Iron Diffusion Tests, conducted at Vandenberg in the 1960's. The Mt. Iron equation parameterizes diffusion with on-base meteorological tower input data. Regression techniques similar to those of Mt. Iron are used in this comparison, resulting in LVDE equations which use the same meteorological data as input. Instantaneous and time averaged centerline concentrations, in both flat and complex terrain are analyzed. For all cases LVDE concentrations are shown to decrease with range less rapidly than the Mt. Iron equation predicts. We suggest that this bias is due to gravitational and/or scavenging losses of the tracer material used in Mt. Iron. A 'two-zone' convective scaling equation is developed which diffuses the plume differently in cloud covered and clear sky portions of the domain. The method is shown to be superior to homogeneous convective scaling equations, and comparable to a statistical approach based on the plume measurements. While the method works for maximum concentration predictions, it fails for plume width and crosswind integrated concentration for X > 6
Basic Research in Thermoacoustic Heat Transport
(Monterey, California. Naval Postgraduate School, 1996-06-11) Atchley, Anthony A.; Physics (PH); Graduate School of Operational and Information Sciences (GSOIS); Physics
This technical report details progress in basic research in thermoacoustic heat transport made during the period June 1, 1995 through May 30, 1996. Research efforts were primarily concentrated in three areas: 1) investigation of fundamental limitations to the performance of thermoacoustic devices; 2) design, construction, and demonstration of a proof-of-concept, shipboard, heat driven thermoacoustic cooler capable of cooling loads of 1 kW; 3) measurement of transient effects in thermoacoustic devices to provide data to test nonlinear, timedependent models of thermoacoustics. Accomplishments include 1) the design of a prototype toroidal prime mover; 2) preliminary measurements of the temperature evolution along a stack in a mechanically driven configuration; 3) preliminary measurements of transient effects in prime movers; 4) preliminary design of a new prime mover configuration; and 5) fabrication of a 1 kVV heat driven cooler. A publications, patents, presentations, and honors report is also included.
Sea test development of laser altimeter
(Monterey, California. Naval Postgraduate School, 1991-01) Crittenden, Eugene Casson; Rodeback, George Wayne; Milne, Edmund Alexander; Cooper, Alfred William; Physics (PH); Graduate School of Operational and Information Sciences (GSOIS); Physics
Low altitude (81 m.) narrow-beam laser reflectance measurements were made from the nearly ocean-like water surface under the Golden Gate bridge. This site allowed precise measurements not possible from flying platforms. For short wavelength water waves superimposed on swell, the signal amplitude probability distribution showed periods of zero return signal, even for vertical incidence, apparently due to tipping of the average water surface. The nonzero signals show an antilog-normal probability distribution, skewed toward higher signal than that provided by a normal (Gaussian) distribution. With incidence angle displaced from the vertical, the distribution shape is retained but with more frequent zero reflections. The decrease with angle of the average signal, including the zeroes, is well fitted with a Gram-Charlier distribution, as seen by earlier observers using photographic techniques which masked these details of the structure. For the simpler wave pattern due to a long sustained wind direction, the signal amplitude probability distribution is lognormal with no zero signal periods. For this case, the distribution shifts toward exponential at large angles from the vertical. For surface states intermediate between the above two extremes the distribution is often normal. The larger return signals resulting from the skew toward larger amplitudes from lognormal are more favorable for disposable laser altimeters than previously believed. Also for an altimeter which may be swinging from a parachute or balloon, the return at angles from the vertical remains high. The presence of occasional zero return signal does degrade the accuracy of altitude somewhat for a descending altimeter, but the signal available assures performance at larger altitudes than previously expected.
Annual Summary of Basic Research in Thermoacoustic Heat Transport: 1990
(Monterey, California. Naval Postgraduate School, 1990-10) Atchley, Anthony Amstrong; Hofler, Thomas James; Physics (PH); Graduate School of Operational and Information Sciences (GSOIS); Physics
A comparison of eight cases selected from the vandenberg AFB Mt. Iron tracer study with results from the Lincoln/Rimpuff dispersion model
(Monterey, California. Naval Postgraduate School, 1991-12) Kamada, Ray; Physics (PH); Graduate School of Operational and Information Sciences (GSOIS); Physics
Wave turbulence and soliton dynamics
(Monterey, California. Naval Postgraduate School, 1992-04) Keolian, Robert M.; Physics (PH); Graduate School of Operational and Information Sciences (GSOIS); Physics
Work in three areas is summarized in this report. 1) Two new localized structures were experimentally discovered in vibrating lattices and were described theoretically with a nonlinear Schrodinger eguation. One is a domain wall between different types of vibration, the other is a kink in the phase of vibration. The kink has also been discovered in parametrically driven surface waves on water. 2) The direction and spectral energy of interacting nonlinear ocean waves evolve as they approach a sloping beach. A first principles theory was developed for this process and it was shown to agree with ocean experiments. 3) Experiments to determine whether random interacting waves on the ocean move collectively, having average quantities analogous to "pressure" in a gas as well as collective modes of vibration, are described.
Atmospheric optical turbulence measurements taken at Anderson Mesa, Flagstaff, Arizona between 10-19 July 1990
(Monterey, California. Naval Postgraduate School, 1991-01) Vaucher, Gail M. Tirrell; Vaucher, Christopher A.; Walters, Donald L.; Physics (PH); Graduate School of Operational and Information Sciences (GSOIS); Physics
From 10 to 19 July 1990, the Naval Postgraduate School Atmospheric Optics Group acquired atmospheric optical turbulence measurements at the 13-inch Lowell Observatory astrographic telescope dome on Anderson Mesa, 16 km southeast of Flagstaff, Arizona. This collection of transverse coherence lengths and isoplanatic angles was the last in a three part Anderson Mesa site-survey measurement set for a large-scale, ground-based, synthetic aperture system (100- 300 m baseline stellar interferometer). The intent of this report is to compile, analyze and summarize the acquired optical data, as well as correlate the meteorological and optical conditions present during the data acquisitions
A Theatre Ballistic Missile (TBM) Counterforce Concept
(Monterey, California. Naval Postgraduate School, 1993-12) Berhow, Todd, J.; Buckingham, William Morgan; Day, John; Davis, Jeff; Hill, Jon; Nessler, F. Scot; Wolfe, Johnny.; Physics (PH); Graduate School of Operational and Information Sciences (GSOIS); Physics
The purpose of this report is to first give a fairly comprehensive list of the world's tactical ballistic missile systems and then to discuss some of the options available to find the TBM's before they can be launched. The focus of this report is primarily on finding the Transported Erector Launchers by the use of unattended ground sensors.
Chaos Metrics for Testing Lagrangian Particle Models
(Monterey, California. Naval Postgraduate School, 1993-01-31) Kamada, Ray; Physics (PH); Graduate School of Operational and Information Sciences (GSOIS); Physics
The Lorenz and Henon attractors and two atmospheric Lagrangian particle models were tested using self-affine fractal dimension, DA, Shannon information entropy, S, and the Lyapunov exponent, lambda, along with turbulent kinetic energy, vertical variance, and Brunt-Vaisala Frequency. Results show that (1) chaos metrics are a new set of tools to assess the micro behavior of Lagrangian particle models, (2) that periodicity in bifurcatory systems differs from wave behavior in fluids, since wave states are not limited to amplitude extrema. (3) Non-spectral particle models lead to unrealistic variations in 'the chaos metrics with changes in buoyant stability. (4) S and DA behave oppositely at times, implying that diffusion and dispersion are not equivalent, even in the absence of mean windflow.
On the use of sympathetic resonators to improve low-frequency underwater transducer performance
(Monterey, California. Naval Postgraduate School, 1991-10) Baker, Steven R.; Ellsworth, John Merle; Physics (PH); Graduate School of Operational and Information Sciences (GSOIS); Physics
The achievable gain in the radiation resistance and directivity of a low-frequency underwater transducer due to the presence of an array of sympathetic resonators has been analyzed. The resonators were all taken to be air bubbles, and both the resonators and transducer were taken to be compact (ka << 1). The resonators were taken to be equally spaced around a circle of radius R, with the transducer located on the axis. The gain was calculated for various numbers of resonators as a function of ka(resonator), ka(transducer) and kR, for the transducer in the plane of the resonators and out of the plane a distance of one-quarter wavelength. For the transducer in the plane, a gain in radiation resistance of approximately two is possible with six or more resonators. For the transducer out of the plane, it is shown that a front-to-back discrimination of approximately 8 dB can be achieved, at the expense of a decrease of approximately ten percent in the achievable gain in the radiation resistance, compared to the transducer in the plane of the resonators