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Physics (PH)

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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.
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Orginization: Physics (PH) × search.filters.applied.f.isDepartmentOfPublicationVirtual: Physics × Author: Kamada, Ray ×

Publication Search Results

Now showing 1 - 5 of 5
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    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
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    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
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    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.
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    Lompoc Valley Diffusion Experiment Data Report
    (Monterey, California. Naval Postgraduate School, 1990-11-01) Skupniewicz, C. E.; Drake, S. A.; McKay, L.; Abernathy, R. N.; Herr, K. C.; Scherer, G. J.; Guenther, A.; Kamada, Ray; Physics (PH); Graduate School of Operational and Information Sciences (GSOIS); Physics
    A data base representing the results of the Lompoc Valley diffusion experiment is described in detail, outlining formats and defining the contents of the data set. Preliminary analyses are performed, showing concentrations, trajectories and plume widths of a tracer gas plume released from the Hypergolic Stockpile and Storage Facility at Vandenberg Air Force Base, California, and estimating the effects of a potential release of fuel or oxidizer. Future analysis plans are outlined
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    Amending the w* velocity scale for surface layer, entrainment zone, and baroclinic shear in mixed forced/free turbulent convection
    (Monterey, California. Naval Postgraduate School, 1992-03) Kamada, Ray; Physics (PH); Graduate School of Operational and Information Sciences (GSOIS); Physics
    We amend the free convective mixed layer velocity scale, w* to w* s to include mechanical turbulence from forced convection. w* s has discrete surface layer, entrainment zone, and baroclinic components and requires the length scales: zq, L, Ah, z-^, and z^, a newly defined baroclinic length. To close the system we offer simple models for Ah, the entrainment zone depth. The Ah models show realistic diurnal hysteresis, using a critical bulk Richardson number which exceeds unity.