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Ionization coefficient approach to modeling breakdown in nonuniform geometries.

Description: This report summarizes the work on breakdown modeling in nonuniform geometries by the ionization coefficient approach. Included are: (1) fits to primary and secondary ionization coefficients used in the modeling; (2) analytical test cases for sphere-to-sphere, wire-to-wire, corner, coaxial, and rod-to-plane geometries; a compilation of experimental data with source references; comparisons between code results, test case results, and experimental data. A simple criterion is proposed to differentiate between corona and spark. The effect of a dielectric surface on avalanche growth is examined by means of Monte Carlo simulations. The presence of a clean dry surface does not appear to enhance growth.
Date: November 1, 2003
Creator: Warne, Larry Kevin; Jorgenson, Roy Eberhardt & Nicolaysen, Scott D.
Partner: UNT Libraries Government Documents Department

Capacitance and effective area of flush monopole probes.

Description: Approximate formulas are constructed and numerical simulations are carried out for electric field derivative probes that have the form of flush mounted monopoles. Effects such as rounded edges are included. A method is introduced to make results from two-dimensional conformal mapping analyses accurately apply to the three-dimensional axisymmetric probe geometry
Date: August 1, 2004
Creator: Warne, Larry Kevin; Johnson, William Arthur; Morris, Marvin E.; Basilio, Lorena I.; Lehr, Jane Marie & Higgins, Matthew B.
Partner: UNT Libraries Government Documents Department

The verdict geometric quality library.

Description: Verdict is a collection of subroutines for evaluating the geometric qualities of triangles, quadrilaterals, tetrahedra, and hexahedra using a variety of metrics. A metric is a real number assigned to one of these shapes depending on its particular vertex coordinates. These metrics are used to evaluate the input to finite element, finite volume, boundary element, and other types of solvers that approximate the solution to partial differential equations defined over regions of space. The geometric qualities of these regions is usually strongly tied to the accuracy these solvers are able to obtain in their approximations. The subroutines are written in C++ and have a simple C interface. Each metric may be evaluated individually or in combination. When multiple metrics are evaluated at once, they share common calculations to lower the cost of the evaluation.
Date: March 1, 2006
Creator: Knupp, Patrick Michael; Ernst, C.D. (Elemental Technologies, Inc., American Fork, UT); Thompson, David C. (Sandia National Laboratories, Livermore, CA); Stimpson, C.J. (Elemental Technologies, Inc., American Fork, UT) & Pebay, Philippe Pierre
Partner: UNT Libraries Government Documents Department