An implicit Smooth Particle Hydrodynamic code

Abstract

This thesiswas acceptedby the Departmentof Enp"neen"ng, University ofNew Mexico,Albuquerque,<New Mexico,in partialfulfillment of the requirmts for thedegreeofDoctorofPhilosophy.Thetext and illustrationsarethe independent workoftheauthorand only thefront matterhasbeeneditedby the ClC-l Writing and Editing StaJfto conformwith Departmentof Energyand LosAlamosNationalLaboratoy publicationpolicies. An AffirmativeAction/EqualOpportunityEmployer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither The Regents of the University of Cal~omia, the United States Government nor any agency thereo$ nor any of their employees, makes any warranty, eqress or implied, or assumes any legal liability or responsibilityfor the accuracy, completeness, or usefulness ofany information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned n"ghts.Rsj2rence herein to any specific commercial product, process, or service by trade name, tradqark, manufacturer, orothenvise, does not necessan"lyconstitute or imply its endorsement, recommendation, orfavon"ng by The Regents of the University of CaliJomia, the United States Government, or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of The Regents of the University of Cal#omia, the United States Government, or any agency thereof Los Alanws National Lnboratoq strongly supports academicjleedom and a researcher's right topublish; as an institution, however, the Laboratoy does not endorse the vkwpoint of a publication or guarantee its technical correctness.

Conservative, density-based smoothed particle hydrodynamics with improved partition of the unity and better estimation of gradients

“…Solid lines are for the estimator X 1 and lines with points for X 2 . Right: averaged value of L 1 , obtained with expression (25), for the derivative of the wall function calculated with X 1 (solid red line) and X 2 (red line with points). The black line is the calculation with the non-conservative ISPH which is independent of the particular value of the exponent p. Note that when p 1 both schemes (ISPH and ncISPH) converge, albeit faster for estimator X 1 than for X 2 .…”

“…Unlike the indirect methods described in the previous section, a fully implicit implementation of the VEs has the advantage of always leading to the perfect partition of unit. Previous attempts to build implicit SPH schemes [25,26], made use of advanced techniques to efficiently invert large sparse matrices, as for example the PARDISO library 6 . This type of libraries could also be used to implicitly find the volume elements.…”

Magnetized Plasma Target for Plasma-Jet-Driven Magneto-Inertial Fusion

“…where r j0 is the initial jet radius at the chamber wall (where jets are launched), M j the initial jet Mach number, r w the chamber-wall radius, and N the number of jets. Equation (10) assumes that the jet expands both radially and axially at the speed 2C s /(γ − 1). If the jets expand instead at the slower speed C s , which appears to be a better match to experiments [17], then r m,min = r j0 (M j + 1) + r w 1 + 2(M j + 1)/N 1/2 .…”

Possible energy gain for a plasma-liner-driven magneto-inertial fusion concept

“…The geometries for 30 and 60 merging jets have been setup without the radiation and 3-T packages, which is probably not important for the merging of the jets [33]. The code used was a Smooth Particle Hydro (SPH) code called SPHINX.…”