Accession Number : ADA524318


Title :   Hybrid Modeling of Plasma Discharges


Descriptive Note : Final rept. 31 Jul 2002-1 Feb 2010


Corporate Author : AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE


Personal Author(s) : Cambier, Jean-Luc


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a524318.pdf


Report Date : Apr 2010


Pagination or Media Count : 349


Abstract : This document describes the research performed under an AFOSR lab-task started in August 2002, and is still continuing under a different JON. Therefore, this report mostly describes results which are still preliminary. This research is aimed at investigating the difficult problem of hybridization of various physical models and numerical methods in order to more efficiently model complex, non-equilibrium plasma. We are especially interested in plasma conditions which contain a highly energetic component, here restricted to electrons. The general system under study is therefore composed of a bulk, dense fluid (which may contains electrons in equilibrium, i.e. cold) and high-energy particles (hot electrons) which are either injected into the fluid or extracted by the application of high electro-magnetic fields. High-voltage pulsed discharges and laser-plasma are typical examples of such conditions, but these can be also found in subscale regions of other discharges. Because the hot component cannot be described by an equilibrium (Maxwell) distribution, one must combined essentially two numerical approaches: one for the bulk phase (Computational Fluid Dynamics - CFD - in its various formulations), and one for the high-energy component, such as Particle In Cell (PIC) or a discretized phase-space solver (Vlasov or Fokker-Planck). The latter are deemed feasible only for systems with low dimensionality - pending revolutions in computational hardware - but we are interested in eventual application to 3D problems. Thus, PIC remains the method of choice for treatment of this hot component. However, inelastic interactions are of key importance, i.e. excitation and ionization, as well as the reverse processes once the energetic component sufficiently relaxes and cools. The crux of this effort consists of developing and verifying numerical techniques which allow an efficient coupling between these two components.


Descriptors :   *PLASMAS(PHYSICS) , *COMPUTATIONAL FLUID DYNAMICS , *PARTICLE IN CELL , HYBRIDIZATION , ELECTRONS , HIGH ENERGY , PROPELLANTS


Subject Categories : Fluid Mechanics
      Plasma Physics and Magnetohydrodynamics


Distribution Statement : APPROVED FOR PUBLIC RELEASE