Time-Domain Full-Wave Modeling of Nonlinear Air Breakdown in High-power Microwave Devices and Systems
Abstract
University of Illinois Grant #: FA9451-16-1-0051 “Time-Domain Full-Wave Modeling of Nonlinear Air Breakdown in High-Power Microwave Devices and Systems” Abstract High-power microwave (HPM) devices and systems have very important civilian and military applications. To design better HPM devices that generate higher electromagnetic power and longer pulse width, extensive research effort has been devoted to the development of microwave sources, the design of output windows, and the optimization of advanced cathodes. However, as the power density goes higher and higher, the HPM devices and systems are more and more vulnerable to HPM breakdown, including air breakdown during the generation and transmission of HPM and dielectric window breakdown when the HPM is radiating through the dielectric window. When breakdown happens, the transmission capability of a microwave device can be severely limited. In order to simulate such a multiphysics processes involving field-particle interaction and strong nonlinearity with a high accuracy and reliability, both the electromagnetic physics and the plasma physics have to be described, modelled, and solved accurately. Preliminary research work has been conducted at the University of Illinois at Urbana-Champaign, using a coupled electromagnetic-fluid model in describing the multiscale self-consistent field-plasma physics under atmospheric conditions. A high order nodal discontinuous Galerkin time domain (DGTD) method has been developed for the coupled Maxwell-fluid system, which solves Maxwell’s equations as well as the diffusion-dominated fluid equations. In this research, we propose to develop and investigate the three-dimensional nodal DGTD combined with plasma models to simulate air breakdown problems in HPM devices and systems. We will first study the DGTD formulation of nonlinear problems and investigate its accurate and efficient solution techniques including hp-adaption, local time stepping, and parallelization. We will then investigate a proper model that governs the behavior of the plasma as well as that of the sheath (and the pre-sheath), especially at a high pressure (near atmospheric conditions) and high frequencies (microwave frequency range), including the drift-diffusion equation, the momentum transfer equation with collisions, and the energy conservation equation. Finally we will develop a coupling scheme between the electromagnetic fields and the plasma fluids and adopt an adequate fluid model for investigation and prediction of air breakdown in different scenarios.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 19, 2016
- Source ID
- FA94511610051
Entities
People
- Jian‐Ming Jin
Organizations
- Air Force Research Laboratory
- United States Air Force
- University of Illinois Urbana–Champaign