Nonequilibrium Gas and Plasma dynamics group
Encyclopedia
The Nonequilibrium Gas and Plasma Dynamics Laboratory (NGPDL) at the Aerospace Engineering
Department of the University of Michigan
is headed by Professor Iain Boyd and performs research of nonequilibrium gases and plasmas
involving the development of physical models for various gas systems of interest, numerical algorithms on the latest supercomputers, and the application of challenging flows for several exciting projects. The lab places a great deal of emphasis on comparison of simulation with external experimental and theoretical results, having ongoing collaborative studies with colleagues at the University of Michigan
such as the Plasmadynamics and Electric Propulsion Laboratory
, other universities, and government laboratories such as NASA
, United States Air Force Research Laboratory, and the United States Department of Defense
.
Current research areas of the NGPDL include electric propulsion
, hypersonic aerothermodynamics, flows involving very small length scales (MEMS
devices), and materials processing (jets used in deposition thin films for advanced materials). Due to nonequilibrium effects, these flows cannot always be computed accurately with the macroscopic equations of gas dynamics
and plasma physics. Instead, the lab has adopted a microscopic approach in which the atoms/molecules in a gas and the ions/electrons in a plasma are simulated on computationally using a large number of model particles within sophisticated Monte Carlo methods. The lab has developed a general 2D/axi-symmetric/3D code, MONACO, for simulating nonequilibrium neutral flows that can run either on scalar workstations or in a parallel computing
environment.
The lab also has developed a general 2D/axi-symmetic/3D code, LeMANS, to numerically solve the Navier-Stokes equations
using computational fluid dynamics
when the Knudsen number
is sufficiently small. This allows lab members to explore flows that would otherwise be too computationally expensive with a particle method. Work is currently being done to combine the two codes into a hybrid that uses MONACO when the flow is in the collisional nonequilibrium regime and LeMANS when the flow can be considered continuous.
Current and past plasma and nonequilibrium flow projects include simulation of ion thruster
s, Hall effect thruster
s, and pulsed plasma thruster
s) as well as numerous NASA
contracts to study reentry aerothermodynamics for space vehicles, including the Crew Exploration Vehicle
. Other plasma research includes modeling wall ablation from directed energy weapons and the plasma-propellant interaction in electrothermal chemical guns
.
Aerospace engineering
Aerospace engineering is the primary branch of engineering concerned with the design, construction and science of aircraft and spacecraft. It is divided into two major and overlapping branches: aeronautical engineering and astronautical engineering...
Department of the University of Michigan
University of Michigan
The University of Michigan is a public research university located in Ann Arbor, Michigan in the United States. It is the state's oldest university and the flagship campus of the University of Michigan...
is headed by Professor Iain Boyd and performs research of nonequilibrium gases and plasmas
Plasma (physics)
In physics and chemistry, plasma is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms , thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions...
involving the development of physical models for various gas systems of interest, numerical algorithms on the latest supercomputers, and the application of challenging flows for several exciting projects. The lab places a great deal of emphasis on comparison of simulation with external experimental and theoretical results, having ongoing collaborative studies with colleagues at the University of Michigan
University of Michigan
The University of Michigan is a public research university located in Ann Arbor, Michigan in the United States. It is the state's oldest university and the flagship campus of the University of Michigan...
such as the Plasmadynamics and Electric Propulsion Laboratory
Plasmadynamics and Electric Propulsion Laboratory
Plasmadynamics and Electric Propulsion Laboratory is a University of Michigan laboratory facility for electric propulsion and plasma application research. The primary goals of PEPL is to increase efficiency of electric propulsion systems, understand integration issues of plasma thrusters with...
, other universities, and government laboratories such as NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
, United States Air Force Research Laboratory, and the United States Department of Defense
United States Department of Defense
The United States Department of Defense is the U.S...
.
Current research areas of the NGPDL include electric propulsion
Electric propulsion
An electrically powered spacecraft propulsion system is any of a number of forms of electric motors which spacecraft can employ to gain mechanical energy in outer space...
, hypersonic aerothermodynamics, flows involving very small length scales (MEMS
Microelectromechanical systems
Microelectromechanical systems is the technology of very small mechanical devices driven by electricity; it merges at the nano-scale into nanoelectromechanical systems and nanotechnology...
devices), and materials processing (jets used in deposition thin films for advanced materials). Due to nonequilibrium effects, these flows cannot always be computed accurately with the macroscopic equations of gas dynamics
Gas dynamics
Gas dynamics is a branch of fluid dynamics concerned with studying the motion of gases and its consequent effects. Gas dynamics combines the principles of fluid mechanics and thermodynamics...
and plasma physics. Instead, the lab has adopted a microscopic approach in which the atoms/molecules in a gas and the ions/electrons in a plasma are simulated on computationally using a large number of model particles within sophisticated Monte Carlo methods. The lab has developed a general 2D/axi-symmetric/3D code, MONACO, for simulating nonequilibrium neutral flows that can run either on scalar workstations or in a parallel computing
Parallel computing
Parallel computing is a form of computation in which many calculations are carried out simultaneously, operating on the principle that large problems can often be divided into smaller ones, which are then solved concurrently . There are several different forms of parallel computing: bit-level,...
environment.
The lab also has developed a general 2D/axi-symmetic/3D code, LeMANS, to numerically solve the Navier-Stokes equations
Navier-Stokes equations
In physics, the Navier–Stokes equations, named after Claude-Louis Navier and George Gabriel Stokes, describe the motion of fluid substances. These equations arise from applying Newton's second law to fluid motion, together with the assumption that the fluid stress is the sum of a diffusing viscous...
using computational fluid dynamics
Computational fluid dynamics
Computational fluid dynamics, usually abbreviated as CFD, is a branch of fluid mechanics that uses numerical methods and algorithms to solve and analyze problems that involve fluid flows. Computers are used to perform the calculations required to simulate the interaction of liquids and gases with...
when the Knudsen number
Knudsen number
The Knudsen number is a dimensionless number defined as the ratio of the molecular mean free path length to a representative physical length scale. This length scale could be, for example, the radius of a body in a fluid...
is sufficiently small. This allows lab members to explore flows that would otherwise be too computationally expensive with a particle method. Work is currently being done to combine the two codes into a hybrid that uses MONACO when the flow is in the collisional nonequilibrium regime and LeMANS when the flow can be considered continuous.
Current and past plasma and nonequilibrium flow projects include simulation of ion thruster
Ion thruster
An ion thruster is a form of electric propulsion used for spacecraft propulsion that creates thrust by accelerating ions. Ion thrusters are categorized by how they accelerate the ions, using either electrostatic or electromagnetic force. Electrostatic ion thrusters use the Coulomb force and...
s, Hall effect thruster
Hall effect thruster
In spacecraft propulsion, a Hall thruster is a type of ion thruster in which the propellant is accelerated by an electric field. Hall thrusters trap electrons in a magnetic field and then use the electrons to ionize propellant, efficiently accelerate the ions to produce thrust, and neutralize the...
s, and pulsed plasma thruster
Pulsed plasma thruster
Pulsed plasma thrusters are a method of spacecraft propulsion also known as Plasma Jet Engines in general. They use an arc of electric current adjacent to a solid propellant, to produce a quick and repeatable burst of impulse...
s) as well as numerous NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
contracts to study reentry aerothermodynamics for space vehicles, including the Crew Exploration Vehicle
Crew Exploration Vehicle
The Crew Exploration Vehicle was the conceptual component of the U.S. NASA Vision for Space Exploration that later became known as the Orion spacecraft...
. Other plasma research includes modeling wall ablation from directed energy weapons and the plasma-propellant interaction in electrothermal chemical guns
Electrothermal-chemical technology
Electrothermal-chemical technology is an attempt to increase accuracy and muzzle energy of future tank, artillery, and close-in weapon system guns by improving the predictability and rate of expansion of propellants inside the barrel....
.