Nonequilibrium Gas and Plasma Dynamics Laboratory

Last updated

The Nonequilibrium Gas and Plasma Dynamics Laboratory (NGPDL) at the Aerospace Engineering Department of the University of Colorado Boulder is headed by Professor Iain D. 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-symmetric/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 thrusters, Hall effect thrusters, and pulsed plasma thrusters) 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.

Official website

https://www.colorado.edu/lab/ngpdl/

Related Research Articles

<span class="mw-page-title-main">Hall-effect thruster</span> Type of electric propulsion system

In spacecraft propulsion, a Hall-effect thruster (HET) is a type of ion thruster in which the propellant is accelerated by an electric field. Hall-effect thrusters are sometimes referred to as Hall thrusters or Hall-current thrusters. Hall-effect thrusters use a magnetic field to limit the electrons' axial motion and then use them to ionize propellant, efficiently accelerate the ions to produce thrust, and neutralize the ions in the plume. The Hall-effect thruster is classed as a moderate specific impulse space propulsion technology and has benefited from considerable theoretical and experimental research since the 1960s.

<span class="mw-page-title-main">Ion thruster</span> Spacecraft engine that generates thrust by generating a jet of ions

An ion thruster, ion drive, or ion engine is a form of electric propulsion used for spacecraft propulsion. It creates thrust by accelerating ions using electricity.

<span class="mw-page-title-main">Magnetic sail</span> Spacecraft propulsion method that takes advantage of solar wind.

A magnetic sail is a proposed method of spacecraft propulsion that uses a static magnetic field to deflect a plasma wind of charged particles radiated by the Sun or a Star thereby transferring momentum to accelerate or decelerate a spacecraft. Most approaches require little to no propellant and thus are a form of Field propulsion. A magnetic sail could also thrust against a planetary ionosphere or magnetosphere. Important use cases are: a modest force from the solar wind sustainable for a long period of time; deceleration in the interstellar medium and the plasma wind of a destination Star following interstellar travel at relativistic speeds achieved by some other means; and efficient deceleration in a planetary ionosphere. Plasma characteristics for the Solar wind, a planetary ionosphere and the interstellar medium and the specifics of the magnetic sail design determine achievable performance; such as, thrust, required power and mass.

<span class="mw-page-title-main">Magnetohydrodynamics</span> Study of electrically conducting fluids

Magnetohydrodynamics is the study of the magnetic properties and behaviour of electrically conducting fluids. Examples of such magneto­fluids include plasmas, liquid metals, salt water, and electrolytes. The word magneto­hydro­dynamics is derived from magneto- meaning magnetic field, hydro- meaning water, and dynamics meaning movement. The field of MHD was initiated by Hannes Alfvén, for which he received the Nobel Prize in Physics in 1970.

<span class="mw-page-title-main">Hypersonic speed</span> Speed that is highly supersonic

In aerodynamics, a hypersonic speed is one that exceeds five times the speed of sound, often stated as starting at speeds of Mach 5 and above.

A discrete element method (DEM), also called a distinct element method, is any of a family of numerical methods for computing the motion and effect of a large number of small particles. Though DEM is very closely related to molecular dynamics, the method is generally distinguished by its inclusion of rotational degrees-of-freedom as well as stateful contact and often complicated geometries. With advances in computing power and numerical algorithms for nearest neighbor sorting, it has become possible to numerically simulate millions of particles on a single processor. Today DEM is becoming widely accepted as an effective method of addressing engineering problems in granular and discontinuous materials, especially in granular flows, powder mechanics, and rock mechanics. DEM has been extended into the Extended Discrete Element Method taking heat transfer, chemical reaction and coupling to CFD and FEM into account.

<span class="mw-page-title-main">Computational fluid dynamics</span> Analysis and solving of problems that involve fluid flows

Computational fluid dynamics (CFD) is a branch of fluid mechanics that uses numerical analysis and data structures to analyze and solve problems that involve fluid flows. Computers are used to perform the calculations required to simulate the free-stream flow of the fluid, and the interaction of the fluid with surfaces defined by boundary conditions. With high-speed supercomputers, better solutions can be achieved, and are often required to solve the largest and most complex problems. Ongoing research yields software that improves the accuracy and speed of complex simulation scenarios such as transonic or turbulent flows. Initial validation of such software is typically performed using experimental apparatus such as wind tunnels. In addition, previously performed analytical or empirical analysis of a particular problem can be used for comparison. A final validation is often performed using full-scale testing, such as flight tests.

The von Karman Institute for Fluid Dynamics (VKI) is a non-profit educational and scientific organization which specializes in three specific fields: aeronautics and aerospace, environment and applied fluid dynamics, turbomachinery and propulsion. Founded in 1956, it is located in Sint-Genesius-Rode, Belgium.

In plasma physics, the particle-in-cell (PIC) method refers to a technique used to solve a certain class of partial differential equations. In this method, individual particles in a Lagrangian frame are tracked in continuous phase space, whereas moments of the distribution such as densities and currents are computed simultaneously on Eulerian (stationary) mesh points.

<span class="mw-page-title-main">Plasmadynamics and Electric Propulsion Laboratory</span> Organization

Plasmadynamics and Electric Propulsion Laboratory (PEPL) 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 spacecraft, and to identify non-propulsion applications of electric propulsion technology. The current director and founder is Professor Alec D. Gallimore.

<span class="mw-page-title-main">Spacecraft electric propulsion</span> Type of space propulsion

Spacecraft electric propulsion is a type of spacecraft propulsion technique that uses electrostatic or electromagnetic fields to accelerate mass to high speed and thus generate thrust to modify the velocity of a spacecraft in orbit. The propulsion system is controlled by power electronics.

<span class="mw-page-title-main">Computational engineering</span>

Computational Engineering is an emerging discipline that deals with the development and application of computational models for engineering. At this time, various different approaches are summarized under the term Computational Engineering, including using computational geometry and virtual design for engineering tasks, often coupled with a simulation-driven approach In Computational Engineering, algorithms solve mathematical and logical models that describe engineering challenges, sometimes coupled with some aspect of AI, specifically Reinforcement Learning.

<span class="mw-page-title-main">VSim</span>

VSim is a cross-platform computational framework for multiphysics, including electrodynamics in the presence of metallic and dielectric shapes as well as with or without self-consistent charged particles and fluids. VSim comes with VSimComposer, a full-featured graphical user interface for visual setup of any simulation, including CAD geometry import and/or direct geometry construction. With VSimComposer, the user can execute data analysis scripts and visualize results in one, two, or three dimensions. VSim computes using the powerful Vorpal computational engine, which has been used to simulate the dynamics of electromagnetic systems, plasmas, and rarefied as well as dense gases. VSim is used for modeling basic electromagnetics and plasma physics, complex metallic and dielectric shapes, photonics, vacuum electronics including multipactor effects, laser wake-field acceleration, plasma thrusters, and fusion plasmas.

The material point method (MPM) is a numerical technique used to simulate the behavior of solids, liquids, gases, and any other continuum material. Especially, it is a robust spatial discretization method for simulating multi-phase (solid-fluid-gas) interactions. In the MPM, a continuum body is described by a number of small Lagrangian elements referred to as 'material points'. These material points are surrounded by a background mesh/grid that is used to calculate terms such as the deformation gradient. Unlike other mesh-based methods like the finite element method, finite volume method or finite difference method, the MPM is not a mesh based method and is instead categorized as a meshless/meshfree or continuum-based particle method, examples of which are smoothed particle hydrodynamics and peridynamics. Despite the presence of a background mesh, the MPM does not encounter the drawbacks of mesh-based methods which makes it a promising and powerful tool in computational mechanics.

A CFD-DEM model is suitable for the modeling or simulation of fluid-solids or fluid-particles systems. In a typical CFD-DEM model, the phase motion of discrete solids or particles is obtained by the Discrete Element Method (DEM) which applies Newton's laws of motion to every particle and the flow of continuum fluid is described by the local averaged Navier–Stokes equations that can be solved by the traditional Computational Fluid Dynamics (CFD). The model is first proposed by Tsuji et al. The interactions between the fluid phase and solids phase is better modeled according to Newton's third law.

<span class="mw-page-title-main">Plasma (physics)</span> State of matter

Plasma is one of four fundamental states of matter, characterized by the presence of a significant portion of charged particles in any combination of ions or electrons. It is the most abundant form of ordinary matter in the universe, being mostly associated with stars, including the Sun. Extending to the rarefied intracluster medium and possibly to intergalactic regions, plasma can be artificially generated by heating a neutral gas or subjecting it to a strong electromagnetic field.

<span class="mw-page-title-main">Computational astrophysics</span> Methods and computing tools developed and used in astrophysics research

Computational astrophysics refers to the methods and computing tools developed and used in astrophysics research. Like computational chemistry or computational physics, it is both a specific branch of theoretical astrophysics and an interdisciplinary field relying on computer science, mathematics, and wider physics. Computational astrophysics is most often studied through an applied mathematics or astrophysics programme at PhD level.

The following timeline starts with the invention of the modern computer in the late interwar period.

<span class="mw-page-title-main">Elaine Oran</span> American aerospace engineer, computer scientist, physicist

Elaine Surick Oran is an American physical scientist and is considered a world authority on numerical methods for large-scale simulation of physical systems. She has pioneered computational technology to solve complex reactive flow problems, unifying concepts from science, mathematics, engineering, and computer science in a new methodology. An incredibly diverse range of phenomena can be modeled and better understood using her techniques for numerical simulation of fluid flows, ranging from the tightly grouped movements of fish in Earth's oceans to the explosions of far-flung supernovae in space. Her work has contributed significantly to the advancement of the engineering profession.

The Institute of Mathematical Problems of Biology RAS is a research institute specializing in computational biology and bioinformatics. The objective of the institute is elaboration of mathematical and computational methods for biological research, as well as implementation of these methods directly addressing the problems of computational biology.