Cold relativistic ideal magnetohydrodynamic (MHD) flows are studied in the stationary and axisymmetric magnetosphere of a rapidly rotating compact object. To obtain highly accelerated winds, MHD winds emanating from a geometrically thin disk and passing t...
National Technical Information Service (NTIS)
The ideal MHD equations are reduced to a single equation under the assumption of axisymmetric flow. A variational principle from which the equation is derivable is given. The characteristics of the equation are briefly discussed. The equation is used to rederive the theorem of Gussenhoven and Carovillano.
Energy Citations Database
The present work attempts to formulate the equilibrium of axisymmetric plasma with purely toroidal flow within ideal MHD theory. In general, the inertial term Rho(v.Del)v caused by plasma flow is so complicated that the equilibrium equation is completely ...
Axisymmetric, ideal MHD configurations with steady flow are computed by applying the finite element method. Rectangular elements with four to eight nodes are used. By mesh rearrangement the equilibria are obtained in flux coordinates. Accurate results wit...
Energy of eigenmodes in magnetohydrodynamic (MHD) flows of ideal fluids is studied analytically. It is shown that the energy of unstable modes is zero, while the energy of stable oscillatory modes (waves) can assume both positive and negative values. Negative energy waves always correspond to eigenmodes with a finite component of the ...
NASA Astrophysics Data System (ADS)
The motivation of this study is to gain additional understanding of the effect of rotation on the equilibrium of a plasma. The axisymmetric equilibria of ideal magnetohydrodynamics (MHD) with flow have been studied numerically and analytically. A general ...
case where the interplanetary field is oriented transverse to the flow. In order to self- ...... term derived from ideal MHD equations, which tends to ...
NASA Website
Unsteady reconnection in skewed fields under the finite length of X-line is considered in the frame of ideal incompressible MHD approximation. The propagation of discontinuities as well as the evolution of magnetic field, plasma flow and pressure are comp...
The well-posedness of the equations of fluid mechanics in the hydrostatic limit is well known to be a difficult problem. Partial results, both positive and negative, will be reviewed below. In this paper, it is shown that, for ideal magnetohydrodynamics, a magnetic field parallel to the flow direction can ensure well-posedness. The only condition required ...
A numerical investigation was made of flow in the channel of an MHD generator with solid and ideally sectionalized electrodes with application to large-scale MHD generators. The fields of the gasdynamic and electrical parameters are found. The volt: ampere and load characteristics of the work of the generator are ...
Applications of magnetohydrodynamic (MHD) accelerator for advanced propulsion has been proposed. The Magnetohydrodynamic Augmented Propulsion Experiment (MAPX) that has diagonal connected MHD accelerator is planned by NASA Marshall Space Flight Center. The diagonal accelerator with suitable electrode connections can achieve the condition that the current ...
The Parker problem in Hall magnetohydrodynamics (MHD) is considered. Poloidal shear superposed on the toroidal ion flow associated with the Hall effect is incorporated. This is found to lead to a triple deck structure for the Parker problem in Hall MHD, with the magnetic field falling off in the intermediate Hall-resistive region more ...
Parker problem in Hall magnetohydrodynamics (MHD) is considered [1]. Poloidal shear into the toroidal flow generated by the Hall effect is incorporated. This is found to lead to a triple deck structure for the Parker problem in Hall MHD, with the magnetic field falling off in the intermediate Hall- resistive region more steeply (like ...
Laboratory astrophysics holds great promise not only as a highly effective validation tool for astrophysical magneto-hydrodynamics (MHD) codes but it also presents a unique challenge for these codes. The high-density plasmas found in these experiments are not well modeled by the ideal equations of state (EOS) found in most astrophysical simulation codes. ...
beyond ideal MHD and to improve the efficiency of the numerical schemes. ... finished the multi-ion MHD implementation and published a paper ...
Eigenmode analysis of ideal magnetohydrodynamic (MHD) systems with flows is performed. It is shown that the energy of stable oscillatory modes (waves) can be both positive and negative. Negative energy waves always correspond to non-symmetric modes which are nonuniform along the direction of the flow. Coupling of ...
Effects of a sheared toroidal rotation are investigated numerically on the stability of the MHD modes in the tokamak edge pedestal, which relate to the type-I edge-localized mode. A linear MHD stability code MINERVA is newly developed for solving the Frieman-Rotenberg equation that is the linear ideal MHD equation ...
The two-dimensional MHD-flow of the ideal plasma in a channel of the magnetoplasma compressor (MPC) with an axial hole in the central electrode (divertor) is numerically simulated. The steady-state regime of the flow is obtained. The influence of finite and periodical density perturbation at the entry of the channel on the ...
Interaction of a parallel fast MHD shock with a layer of decreased density is discussed using ideal MHD approach. This is an extrapolation of gas dynamic �thermal layer� effect on ideal MHD. Computer simulations show that a magnetic field of a moderate intensity ( ? � 1) may change the ...
A global normal mode stability analysis on the effect of radially sheared azimuthal flow and radially sheared magnetic fields on magnetohydrodynamic (MHD) instabilities in Z-pinch plasmas is presented. A linearized set of ideal MHD equations allows the investigation of plasmas with both magnetic shear and ...
for all surface perturbations during times typical for the jet breakup at zero magnetic #12;eld. 1 target including MHD e#11;ects and showed that magnetic #12;eld signi#12;cantly decreases surface instabilities cm long and 1 cm diameter ideal cylinder with no surface perturbations. The in uence of the proton
E-print Network
The required type and amount of numerical dissipation/filter to accurately resolve all relevant multiscales of complex MHD unsteady high-speed shock/shear/turbulence/combustion problems are not only physical problem dependent, but also vary from one flow ...
The FLASH code developed at the University of Chicago Flash Center is a modular, general-purpose, adaptive, parallel simulation code capable of handling compressible flow problems in various physical, in particular astrophysical, environments. Starting with version release 2.0, the FLASH code supports the equations of magnetohydrodynamics (MHD). In this ...
... Title : MHD Control for Scramjet Inlet. ... Abstract : The potentialities of MHD effect for flow control in a scramjet inlet are discussed. ...
DTIC Science & Technology
The interaction of an imploding plasma-vacuum boundary (PVB) with a collisionless Z pinch for the case where the ions have orbits comparable to the radius is studied. Two principal results are found. First, the development of sheared axial ion flow occurs as a result of large Larmor radius (LLR) ions interacting with the moving PVB. This contrasts strongly with the equivalent ...
The Chew--Goldberger--Low (CGL) double adiabatic model (Proc. R. Soc. London Ser. A 236, 112 (1956)) is used to study the linear m = 0 (sausage) mode in a Z pinch operating in the collisionless, small ion Larmor radius regime. The model is valid in this case since the parallel heat flow is identically zero. A necessary and sufficient condition for stability, applicable to ...
We have just considered three examples of MHD equilibria in cylindrical geometry. These were the ? -pinch, the z-pinch, and the screw pinch. In all of these cases, the cylinder was considered to be infinitely long. In practice, or course, a cylinder must have finite length. The achievement of MHD equilibrium was possible because, in ...
A 3-D parallel adaptive mesh refinement (AMR) scheme is described for solving the partial-differential equations governing ideal magnetohydrodynamic (MHD) flows. This new algorithm adopts a cell-centered upwind finite-volume discretization procedure and uses limited solution reconstruction, approximate Riemann solvers, and explicit ...
compressible ideal MHD is studied numericaIly for a one-fluid non-ideal MHD model. The .... and redundant multiresolution wavelets (WAV) (for all types ...
An understanding of the plasma physics problem of MHD flow around a magnetized sphere or cylinder in
NASA Technical Reports Server (NTRS)
... for MHD Power Generation and ... GAS DISCHARGES), (*MAGNETOHYDR ODYNAMIC GENERATORS ... ELECTRIC POWER PRODUCTION AND ...
Incompressible stationary flows of ideal plasma are studied. By introduction of curvilinear system of coordinates in which streamlines and magnetic force lines form a family of coordinate surfaces, MHD equations are partially integrated and brought to a certain convenient form. It is demonstrated that the admissible group of ...
We investigate numerically the dynamics of two-dimensional Euler and ideal magnetohydrodynamics (MHD) flows in systems with a finite number of modes, up to 4096^{2}, for which several quadratic invariants are preserved by the truncation and the statistical equilibria are known. Initial conditions are the Orszag-Tang vortex with a ...
PubMed
We investigate numerically the dynamics of two-dimensional Euler and ideal magnetohydrodynamics (MHD) flows in systems with a finite number of modes, up to 40962, for which several quadratic invariants are preserved by the truncation and the statistical equilibria are known. Initial conditions are the Orszag-Tang vortex with a neutral ...
Equations of magnetohydrodynamics (MHD) in the natural curvilinear system of coordinates where trajectories and magnetic lines play a role of coordinate curves are reduced to the non-linear vector wave equation coupled with the incompressibility condition in the form of the generalized Cauchy integral. The symmetry group of obtained equation, equivalence transformation, and ...
We use a 2-D) resistive MHD code to simulate an EML plasma armature. The energy equation includes Ohmic heating, radiation heat transport and the ideal gas equation of state, allowing for variable ionization using the Saha equations. We calculate rail ablation taking into account the flow of heat into the interior of the rails. Our ...
Context. Helicity is a fundamental property of magnetic fields, conserved in ideal MHD. In flux rope
The laminar flow of a incompressible viscous conducting liquid in the channel of a MHD pump is studied theoretically. (AIP)
This handbook tells the casual user how to run the program MHD2V106, a computer program to determine linear growth rates and eigenmodes for an ideal MHD plasma in a cylinder or toroid of rectangular cross section.
DOE Information Bridge
radius with a coaxial accelerator coupled to a pinch assembly chamber. Magnetic probes measure linearized, ideal MHD theory to reveal that a sheared axial flow stabilizes the kink mode when the shear the fluctuation levels of the azimuthal modes m = 1, 2, and 3. After assembly the plasma is magnetically confined
A numerical procedure based on a five-wave MHD model associated with non-ideal, low magnetic Reynolds number MHD flows was developed in the present study for analyzing the flow fields in the MHD generator of a MHD bypass scramjet. The numerical ...
We have just derived the �complete� MHD fluid model. We now consider briefly a simpler model that is obtained by ignoring ? and q and setting ? = 0. (Note that this is a form of closure.) The medium is thus a perfect electrical conductor and has no viscosity or thermal conductivity. This is a highly idealized situation, not attainable in nature; it is ...
An ideal magnetohydrodynamics (MHD) equilibrium is described by a system of rather complicated singular differential equations when a flow is included. The so-called Alfven singularity occurs at the place where the Doppler-shifted Alfven velocity vanishes. It is due to the vanishing of the highest-order derivative in the differential ...
A linear stability analysis on the magnetohydrodynamic (MHD) kink instability in Z-pinch plasmas is presented. We use a set of equations based on the Hall fluid model, which allows the investigation of the influence of non-ideal MHD effects on the development of the kink instability in Z-pinch plasmas. These equations have been used to ...
The cylindrical ideal magnetohydrodynamic (MHD) stability problem, including ow and a resistive wall, is cast in the standard mathematical form, ?A?x = B?x, without discretizing the vacuum regions surrounding the plasma. This is accomplished by means of a finite element expansion for the plasma perturbations, by coupling the plasma surface perturbations to ...
The cylindrical ideal magnetohydrodynamic (MHD) stability problem, including ow and a resistive wall, is cast in the standard mathematical form, �A�x = B�x, without discretizing the vacuum regions surrounding the plasma. This is accomplished by means of a finite element expansion for the plasma perturbations, by coupling the plasma surface ...
The generalized Hall effect (GHE) in the generalized Hall model (GHM) is studied as a correction to ideal magnetohydrodynamics (MHD) in the context of how it affects the linear stability of cylindrically symmetric equilibria and how it changes helically symmetric equilibria. The GHM differs from what is usually called the Hall model by including the ...
Recent progress in the development of a class of low dissipative high order (fourth-order or higher) filter schemes for multiscale Navier Stokes, and ideal and non-ideal magnetohydrodynamics (MHD) systems is described. The four main features of this class of schemes are: (a) multiresolution wavelet decomposition of the computed ...
Recent progress in the development of a class of low dissipative high order filter schemes for multiscale Navier-Stokes, and ideal and non-ideal magnetohydrodynamics (MHD) systems is described. The four main features of this schemes are: (a) multiresolution wavelet decomposition of the computed flow data as ...
Toroidal flow velocities of the order of the local sound speed and poloidal flows exceeding theoretical predictions have been observed in several tokamaks. Steady toroidal and poloidal flow effects are studied using dissipationless single-fluid and two-fluid theory, with electron inertia neglected in the latter case. An exact analytic ...
Contents: Similarity solutions for magnetogasdynamic diffuser and confuser flows with viscous, ohmic and thermal dissipation; Similarity theory for compressible gas flow in a cone with viscous and thermal dissipation; MHD stability of the flow in a cylind...
Accretion disks are three-dimensional, turbulent, often self-gravitating, magnetohydrodynamic (MHD) flows, which can be modeled with numerical simulations. In this paper, we present a new algorithm that is based on a spectral decomposition method to simulate such flows. Because of the high order of the method, we can solve the ...
We present a novel approach to the mathematical analysis and computational simulation of fully three-dimensional, nonlinear, viscous, incompressible MHD flow in complex configurations involving several liquid and solid conductors. Such configurations arise in numerous metallurgical processes. Employing the current density rather than the magnetic field as ...
MHD system Discontinuous Galerkin approximation Numerical results Numerical approximation of the ideal MHD M. Gutnic1 P. Helluy1 J.-M. H�rard2 H. Mathis1 E. Sonnendr�cker1 1IRMA, Universit� de Strasbourg 2EDF Paris February 11, 2009 GHHMS Numerical approximation of the ideal MHD ...
A survey of MHD stability limits has been made to address issues arising from the MHD--poloidal field design task of the US ITER project. This is a summary report on the results obtained to date. The study evaluates the dependence of ballooning, Mercier and low-n ideal linear MHD stability on key system parameters ...
Two magnetohydrodynamic (MHD) instabilities are studied. A simple sufficient condition is given for the linear ideal instability of plane parallel equilibria with antisymmetric shear flow and symmetric or antisymmetric magnetic field. Application of this condition demonstrates the destabilizing effect of the magnetic field on shear ...
The motivation of this study is to gain additional understanding of the effect of rotation on the equilibrium of a plasma. The axisymmetric equilibria of ideal magnetohydrodynamics (MHD) with flow have been studied numerically and analytically. A general discussion is provided of previous work on plasmas with flow ...
The linear magnetohydrodynamic (MHD) stability of ideal and resistive, axisymmetric toroidal equilibria is investigated with respect to various physical effects, such as differential toroidal rotation, viscosity, ideal and resistive external walls and current holes. For this purpose, the CASTOR code has been comprehensively extended. ...
Stability properties of an Extrap with N conductors are investigated. The plasma is described by the ideal MHD model, the surface current model is used and the noncircularity is assumed to be weak. The investigation is carried out to second order in a sma...
Page 1. MHD Control for Scramjet Inlet EG Sheikin, AL Kuranov ... The potentialities of MHD effect for flow control in a scramjet inlet are discussed ...
Resistive MHD equilibrium, even for small resistivity, differs greatly from ideal equilibrium, as do the dynamical consequences of its instabilities. The requirement, imposed by Faraday`s law, that time independent magnetic fields imply curl-free electric fields, greatly restricts the electric fields allowed inside a finite-resistivity plasma. If there is ...
The equations of magnetohydrodynamics (MHD) of an ideal fluid have two families of topological invariants: the magnetic helicity invariants and the cross-helicity invariants. It is first shown that these invariants define a natural foliation (described as isomagnetovortical, or imv for short) in the function space in which solutions {u(x, t), h(x, ...
Ambipolar diffusion (AD) is a key process in molecular clouds (MCs). Non-ideal MHD turbulence simulations are technically very challenging because of the large Alfv�n speed of ions in weakly ionized clouds. Using the Heavy-Ion Approximation method (Li, McKee & Klein 2006), we have carried out two-fluid simulations of AD in isothermal, turbulent boxes ...
... Accession Number : ADA458308. Title : Shock Control and Power Extraction by MHD Processes in Hypersonic Air Flow. ...
... Title : RESEARCH IN MHD POWER GENERATION. ... (5) Theoretical studies of metastable ionization and magnetohydrodynamic flows under the ...
... For the MHD solver, option is provided to solve either the full MHD equations or the low magnetic Reynolds number equations. ...
It is well established now that the solar atmosphere, from the photosphere to the corona and the solar wind, is a highly structured medium. Satellite observations have confirmed the presence of steady flows there. Here, we investigate the propagation of magnetohydrodynamic (MHD) eigenmodes (kink and sausage surface waves) travelling along an ...
A new derivation of reduced magnetohydrodynamic (MHD) equations is presented. A multiple-time-scale expansion is employed. It has the advantage of clearly separating the three time scales of the problem associated with (1) MHD equilibrium, (2) fluctuations whose wave vector is aligned perpendicular to the magnetic field, and (3) those aligned parallel to ...
. The present paper considers resonant slow waves in 1D non-uniform magnetic flux tubes in dissipative MHD. Analytical solutions are obtained for the Lagrangian displacement and the Eulerian perturbation of the total pressure for both static and stationary equilibrium states. From these analytical solutions we obtain the fundamental conservation law and the jump conditions ...
... Title : Two-Phase Hartmann Flows in the MHD Generator Configuration. ... equations which are similar to equations describing a steady flow of a ...
... Accession Number : ADA456411. Title : MHD Flow Control and Power Generation in Low-Temperature Supersonic Flows. ...
The first volume of this conference on magnetohydrodynamics (MHD) for electrical power generation covers: (1) MHD pilot plants; (2) MHD generator experiments and modeling; (3) the performance of various MHD generator types; (4) MHD channel design considerations; (5) MHD ...
Steady states are studied in the framework of the ideal Hall magnetohydrodynamics (HMHD) model in arbitrary and axisymmetric geometries. In arbitrary geometry, conditions are found under which certain magnetohydrodynamics (MHD) equilibrium solutions can also satisfy the HMHD equations. For axisymmetric plasmas reduced equations are derived for uniform ...
An MHD equilibrium code (SELENE) and a stability code (ERATO-J) are extensively used for the analysis of ideal MHD beta limit of a tokamak plasma. High efficiency is required for the analysis of experimental data and the design of the next step fusion exp...
Based on the ideal-MHD model the stability of ballooning modes is investigated by employing realistic 3D magnetospheric equilibria, in particular for the substorm growth phase. Previous MHD ballooning stability calculations making use of approximations on...
�We use the 3 D BATS-R-US MHD code described in Roussev et al. (2003, 2004) ... �This code solves the full time-dependent set of the non-linear ideal MHD ...
There is a growing recognition that magnetic fields play a dominant role in driving and collimating astrophysical jets. Using exact semianalytic solutions of the special-relativistic ideal-MHD equations, it is demonstrated that a strongly magnetized accretion disk (with a dominant poloidal or azimuthal magnetic field) around a black hole can efficiently accelerate a ...
Practical and theoretical problems in the industrial-scale conversion of thermal energy to electrical power by the MHD processes are discussed in a review (originally published in Russian in 1983) comprising individual chapters by Soviet MHD experts. Chapters are devoted to engineering and technical problems of developing MHD power ...
In a cylindrical plasma, tearing modes can be calculated by asymptotic matching of ideal mhd solutions across a critical layer. This requires a quantity (Delta)(prime) which represents the 'discontinuity' in the ideal solution across the layer. In a torus...
A numerical study of the free-boundary axisymmetric (n=0) ideal magnetohydrodynamical (MHD) motions of the Extrap device is presented. The dependence of stability on current profiles in the plasma and currents in the external conductors is investigated. R...
The role of shear in determining the ideal MHD stability properties of tokamaks is discussed. In particular, we assess the effects of low shear within the plasma upon pressure-driven modes. The standard ballooning theory is shown to break down, as the she...
A scalar form of the ideal MHD energy principle is shown to provide a more accurate and efficient numerical method for determining the stability of an axisymmetric toroidal equilibrium than the usual vector form. Additional improvement is obtained by empl...
Analytic solutions are constructed of the ideal MHD equations describing the equilibrium of a toroidal plasma with an elliptic cross-section and surrounded by vacuum. The method used is a series expansion in the inverse aspect ratio. Toroidal effects are ...
In order to describe a steady-state plasma equilibrium in tokamaks, stellarators or other non-axisymmetric configurations, the model of ideal MHD with isotropic plasma pressure is widely used. The ideal MHD - model of a toroidal plasma equilibrium require...
The variational problem of an ideal one-dimensional MHD stability is treated by the method of Ritz-Galerkin. Finite elements are taken as the basic functions. In order to find the best approximating elements a radius dependent transformation was performed...
A reduced set of ideal MHD equations is derived for large aspect ratio, low ..beta.. tokamaks that adequately describes the linear and nonlinear evolution of ideal internal kink modes in tokamaks.
A gas-kinetic solver is developed for the ideal magnetohydrodynamics (MHD) equations. The new scheme
... Helicity is a fundamental property of magnetic fields, conserved in ideal MHD. In flux rope topology, it consists of twist and writhe helicity. ...
... ADP014999 TITLE: Hall-MHD Surface Waves in Flowing Solar-Wind Plasma Slab ... Hall-MHD surface waves in flowing solar-wind plasma slab ...
We propose two sets of initial conditions for magnetohydrodynamics (MHD) in which both the velocity and the magnetic fields have spatial symmetries that are preserved by the dynamical equations as the system evolves. When implemented numerically they allow for substantial savings in CPU time and memory storage requirements for a given resolved scale separation. Basic ...
The history of applying MHD to hypersonic flow simulation in wind tunnels is examined. Advances in MHD technology derived from generator technology are discussed. The design requirements for using MHD accelerators and generators in a hypersonic wind tunnel are described.
The present report on preliminary results of theoretical and experimental investigations of power flow in a large, unoptimized, multimegawatt coaxial thruster evaluates the significance of these data for the development of efficient, megawatt-class magnetoplasmadynamic (MPD) thrusters. The good agreement obtained between thruster operational performance and model predictions ...
Landau's model is used to explain the effect of small fluctuations on MHD flows. The probability density is calculated from the Fokker-Planck equation.
This report examines some of the detailed structure of magnetogasdynamic flows encountered in pulsed magnetohydrodynamic (MHD) generators. Two illustrations of magnetogasdynamic nonuniformities are considered. The first is for conventional explosive-drive...
... 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBERS MHD FLOW CONTROL AND POWER GENERATION IN LOW- FA9550-05-C-0121 ...
Page 1. ISTC 2196P Final Project Technical Report of ISTC 2196p MHD Flow Control (From June 1, 2002 to May 31, 2006) Valentin A. Bltyurln ...
... Accession Number : ADA473536. Title : MHD Flow Control. Descriptive Note : Final rept. 1 Jun 2002-31 May 2006. Corporate ...
... Title : INTERNAL MHD CHANNEL FLOWS INCLUDING HALL EFFECT AND VARIABLE FLUID PROPERTIES. Descriptive Note : Final rept.,. ...
Many astrophysical processes involving magnetic fields and quasi-stationary processes are well described when assuming the fluid as a perfect conductor. For these systems, the ideal-magnetohydrodynamics (MHD) description captures the dynamics effectively and a number of well-tested techniques exist for its numerical solution. Yet, there are several ...
In the framework of the variational principle the canonical variables describing magnetohydrodynamic (MHD) flows of general type (i.e., with spatially varying entropy and nonzero values of all topological invariants) are introduced. It is shown that the velocity representation of the Clebsch type following from the variational principle with constraints is ...
The time-dependent, 2[1/2]-dimensional, axisymmetric, magnetohydrodynamics (MHD) solver, MACH2 has been upgraded to include the effects of nonequilibrium air chemistry in order to properly model weakly ionized flows over high-speed vehicles. The thermochemical model was subjected to several validation cases such as comparisons to the experimentally deduced ...
A numerical method for the stability analysis of ideal MHD modes is devised by using a physical model based on the two-dimensional Newcomb equation in combination with the conventional ideal MHD model. The MARG2D code based on this numerical method is able to analyze the stability of ideal ...
... effect on the hypersonic turbulent flow field was ... Parameter for MHD Flows with Transverse ... for an electrically conducting incompressible medium in ...
... features and characteristics of Hartmann flows in the Faraday generator configuration are reported ... of slip between gas-liquid phases in the flow. ...
Magnetic fields play an important role in astrophysics on a wide variety of scales, ranging from the Sun and compact objects to galaxies and galaxy clusters. Here we discuss a novel implementation of ideal magnetohydrodynamics (MHD) in the moving-mesh code AREPO which combines many of the advantages of Eulerian and Lagrangian methods in a single ...
ULYSSES spacecraft solar polar passes at solar minimum provide in-situ observations of evolving MHD turbulence in the solar wind under ideal conditions of fast quiet flow. The recent unusually inactive solar minimum shows a decrease in the turbulent fluctuations of a factor of two in power in comparison with the previous minimum. We ...
Magnetohydrodynamics is a fluid model for the motion of an ionized gas in a magnetic field. In its ideal, non-dissipative form, the Lundquist equations, it has the same mathematical character as the model for gas dynamics. It gives, in the same way, a self-consistent description of the fluid dynamics, including the exchange of momentum and energy between the field and the ...
The ideal MHD linear stability normal modes and frequencies for a circular cylindrical plasma (having an arbitrary equilibrium flow) interacting with a resistive wall are calculated. Projections of the plasma displacement are expanded as finite elements, using a Galerkin approach to form the inner products. A Green's function approach ...
A systematic study of the linear stage of sheared flow stabilization of Z-pinch plasmas based on the Hall fluid model with equilibrium that contains sheared flow and an axial magnetic field is presented. In the study we begin with the derivation of a general set of equations that permits the evaluation of the combined effect of sheared ...
Dynamic models of the coronal magnetic field show promise as space weather forecasting tools. Such models should be driven by electric fields derived from sequences of photospheric vector magnetograms, the only routine measurements of the solar magnetic field currently available. Previous studies derived flows --- or, equivalently, ideal electric fields ...
A novel approach to the physical modeling and computational simulation of two-dimensional, electrically, magnetically, and thermally driven incompressible magnetofluid is described. The flow dynamics is governed by the incompressible MHD equations coupled to external electric and magnetic fields, buoyancy forces, and convective or conductive heat transfer. ...
The 3-D supersonic viscous flow in an experimental MHD channel has been numerically simulated. The experimental MHD channel is currently in operation at NASA Ames Research Center. The channel contains a nozzle section, a center section, and an accelerator...
The potentialities of MHD effect for flow control in a scramjet inlet are discussed. In the papers it is shown that the MHD interaction allows one to control the oblique shocks position and to make the flow field in the inlet at off-design conditions quit...
As part of the MHD program, DOE is sponsoring efforts to define the design criteria and performance requirements for components downstream of the diffuser in an MHD gas flow train. The objectives of this study are to assess the effects of coal cleaning an...
A three-dimensional model incorporating fully the interaction between the flow and electrical fields in MHD channels is presented. The model consists of Navier-Stokes equations in parabolic form, Maxwell and Ohm's equations as they apply to the MHD situat...
A milestone and status report is presented for the MHD coal-fired flow facility. A chart outlining the accrued project cost is also given.
This report contains the operations schedule for the month of May 1995 at the University of Tennessee Space Institute`s Coal Fired MHD Flow Facility.
This report contains the operations schedule for the month of June 1995 at the University of Tennessee Space Institute`s Coal Fired MHD Flow Facility.
The report consists of the following two parts: Shock tube flow passing through a section of a linear MHD generator; and Establishment of quasi-steady conditions in a blow-down non-equilibrium MHD generator.
The tearing mode is an important resistive magnetohydrodynamic (MHD) mode. The magnetic island structure which it nonlinearly produces can degrade the plasma confinement and reduce fusion reactions. This thesis studies several tearing mode problems from both theoretical and experimental points of view. A major part of this thesis is to demonstrate that Electron Cyclotron ...
