Numerical simulation of electrically conducting jet flow in a straight duct under longitudinal homogeneous magnetic field

2019 ◽  
Vol 31 (1) ◽  
pp. 014108 ◽  
Author(s):  
D. Krasnov ◽  
Y. Kolesnikov ◽  
T. Boeck
Keyword(s):  
Magnetic Field ◽  
Numerical Simulation ◽  
Homogeneous Magnetic Field ◽  
Jet Flow ◽  
Electrically Conducting ◽  
Straight Duct

Characterization of the flow past a truncated square cylinder in a duct under a spanwise magnetic field

2011 ◽  
Vol 691 ◽  
pp. 341-367 ◽  
Author(s):  
Vincent Dousset ◽  
Alban Pothérat
Keyword(s):  
Magnetic Field ◽  
Lorentz Force ◽  
Topological Analysis ◽  
Three Dimensional ◽  
Homogeneous Magnetic Field ◽  
Steady Flows ◽  
Square Cylinder ◽  
Electrically Conducting ◽  
Truncated Cylinder ◽  
The Magnetic Field

AbstractWe study the flow of an electrically conducting fluid past a truncated square cylinder in a rectangular duct under the influence of an externally applied homogeneous magnetic field oriented along the cylinder axis. Our aim is to bridge the gap between the non-magnetic regime, where we previously found a complex set of three-dimensional recirculations behind the cylinder (Dousset & Pothérat, J. Fluid Mech., vol. 653, 2010, pp. 519–536) and the asymptotic regime of dominating Lorentz force analysed by Hunt & Ludford (J. Fluid. Mech., vol. 33, 1968, pp. 693–714). The latter regime is characterized by a remarkable structure known as Hunt’s wake in the magnetohydrodynamics community, where the flow is deflected on either side of a stagnant zone, right above the truncated cylinder as if the latter would span the full height of the duct. In steady flows dominated by the Lorentz force, with negligible inertia, we provide the first numerical flow visualization of Hunt’s wake. In regimes of finite inertia, a thorough topological analysis of the steady flow regimes reveals how the Lorentz force gradually reorganizes the flow structures in the hydrodynamic wake of the cylinder as the Hartmann number $\mathit{Ha}$ (which gives a non-dimensional measure of the magnetic field) is increased. The nature of the vortex shedding follows from this rearrangement of the steady structures by the magnetic field. As $\mathit{Ha}$ is increased, we observe that the vortex street changes from a strongly symmetric one to the alternate procession of counter-rotating vortices typical of the non-truncated cylinder wakes.

Control of Flow Separation Around Bluff Obstacles by Transverse Magnetic Field

2012 ◽  
Vol 134 (9) ◽  
Author(s):  
Dipankar Chatterjee ◽  
Kanchan Chatterjee ◽  
Bittagopal Mondal
Keyword(s):  
Magnetic Field ◽  
Numerical Simulation ◽  
Reynolds Number ◽  
Field Strength ◽  
Flow Separation ◽  
Creeping Flow ◽  
Computational Domain ◽  
Number Range ◽  
Electrically Conducting ◽  
Low Reynolds

Electromagnetic fields may be used to control the flow separation during the flow of electrically conducting fluids around bluff obstacles. The steady separated flow around bluff bodies at low Reynolds numbers almost behaves as a creeping flow at a certain field strength. This phenomena, although already known, is exactly quantified through numerical simulation and the critical field strength of an externally applied magnetic field is obtained, for which the flow separation is completely suppressed. The flow of a viscous, incompressible, and electrically conducting fluid (preferably liquid metal or an electrolyte solution) at a Reynolds number range of 10–40 and at a low magnetic Reynolds number is considered in an unbounded medium subjected to uniform magnetic field strength along the transverse direction. Circular and square cross sections of the bluff obstacles are considered for simulation purposes. Fictitious confining boundaries are chosen on the lateral sides of the computational domain that makes the blockage ratio (the ratio of the cylinder size to the width of the domain) 5%. The two-dimensional numerical simulation is performed following a finite volume approach based on the semi-implicit method for pressure linked equations (SIMPLE) algorithm. The major contribution is the determination of the critical Hartmann number for the complete suppression of the flow separation around circular and square cylinders for the steady flow in the low Reynolds number laminar regime. The recirculation length and separation angle are computed to substantiate the findings. Additionally, the drag and skin friction coefficients are computed to show the aerodynamic response of the obstacles under imposed magnetic field conditions.

Laminar-Turbulent Transition in Magnetohydrodynamic Duct, Pipe, and Channel Flows

2014 ◽  
Vol 66 (3) ◽  
Author(s):  
Oleg Zikanov ◽  
Dmitry Krasnov ◽  
Thomas Boeck ◽  
Andre Thess ◽  
Maurice Rossi
Keyword(s):  
Magnetic Field ◽  
Flow Behavior ◽  
Homogeneous Magnetic Field ◽  
Channel Flows ◽  
Conducting Fluid ◽  
Computational Results ◽  
Electrically Conducting ◽  
Turbulent Transition ◽  
Electrically Conducting Fluid ◽  
Laminar Turbulent Transition

A magnetic field imposed on a flow of an electrically conducting fluid can profoundly change flow behavior. We consider this effect for the situation of laminar-turbulent transition in magnetohydrodynamic duct, pipe, and channel flows with homogeneous magnetic field and electrically insulating walls. Experimental and recent computational results obtained for flows in pipes, ducts and channels are reviewed.

scholarly journals MHD Flow of an Incompressible Viscous Fluid through Convergent or Divergent Channels in Presence of a High Magnetic Field

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Reza Hosseini ◽  
Sadegh Poozesh ◽  
Saeed Dinarvand
Keyword(s):  
Magnetic Field ◽  
Viscous Fluid ◽  
Stokes Equations ◽  
Mhd Flow ◽  
Homogeneous Magnetic Field ◽  
Navier Stokes ◽  
Transform Method ◽  
Navier Stokes Equations ◽  
Electrically Conducting ◽  
Non Linear

The flow of an incompressible electrically conducting viscous fluid in convergent or divergent channels under the influence of an externally applied homogeneous magnetic field is studied both analytically and numerically. Navier-Stokes equations of fluid mechanics and Maxwell’s electromagnetism equations are reduced into highly non-linear ordinary differential equation. The resulting non-linear equation has been solved analytically using a very efficient technique, namely, differential transform method (DTM). The DTM solution is compared with the results obtained by a numerical method (shooting method, coupled with fourth-order Runge-Kutta scheme). The plots have revealed the physical characteristics of flow by changing angles of the channel, Hartmann and Reynolds numbers.

Analysis of magneto rheological elastomers for energy harvesting systems

2020 ◽  
Vol 64 (1-4) ◽  
pp. 439-446
Author(s):  
Gildas Diguet ◽  
Gael Sebald ◽  
Masami Nakano ◽  
Mickaël Lallart ◽  
Jean-Yves Cavaillé
Keyword(s):  
Magnetic Field ◽  
Energy Harvesting ◽  
Shear Strain ◽  
Magnetic Induction ◽  
Magnetic Particles ◽  
Homogeneous Magnetic Field ◽  
Electrical Signal ◽  
Harvesting Systems ◽  
Dc Bias ◽  
Magneto Rheological

Magneto Rheological Elastomers (MREs) are composite materials based on an elastomer filled by magnetic particles. Anisotropic MRE can be easily manufactured by curing the material under homogeneous magnetic field which creates column of particles. The magnetic and elastic properties are actually coupled making these MREs suitable for energy conversion. From these remarkable properties, an energy harvesting device is considered through the application of a DC bias magnetic induction on two MREs as a metal piece is applying an AC shear strain on them. Such strain therefore changes the permeabilities of the elastomers, hence generating an AC magnetic induction which can be converted into AC electrical signal with the help of a coil. The device is simulated with a Finite Element Method software to examine the effect of the MRE parameters, the DC bias magnetic induction and applied shear strain (amplitude and frequency) on the resulting electrical signal.

Notizen: Effect of Magnetic Field on Ascorbic Acid Oxidase Activity, I

1986 ◽  
Vol 41 (3) ◽  
pp. 355-358 ◽  
Author(s):  
V. S. Ghole ◽  
P. S. Damle ◽  
W. H.-P. Thiemann
Keyword(s):  
Magnetic Field ◽  
Ascorbic Acid ◽  
Homogeneous Magnetic Field ◽  
Acid Oxidase ◽  
High Substrate Concentration ◽  
Ascorbic Acid Oxidase ◽  
Rate Of Reaction ◽  
Substrate Concentrations ◽  
Burk Plot

A homogeneous magnetic field of 1.1 T strength exhibits a significant influence on the activity of the enzyme ascorbic acid oxidase in vitro. A Lineweaver-Burk plot of the reaction shows the typical pattern of a mixed-type inhibition, i.e. a larger rate of reaction at low substrate concentrations and a smaller rate of reaction at high substrate concentration than that of the control without magnetic field applied.

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