scholarly journals Experimental Investigations on the Effect of Axial Homogenous Magnetic Fields on Propagating Vortex Flow in the Taylor–Couette System

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4027
Author(s):  
Thomas Ilzig ◽  
Katharina Stöckel ◽  
Stefan Odenbach
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Vortex Flow ◽  
Axial Magnetic Field ◽  
Intermittent Flow ◽  
Experimental Investigations ◽  
Temporal Behavior ◽  
Flow State ◽  
Orbital Frequency ◽  
Taylor Couette

Experimental investigations of propagating vortex flow states (pV states) in a short Taylor–Couette system with asymmetric boundary conditions are presented. The flow state was established in a ferrofluid showing no magneto-viscous effect and was exposed to axial magnetic fields. It was found that the magnetic field led to a change in the spatial and temporal behavior of the pV state, indicating complex interactions between the flow field and magnetic field. A stepwise applied axial magnetic field destabilized the pV state, leading to an intermittent flow state. Gradually increasing the axial magnetic fields changed the temporal behavior of the regime. Up to magnetic field strengths of 20 kA/m, the orbital frequency, as a measure for the temporal periodicity, was increased with field strength.

Hydromagnetic Taylor–Couette flow: wavy modes

2002 ◽  
Vol 472 ◽  
pp. 399-410 ◽  
Author(s):  
A. P. WILLIS ◽  
C. F. BARENGHI
Keyword(s):  
Magnetic Field ◽  
Couette Flow ◽  
Vortex Flow ◽  
Axial Magnetic Field ◽  
Taylor Vortex ◽  
Taylor Vortex Flow ◽  
Critical Reynolds Numbers ◽  
Taylor Couette ◽  
Axisymmetric Solutions ◽  
Taylor Couette Flow

We investigate magnetic Taylor–Couette flow in the presence of an imposed axial magnetic field. First we calculate nonlinear steady axisymmetric solutions and determine how their strength depends on the applied magnetic field. Then we perturb these solutions to find the critical Reynolds numbers for the appearance of wavy modes, and the related wave speeds, at increasing magnetic field strength. We find that values of imposed magnetic field which alter only slightly the transition from circular-Couette flow to Taylor-vortex flow, can shift the transition from Taylor-vortex flow to wavy modes by a substantial amount. The results are compared to those for onset in the absence of a magnetic field.

Turbulence changes from magnetic fields in a stationary plasma

2010 ◽  
Vol 77 (4) ◽  
pp. 537-545 ◽  
Author(s):  
A. B. ALEXANDER ◽  
C. T. RAYNOR ◽  
D. L. WIGGINS ◽  
M. K. ROBINSON ◽  
C. C. AKPOVO ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Axial Magnetic Field ◽  
Turbulent Energy ◽  
Dominant Mode ◽  
Dc Glow Discharge ◽  
Turbulent Fluctuations ◽  
Stationary Plasma

AbstractWhen the krypton plasma in a DC glow discharge tube is exposed to an axial magnetic field, the turbulent energy and the characteristic dominant mode in the turbulent fluctuations are systematically and unexpectedly reduced with increasing magnetic field strength. When the index measuring the rate of transfer of energy through fluctuation scales is monitored, a lambda-like dependence on turbulent energy is routinely observed in all magnetic fields. From this, a critical turbulent energy is identified, which also decreases with increasing magnetic field strength.

Macro and Microstructural Effects of the Application of an Induced Axial Magnetic Field During the Deposition of Aluminum Weld Beads

2009 ◽  
Vol 1242 ◽  
Author(s):  
M. A. García ◽  
V. H. López M. ◽  
R. García H. ◽  
F. F. Curiel L. ◽  
R. R. Ambríz R.
Keyword(s):  
Magnetic Field ◽  
Grain Size ◽  
Magnetic Fields ◽  
Weld Metal ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Axial Magnetic Field ◽  
Grain Structure ◽  
Bead Geometry ◽  
External Power Source

ABSTRACTIn this work, aluminum weld beads were deposited on aluminum plates of commercial purity (12.7 mm thick), using an ER-5356 filler wire. The aim of the experiments was to assess the effects that yield the induction of an axial magnetic field (AMF) during the application of the weld beads using the direct current gas metal arc welding process (DC-GMAW). An external power source was use to induce magnetic fields between 0 to 28 mT. The effects of the magnetic fields were assessed in terms of the macrostructural features of the deposits, morphology of the grain structure, grain size and grain size distribution in the weld metal. Macrostructural characteristics of the weld beads revealed that increasing the intensity of the magnetic induction to produce a magnetic field above 14 mT, leads to a significant loss of feeding material and there is a tendency of the deposits to increase their width and reduce penetration. Perturbation of the weld pool induced by the application of the AMF noticeably modified the grain structure in the weld metal. In particular, for the intensities of 5 and 14 mT, columnar growth was essentially non-existent. Grain size distribution plots showed, generally speaking, that the use of magnetic fields is an efficient method to produce homogeneous grain structures within the weld metal. Finite element analysis was used to explain the weld bead geometry with the intensity of the magnetic field.

Axial magnetic field contacts with nonuniform distributed axial magnetic fields

2003 ◽  
Vol 31 (2) ◽  
pp. 289-294 ◽  
Author(s):  
Zongqian Shi ◽  
Shenli Jia ◽  
Jun Fu ◽  
Zheng Wang
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Axial Magnetic Field

scholarly journals Axial Magnetic Field Effect on Taylor-Couette Flow

2015 ◽  
Vol 8 (2) ◽  
pp. 255-264
Author(s):  
Sofiane ABERKANE ◽  
IHDENE malika ◽  
mouderes mourad ◽  
A. Ghezal ◽  
◽  
...  
Keyword(s):  
Magnetic Field ◽  
Couette Flow ◽  
Field Effect ◽  
Axial Magnetic Field ◽  
Magnetic Field Effect ◽  
Taylor Couette ◽  
Taylor Couette Flow

Experimental Investigations of the Surface Groove Effect in Taylor-Couette-Poiseuille Flow

2020 ◽  
Author(s):  
Lamia Gaied ◽  
Fethi Aloui ◽  
Marc Lippert ◽  
Emna Berrich
Keyword(s):  
Couette Flow ◽  
Vortex Flow ◽  
Axial Flow ◽  
Vortex Structures ◽  
Base Flow ◽  
Taylor Vortex ◽  
Experimental Investigations ◽  
Surface Groove ◽  
Taylor Couette ◽  
The Impact

Abstract In this paper, we investigate the effects of an imposed axial flow on hydrodynamic instabilities’ Couette-Taylor flow in the case where the wall of the inner cylinder of the system is grouved. Without imposed axial flow, the basic flow of a fluid between two coaxial cylinders known by Couette flow, which is characterized by several temporal and spatial symmetries. The increase in the rotation causes the breaking of these symmetries. In both cases where the surface of the inner cylinder is smooth and grooved, five different flow regimes can be determined: Taylor vortex flow (TVF), wavy vortex flow (WVF), and Modulated Wavy vortex flow (MWVF). Each time the flow passes from one hydrodynamic regime to another until it enters a state of turbulence, which is characterized by the destruction of all the symmetries that existed at the beginning. In addition, when an axial flow is imposed on a Taylor-Couette flow, new helical vortex structures are observed in both cases (with and without surface groove). The influence of surface structures (grooves) on the shear stress of the wall is discussed with and without axial base flow. A spatio-temporal description of several flow models was obtained using firstly, a visualization’s qualitative study using kalliroscope particles. Secondly, a quantitative study by polarography using simple probes have been used to characterize the impact of vortex structures on the Couette-Taylor flows without and with an axial flow on the transfer.

Improvement of UNS S32205 Duplex Welds by GMAW and Controlled Magnetic Field for Offshore Pipelines and Flowlines Applications

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
M. Salazar ◽  
R. García ◽  
V. H. López ◽  
R. Galván-Martínez ◽  
A. Contreras
Keyword(s):  
Magnetic Field ◽  
Corrosion Resistance ◽  
Magnetic Fields ◽  
Impact Toughness ◽  
Axial Magnetic Field ◽  
Gas Metal Arc Welding ◽  
Tensile Tests ◽  
Offshore Pipelines ◽  
Metal Arc Welding ◽  
Different Temperatures

Mechanical properties and corrosion resistance of UNS S32205 duplex stainless steel (DSS) welds obtained under the application of controlled magnetic fields were evaluated in the context of offshore pipelines and flowlines applications. Tensile tests, impact toughness, and hardness measurements were performed. Corrosion behavior was evaluated by linear polarization resistance (LPR) and potentiodynamic polarization curves (PCs) using a synthetic seawater solution at different temperatures. An improvement in tensile strength, impact toughness, and corrosion resistance was observed with the application of magnetic fields during welding. This effect is attributed to the refinement in the microstructure of the weld metal along with the suppression of detrimental intermetallic tertiary phases. Applying an axial magnetic field of 3 mT during DSS welding by the gas metal arc welding (GMAW) process is a potential technique for improving the performance of offshore pipeline welds and may be implemented in both, double-sided single pass and single-sided multipass butt joints.

1103 Magnetic field control of mode bifurcation on magnetic fluid Taylor-Couette vortex flow with small aspect ratio

2005 ◽  
Vol 2005 (0) ◽  
pp. 159
Author(s):  
Daisuke ITO ◽  
Toshikazu KOTAKA ◽  
Hiroshige KIKURA ◽  
Masanori ARITOMI ◽  
Yasushi TAKEDA
Keyword(s):  
Magnetic Field ◽  
Aspect Ratio ◽  
Magnetic Fluid ◽  
Vortex Flow ◽  
Small Aspect Ratio ◽  
Field Control ◽  
Taylor Couette

scholarly journals Gas–puff Z pinches with strong axial magnetic fields

1987 ◽  
Vol 5 (4) ◽  
pp. 699-706 ◽  
Author(s):  
F. S. Felber ◽  
F. J. Wessel ◽  
N. C. Wild ◽  
H. U. Rahman ◽  
A. Fisher ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Inertial Confinement Fusion ◽  
Scaling Laws ◽  
Axial Magnetic Field ◽  
Argon Laser ◽  
Nitrogen Laser ◽  
Inertial Confinement ◽  
X Ray ◽  
Confinement Fusion

Ultrahigh axial magnetic fields have been compressed and measured in a gas-puff Z pinch. A 0·5-MA, 2–cm-radius annular gas-puff Z pinch with a 3-minute repetition rate was imploded radially onto an axial seed field, causing the field to compress. Axial magnetic field compressions up to 180 and peak magnetic fields up to 1·6 MG were measured. Faraday rotation of an argon laser (515·4 nm) in a quartz fiber on axis was the principal magnetic field diagnostic. Other diagnostics included a nitrogen laser interferometer, x-ray diodes, and magnetic field probes.The magnetic field compression results are consistent with simple snowplow and self-similar analytic models, which are presented. The axial magnetic fields strongly affect the Z pinch dynamics. Even small axial fields help stabilize the pinches, some of which exhibit several stable radial bounces during a current pulse.The method of compressing axial fields in a gas-puff Z pinch is extrapolable to the order of 100 MG. Scaling laws are presented. Potential applications of ultrahigh axial fields in Z pinches are discussed for x-ray lasers, inertial confinement fusion, and collimated sources of gamma radiation.

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