scholarly journals Material impacts and heat flux characterization of an electrothermal plasma source with an applied magnetic field

2017 ◽  
Vol 122 (6) ◽  
pp. 063302 ◽  
Author(s):  
T. E. Gebhart ◽  
R. A. Martinez-Rodriguez ◽  
L. R. Baylor ◽  
J. Rapp ◽  
A. L. Winfrey
Keyword(s):  
Magnetic Field ◽  
Heat Flux ◽  
Applied Magnetic Field ◽  
Plasma Source ◽  
Electrothermal Plasma

scholarly journals Simulation Study on the Motion of Magnetic Particles in Silicone Rubber-Based Magnetorheological Elastomers

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Zhiqiang Xu ◽  
Heng Wu ◽  
Qiuliang Wang ◽  
Liyin Yi ◽  
Jun Wang
Keyword(s):  
Magnetic Field ◽  
Silicone Rubber ◽  
Applied Magnetic Field ◽  
Magnetic Particles ◽  
Equations Of Motion ◽  
Viscous Force ◽  
The Finite Element Method ◽  
Magnetic Field Model ◽  
Magnetorheological Effect

Magnetorheological elastomer (MRE) is an intelligent composite material and has been widely used in various fields such as vibration reduction and sensing. MRE has an excellent magnetorheological effect through the chaining of its internal magnetic particles. Current studies on MREs mainly focus on the preparation of materials and characterization of mechanical properties. However, very few studies have been conducted on the mechanism of magnetic particle motion during MRE curing. Based on the silicone rubber-based MRE, the motion mechanism of magnetic particles during curing was explored through numerical simulation. First, we analyzed the magnetic force and viscous force of magnetic particles in MRE and discussed the equations of motion of magnetic particles under applied magnetic field. Further, we established a uniform magnetic field model through the finite element method and simulated the motion of two magnetic particles under the magnetic field. Finally, we discussed the effects of particle distribution angles, particle radii, applied magnetic field strength, and distance between particles on particle velocity and displacement. The results show that the distance between particles has the greatest influence on the motion of magnetic particles, and the size of the distance between particles will affect the contact time of the particles, thus affecting the chain formation of magnetic particles in the MRE.

scholarly journals Plasma Wind Tunnel Investigation of European Ablators in Nitrogen/Methane Using Emission Spectroscopy

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Ricarda Wernitz ◽  
Christoph Eichhorn ◽  
Thomas Marynowski ◽  
Georg Herdrich
Keyword(s):  
Heat Flux ◽  
Wind Tunnel ◽  
Wavelength Range ◽  
Emission Spectroscopy ◽  
Free Stream ◽  
Plasma Source ◽  
Erosion Product ◽  
Plasma Species ◽  
Dynamic Generator

For atmospheric reentries at high enthalpies ablative heat shield materials are used, such as those for probes entering the atmosphere of Saturn’s moon Titan, such as Cassini-Huygens in December, 2004. The characterization of such materials in a nitrogen/methane atmosphere is of interest. A European ablative material, AQ60, has been investigated in plasma wind tunnel tests at the IRS plasma wind tunnel PWK1 using the magnetoplasma dynamic generator RD5 as plasma source in a nitrogen/methane atmosphere. The dimensions of the samples are 45 mm in length with a diameter of 39 mm. The actual ablator has a thickness of 40 mm. The ablator is mounted on an aluminium substructure. The experiments were conducted at two different heat flux regimes, 1.4 MW/m2 and 0.3 MW/m2. In this paper, results of emission spectroscopy at these plasma conditions in terms of plasma species’ temperatures will be presented, including the investigation of the free-stream species, N2 and N2+, and the major erosion product C2, at a wavelength range around 500 nm–600 nm.

Characterization of the Magnetostriction of Magnetorheological Elastomers

2008 ◽  
Author(s):  
Zelalem Aga ◽  
LeAnn Faidley
Keyword(s):  
Magnetic Field ◽  
Applied Magnetic Field ◽  
Magnetic Particles ◽  
Matrix Material ◽  
Capacitive Sensor ◽  
Solenoid Coil ◽  
Mass Percentage ◽  
Magnetorheological Elastomers ◽  
Filler Particles

Magnetorheological Elastomers (MREs) are polymer composites comprised of an elastomer matrix material with a filler of magnetic particles. The interaction of the filler particles when exposed to a magnetic field can result in a change in stiffness and a strain. However, the main focus of previous research has been on field induced change in stiffness. The goal of this study is therefore to characterize the magnetostriction (field induced strain) of these materials. The measurement of the magnetostriction of MRE was carried out by placing the specimens in a magnetic field produced by a solenoid coil and measuring the resulting strain using a capacitive sensor. A one cycle sinusoidal voltage was input to the solenoid coil that surrounded the MRE specimen to produce the magnetic field. In order to study the effect of mass percentage of iron filler particles on magnetostriction, specimens with different iron filler composition varying from 10 to 30% were produced. The effect of bulk stiffness of the specimen and the magnitude of applied magnetic field on magnetostriction properties has also been studied. The results reveal that increasing the mass percentage of iron in the specimen increases the magnitude of the magnetostriction. In addition, the magnetostriction of MRE showed dependence on the level of applied magnetic field and on the bulk stiffness of the MRE specimens.

scholarly journals Characterization of an electrothermal plasma source for fusion transient simulations

2018 ◽  
Vol 123 (3) ◽  
pp. 033301 ◽  
Author(s):  
T. E. Gebhart ◽  
L. R. Baylor ◽  
J. Rapp ◽  
A. L. Winfrey
Keyword(s):  
Plasma Source ◽  
Electrothermal Plasma ◽  
Transient Simulations
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