Confinement and re-expansion of laser induced plasma in transverse magnetic field: Dynamical behaviour and geometrical aspect of expanding plume

2015 ◽  
Vol 379 (37) ◽  
pp. 2215-2220 ◽  
Author(s):  
Narayan Behera ◽  
R.K. Singh ◽  
Ajai Kumar
Keyword(s):  
Magnetic Field ◽  
Transverse Magnetic Field ◽  
Transverse Magnetic ◽  
Dynamical Behaviour ◽  
Geometrical Aspect ◽  
Laser Induced Plasma

Investigation of the Capabilities of Transverse Magnetic Field Controlled Laser-Induced Plasma Micro-Machining

2020 ◽  
Vol 143 (6) ◽  
Author(s):  
Yanming Zhang ◽  
Yayun Liu ◽  
Suman Bhandari ◽  
Guojun Zhang ◽  
Jianxin Deng ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Surface Quality ◽  
Transverse Magnetic Field ◽  
Transverse Magnetic ◽  
Magnetic Field Direction ◽  
Micro Machining ◽  
Laser Induced Plasma ◽  
Aspect Ratios ◽  
Machining Characteristics

Abstract Laser-induced plasma micro-machining (LIPMM) has proven a number of advantages in micro-machining due to reduced thermal defects, smaller heat-affected zones, and larger aspect ratios when compared with conventional laser ablation. The present work explores the use of external magnetic fields to further enhance process outcomes in LIPMM. Specifically, machining characteristics and outcomes including plasma intensity, attainable aspect ratios, and surface quality will be explored through a theoretical and experimental study in different classes of materials in a transverse magnetic field controlled LIPMM. First, process improvement mechanisms are illustrated in terms of plasma confinement and laser absorption in transverse magnetic fields. A magnetic field redistribution analysis is performed to reveal the differences in the achievable enhancements in machining characteristics in terms of material characteristics. Second, a set of single-factor experiments is conducted to investigate the effects of the strength and direction of the magnetic field on machining capabilities in magnetic and nonmagnetic materials (410, 304 stainless steels and silicon). The experimental results show that plasma intensity and aspect ratios can be significantly increased in the presence of transverse magnetic fields. The greatest influence on machining capability is achieved in a magnetic material. In this case, plasma intensity and aspect ratios were increased by about 176% and 160%, respectively, when compared with other materials with a magnetic field strength of 0.1 T and a magnetic field direction parallel to the processing direction. Finally, the morphology and cross-section profiles of micro-channels have been measured for verifying the impact on the surface quality of transverse magnetically controlled LIPMM.

Numerical study of the effect of transverse magnetic field on cylindrical and hemispherical CZ crystal growth of silicon

2010 ◽  
Vol 46 (4) ◽  
pp. 393-402 ◽  
Author(s):  
F. Mokhtari ◽  
A. Bouabdallah ◽  
A. Merah ◽  
S. Hanchi ◽  
A. Alemany
Keyword(s):  
Magnetic Field ◽  
Crystal Growth ◽  
Transverse Magnetic Field ◽  
Numerical Study ◽  
Transverse Magnetic

Heat Transfer in Liquid Metal at an Upward Flow in a Pipe in Transverse Magnetic Field

2020 ◽  
Vol 58 (3) ◽  
pp. 400-409
Author(s):  
N. A. Luchinkin ◽  
N. G. Razuvanov ◽  
I. A. Belyaev ◽  
V. G. Sviridov
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Liquid Metal ◽  
Transverse Magnetic Field ◽  
Transverse Magnetic ◽  
Upward Flow

scholarly journals Decay of turbulence in a liquid metal duct flow with transverse magnetic field

2019 ◽  
Vol 867 ◽  
pp. 661-690 ◽  
Author(s):  
Oleg Zikanov ◽  
Dmitry Krasnov ◽  
Thomas Boeck ◽  
Semion Sukoriansky
Keyword(s):  
Magnetic Field ◽  
Transverse Magnetic Field ◽  
Large Scale ◽  
High Amplitude ◽  
Transverse Magnetic ◽  
Duct Flow ◽  
Velocity Fluctuations ◽  
Turbulence Decay ◽  
The Moment ◽  
Typical Length

Decay of honeycomb-generated turbulence in a duct with a static transverse magnetic field is studied via direct numerical simulations. The simulations follow the revealing experimental study of Sukoriansky et al. (Exp. Fluids, vol. 4 (1), 1986, pp. 11–16), in particular the paradoxical observation of high-amplitude velocity fluctuations, which exist in the downstream portion of the flow when the strong transverse magnetic field is imposed in the entire duct including the honeycomb exit, but not in other configurations. It is shown that the fluctuations are caused by the large-scale quasi-two-dimensional structures forming in the flow at the initial stages of the decay and surviving the magnetic suppression. Statistical turbulence properties, such as the energy decay curves, two-point correlations and typical length scales are computed. The study demonstrates that turbulence decay in the presence of a magnetic field is a complex phenomenon critically depending on the state of the flow at the moment the field is introduced.

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