The Ablation Mechanism of Magnetic Driven Flyer Plate

2014 ◽  
Vol 574 ◽  
pp. 416-420
Author(s):  
Gang Hua Wang ◽  
Ming Xian Kan ◽  
Yi Fei Niu ◽  
Hai Long Zhao
Keyword(s):  
Free Surface ◽  
Stress Wave ◽  
Thermal Conduction ◽  
High Speed ◽  
Ohmic Heating ◽  
Surface Velocity ◽  
Free Surface Velocity ◽  
Magnetic Diffusion ◽  
Ablation Mechanism ◽  
Velocity History

It is found that the samples usually melt and even gasify in the magnetic driven high-speed flying plate experiments, which phenomenon goes against the investigation on materials’ equation of state (EOS). To understand this phenomenon, the whole process of magnetic driven flying plate experiment is simulated by the magnetohydrodynamic code MDSC. The ablation mechanism of magnetic driven flying plate is analyzed through the control of thermal conduction coefficient, and resistivity coefficient which is related to the magnetic diffusion velocity, in the energy conversing equation. Inside the flying plate the velocity of stress wave is much higher than that of magnetic diffusion, and hence the current goes into the inside of sample no early than the stress wave, so the magnetic diffusion doesn’t play an important role in the first stage of flyer free surface velocity history. The thermal conduction doesn’t influence the whole free surface velocity history of the flying plate much, while the Ohmic heating has a big effect on it, without which more than 20% error will be produced. The energy transportation in the flying plate medium is mainly caused by the Ohmic heating from magnetic diffusion. Besides, the relationship between the magnetic diffusion and temperature of flying plate is also analyzed.

scholarly journals Experimental Study on Geysers Induced by the Release of Trapped Air in Storage Tunnel Systems

2019 ◽  
Vol 9 (24) ◽  
pp. 5326
Author(s):  
Xiaosheng Wang ◽  
Shangtuo Qian ◽  
Hongxun Chen
Keyword(s):  
Experimental Study ◽  
Free Surface ◽  
High Speed ◽  
Gas Flow ◽  
Critical Infrastructure ◽  
External Pressure ◽  
Surface Velocity ◽  
Free Surface Velocity ◽  
Trapped Air ◽  
Tunnel System

A storage tunnel system is the critical infrastructure of urban drainage systems, in which the rapid filling of water and release of trapped air can lead to the “geyser” phenomenon. This may cause serious damage, threatening both system operation and personal safety. In this paper, a detailed experimental study was carried out based on synchronous recorded video images and digital image processing technology. According to experimental observations, gas-flow geysers and surge-type geysers were analyzed deeply. The former is caused by high-speed gas flow and is accompanied by a pressure drop; the latter is caused by surge pressure and is accompanied by a pressure increase. The free surface velocity of the gas-flow geyser is mainly affected by the external pressure, the air volume, the diameter of the shaft, and the height of the water column, and the geyser phenomenon cannot occur when the air column is mainly dominated by buoyancy. Based on dimensional analysis and data fitting, this paper presents the empirical formula for the free surface velocity and the interface net velocity and puts forward the critical occurrence conditions for the gas-flow geyser.

scholarly journals Identification of Ellis rheological law from free surface velocity

2019 ◽  
Vol 263 ◽  
pp. 15-23 ◽  
Author(s):  
Abdulrahman Al-Behadili ◽  
Mathieu Sellier ◽  
James N. Hewett ◽  
Roger I. Nokes ◽  
Miguel Moyers-Gonzalez
Keyword(s):  
Free Surface ◽  
Surface Velocity ◽  
Free Surface Velocity

Evaluation of Marangoni convection and free surface velocity of molten tungsten for tungsten divertor

2019 ◽  
Vol 140 ◽  
pp. 117-122 ◽  
Author(s):  
Kohei Hamaguchi ◽  
Eiji Hoashi ◽  
Takafumi Okita ◽  
Kenzo Ibano ◽  
Yoshio Ueda
Keyword(s):  
Free Surface ◽  
Marangoni Convection ◽  
Surface Velocity ◽  
Free Surface Velocity

scholarly journals Discussion on the physical meaning of free surface velocity curve in ductile spallation

2015 ◽  
Vol 64 (3) ◽  
pp. 034601
Author(s):  
Pei Xiao-Yang ◽  
Peng Hui ◽  
He Hong-Liang ◽  
Li Ping
Keyword(s):  
Free Surface ◽  
Physical Meaning ◽  
Velocity Curve ◽  
Surface Velocity ◽  
Free Surface Velocity

Free Surface, Velocity Gradient Flow Past Hemisphere

1970 ◽  
Vol 96 (7) ◽  
pp. 1485-1502
Author(s):  
Gordon H. Flammer ◽  
J. Paul Tullis ◽  
Earl S. Mason
Keyword(s):  
Free Surface ◽  
Velocity Gradient ◽  
Gradient Flow ◽  
Surface Velocity ◽  
Free Surface Velocity ◽  
Flow Past

Jet Impingement of a Non-Newtonian Fluid

2006 ◽  
Author(s):  
Jiangang Zhao ◽  
Roger E. Khayat
Keyword(s):  
Boundary Layer ◽  
Free Surface ◽  
Hydraulic Jump ◽  
Similarity Solutions ◽  
Surface Velocity ◽  
Free Surface Velocity ◽  
Viscous Boundary Layer ◽  
Boundary Layer Region ◽  
Layer Region ◽  
Viscous Boundary

The similarity solutions are presented for the wall flow which is formed when a smooth planar jet of power-law fluids impinges vertically on to a horizontal plate, and spreads out in a thin layer bounded by a hydraulic jump. This problem is formulated analogous to radial jet flow problem and the solution procedure is accounted for by means of similarity solution of the boundary-layer equation [1] for Newtonian fluids. For the convenience of analysis, the flow may be divided into three regions, namely a developing boundary-layer region, a fully viscous boundary-layer region, and a hydraulic jump region. The similarity solutions of the film thickness and free surface velocity in fully viscous boundary-layer region include unknown constant L, which is solved numerically and approximately in the developing boundary-layer flow region. Comparison between the numerical and approximate solutions leads generally to good agreement, except for severely shear-thinning fluids. The boundary-layer solution depends on two parameters: power-law index n and α, the dimensionless flow parameters. The effect of α on film thickness and free surface velocity is investigated. The relations between the position of the hydraulic jump and dimensionless flow parameter are obtained and the effect of α on the position of the jump is presented.

Messung des Chapman-Jouguet-Druckes mit Röntgen-Absorption

1981 ◽  
Vol 36 (5) ◽  
pp. 437-442
Author(s):  
K. Hollenberg ◽  
H.-R. Kleinhanß ◽  
G. Reiling
Keyword(s):  
Free Surface ◽  
Pressure Range ◽  
Detonation Front ◽  
Surface Velocity ◽  
Free Surface Velocity ◽  
High Explosives ◽  
X Ray ◽  
X Ray Absorption

Abstract The Chapman Jouguet pressure of some high explosives is measured by X-ray absorption giving the density behind the detonation front. An accuracy of 2 - 3% was achieved in the pressure range of 200 kbar. The pressures are considerably lower than comparable results of other authors obtained by the free surface velocity method or similar techniques.

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