scholarly journals Numerical Simulation on Saffman Force Controlled Inclusions Removal during the ESR Process

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 647 ◽  
Author(s):  
Chuxiong Sun ◽  
Yifeng Guo ◽  
Qiang Li ◽  
Zhe Shen ◽  
Tianxiang Zheng ◽  
...  
Keyword(s):  
Metal Film ◽  
Molten Slag ◽  
Nonmetallic Inclusions ◽  
Main Stage ◽  
Two Dimensional ◽  
Inclusion Removal ◽  
Buoyant Force ◽  
Center Position ◽  
Large Velocity ◽  
Large Velocity Gradient

Electroslag remelting (ESR) is an effective method for removing nonmetallic inclusions from steels or alloys. The main stage of inclusion removal during ESR is the aggregation of liquid metal film (LMF) to form droplets at the consumable electrode tip. In this study, a lab-level ESR experiment was carried out. The number and size of inclusions at the characteristic position of the electrode were quantitatively counted. The number of inclusions in the center position of LMF were larger than that in other regions. To elucidate these phenomena, a two-dimensional mathematical model was established to study the migration of inclusions in LMF. The results indicate that due to the large velocity gradient in LMF, the Saffman force is strong enough to offset the buoyant force and drag the inclusions toward the slag/LMF interface (SFI), where the inclusions will be dissolved in the SFI region by the molten slag. This study demonstrates that the Saffman force plays a key role in the removal of nonmetallic inclusions in LMF during the ESR process.

scholarly journals 1.7” Resolution CO(1-0) Observations of ARP220: Nuclear Gas Ring of Merger Remnant

1994 ◽  
Vol 140 ◽  
pp. 376-378 ◽  
Author(s):  
S. K. Okumura ◽  
R. Kawabe ◽  
M. Ishiguro ◽  
S. Ishizuki
Keyword(s):  
Central Region ◽  
Emission Peak ◽  
Molecular Gas ◽  
Velocity Range ◽  
No Emission ◽  
Large Velocity ◽  
Nuclear Ring ◽  
Compact Sources ◽  
Large Velocity Gradient ◽  
Co Emission

AbstractWe made aperture synthesis CO(l-O) observations of the central region of Arp220 with the Nobeyama Millimeter Array. Central CO emission was resolved with a size of 975 kpc. It shows a ring-like structure (ɪ ~ 500 pc) with a large velocity gradient, 393 km · s−1 · kpc−1, from southwest to northeast direction. The ring-like emission is located around double radio compact sources. No emission peak was found in the center of the double sources within the velocity range 5100 km s−1to 5800 km s−1. These results suggest that an inclined massive gas ring has been or is being formed in the central 1 kpc of Arp220. Most of the molecular gas in Arp220 is concentrated on this nuclear ring. The radio compact sources are probably located at the inner egde of the ring.

FDTD Numerical Analysis of Transmission Enhancement on Two-Dimensional Hole Array

2012 ◽  
Vol 182-183 ◽  
pp. 929-932
Author(s):  
Jie Yin ◽  
Shu Yang ◽  
Chong Pan
Keyword(s):  
Metal Film ◽  
Silver Film ◽  
Transmission Rate ◽  
Metal Plate ◽  
Transmission Peak ◽  
Hole Array ◽  
Two Dimensional ◽  
Rate Transmission ◽  
Relative Transmission ◽  
Transmission Enhancement

Numerical simulation about transmission enhancement phenomenon on metal film hole array has been finished in the paper by East FDTD commercial software. In some wavelengths, relative transmission rate is more than 1 and we also study that the thickness of metal plate, the size of the hole and period on influence of the transmission rate. Transmission enhancement peak lowers with the increasing of silver film thickness, enlarger along with the increasing of the aperture, And when period of hole gets larger, transmission peak will shift.

Evidence for two-dimensional phonons in a thin metal film

1991 ◽  
Vol 44 (16) ◽  
pp. 8990-8996 ◽  
Author(s):  
J. C. Nabity ◽  
M. N. Wybourne
Keyword(s):  
Metal Film ◽  
Thin Metal Film ◽  
Thin Metal ◽  
Two Dimensional

scholarly journals The granular buoyant force in a two-dimensional intruder-particles bed system

2019 ◽  
Author(s):  
Dewi Muliyati ◽  
Nurhayati ◽  
Johri Sabaryati ◽  
Sparisoma Viridi
Keyword(s):  
Two Dimensional ◽  
Buoyant Force

Nano-Gaps Fabricated by Thermal Evaporation and Stripping Techniques

2021 ◽  
Vol 21 (9) ◽  
pp. 4852-4856
Author(s):  
E Cheng ◽  
Suzhou Tang ◽  
Helin Zou ◽  
Guochao Qiao ◽  
Zhengyan Zhang
Keyword(s):  
Silicon Substrate ◽  
Metal Film ◽  
Thermal Evaporation ◽  
Low Cost ◽  
Adhesive Force ◽  
Metal Films ◽  
Two Dimensional ◽  
Structural Morphology ◽  
Simple Method

The fabrication of inexpensive nano-gaps is vitally important for the research and application of nanochannel-based devices. This study presents a low-cost and simple method for the fabrication of nano-gaps using thermal evaporation and stripping techniques. The structural morphology of metal films deposited on the convex structures of photoresist by sputtering and thermal evaporation was studied. The effect of angles of thermal evaporation on the width of nano-gaps was investigated. The characteristics of metal film deposited on the convex structures of photoresist and spaces between these convex structures after stripping were investigated, and the adhesive force between the metal film and silicon substrate was also analyzed. Finally, a metal film of Cu was deposited on the convex structures of photoresist by thermal evaporation. After stripping, nano-gaps with a width of 187 nm were fabricated. The method proposed in this paper can be employed to mass-produce two-dimensional nanochannels based devices at low cost.

scholarly journals Effect of variation in density on the stability of superposed streams of Fluid

1931 ◽  
Vol 132 (820) ◽  
pp. 499-523 ◽  
Keyword(s):  
Density Gradient ◽  
Velocity Gradient ◽  
Horizontal Plane ◽  
Experimental Results ◽  
Large Velocity ◽  
Formed Part ◽  
The Stability ◽  
Large Velocity Gradient

1. The chief part of the work described in this paper was done in 1914 and formed part of the essay for which the Adams Prize was awarded in 1915. During the war years it was laid aside, and since then I have delayed publica­tion, hoping to be able to undertake experiments designed to verify, or otherwise, the results. Lately, however, Mr. Goldstein has told me that he is engaged on similar problems and he has encouraged me to publish the work without waiting for experimental results. It is well known that when the wind near the ground drops at night owing to the cooling of the ground, the wind at a higher level frequently remains unchanged so that the effect of a decrease in density with height is to enable a large velocity gradient to be maintained. This implies that the turbulence is suppressed or at any rate much reduced by the density gradient. To the mathematician this at once presents the problem of the stability of a fluid in which the density and velocity vary with height above the ground, regarded as a horizontal plane.

scholarly journals Levitation of a drop over a moving surface

2013 ◽  
Vol 733 ◽  
Author(s):  
Henri Lhuissier ◽  
Yoshiyuki Tagawa ◽  
Tuan Tran ◽  
Chao Sun
Keyword(s):  
Film Thickness ◽  
Wall Motion ◽  
Angular Position ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Capillary Length ◽  
Large Velocity ◽  
Rotating Hollow Cylinder ◽  
Drag And Lift ◽  
Air Film

AbstractWe investigate the levitation of a drop gently deposited onto the inner wall of a rotating hollow cylinder. For a sufficiently large velocity of the wall, the drop steadily levitates over a thin air film and reaches a stable angular position in the cylinder, where the drag and lift balance the weight of the drop. Interferometric measurements yield the three-dimensional (3D) air film thickness under the drop and reveal the asymmetry of the profile along the direction of the wall motion. A two-dimensional (2D) model is presented which explains the levitation mechanism, captures the main characteristics of the air film shape and predicts two asymptotic regimes for the film thickness ${h}_{0} $: for large drops ${h}_{0} \sim {\mathit{Ca}}^{2/ 3} { \kappa }_{b}^{- 1} $, as in the Bretherton problem, where $\mathit{Ca}$ is the capillary number based on the air viscosity and ${\kappa }_{b} $ is the curvature at the bottom of the drop; for small drops ${h}_{0} \sim {\mathit{Ca}}^{4/ 5} {(a{\kappa }_{b} )}^{4/ 5} { \kappa }_{b}^{- 1} $, where $a$ is the capillary length.

On the motion of particles in a fluid under the influence of a large velocity gradient

1993 ◽  
Vol 14 (1-2) ◽  
pp. 42-48 ◽  
Author(s):  
P. J. Thomas ◽  
K. -A. Bütefisch ◽  
K. H. Sauerland
Keyword(s):  
Velocity Gradient ◽  
Large Velocity ◽  
Large Velocity Gradient
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