Overhead contact line systems for high-speed rails

2018 ◽  
pp. 279-300 ◽  
Author(s):  
Michał Głowacz ◽  
Marek Kaniewski ◽  
Artur Rojek
Keyword(s):  
Contact Line ◽  
High Speed

Wetting contact line modeling in high-speed jet coating

2005 ◽  
Vol 20 (2) ◽  
pp. 217-226 ◽  
Author(s):  
Alfa Arzate ◽  
Philippe A. Tanguy
Keyword(s):  
Contact Line ◽  
High Speed

scholarly journals Thermocapillary rupture of a horizontal liquid layer on a silicon substrate

2019 ◽  
Vol 196 ◽  
pp. 00041
Author(s):  
Dmitry Kochkin ◽  
Valentin Belosludtsev ◽  
Veronica Sulyaeva
Keyword(s):  
Experimental Study ◽  
Contact Line ◽  
High Speed ◽  
Video Camera ◽  
Phase Contact ◽  
High Speed Video ◽  
High Speed Video Camera ◽  
Three Phase ◽  
Breakdown Phenomenon ◽  
Dry Spot

This paper is an experimental study of thermocapillary breakdown phenomenon in a horizontal film of liquid placed on a silicon nonisothermal substrate. With the help of a high-speed video camera the speed of the three-phase contact line was measured during the growth of a dry spot.

Study on the Run-in Process between the Contact Line and Saddle of High-Speed Rail

2013 ◽  
Vol 800 ◽  
pp. 317-320
Author(s):  
Lian Mei Song ◽  
Li Xiao Jia
Keyword(s):  
High Temperature ◽  
Contact Line ◽  
Friction Surface ◽  
High Speed ◽  
Carbon Film ◽  
High Speed Rail ◽  
Slide Surface ◽  
Wear And Friction ◽  
Oxidation Damage ◽  
Theory Calculation

At present the wear and friction of pantograph-contact line is studied widely, while the research of the run-in process is little. In the paper they are obtained that the contact area is 0.96mm2, contact stress is 73MPa, current density is 520A/mm2, the contact resistance is 0.01583 and the contact temperature is 2797K on the surface of slide during the run-in period by the theory calculation. The high temperature of slide surface leads to the oxidation damage. While the carbon film comes into being and the friction surface is tending towards stability.

Detection of Advancing Edge and Existing Length of Precursor Film Ahead Macroscopic Contact Line of Droplet Spreading on Solid Substrate

2008 ◽  
Author(s):  
Ichiro Ueno
Keyword(s):  
Contact Line ◽  
High Speed ◽  
Thin Liquid Film ◽  
Experimental Studies ◽  
Laser Interferometry ◽  
Spreading Rate ◽  
Solid Substrate ◽  
Precursor Film ◽  
Boundary Line ◽  
Droplet Spreading

The author introduces a series of experimental studies on a simple but complex wetting process; a droplet spreads on a solid substrate. The spreading droplet on the solid substrate is accompanied with the movement of a visible boundary line so-called ‘macroscopic contact line.’ Existing studies have indicated there exits a thin liquid film known as ‘precursor film’ ahead the macroscopic contact line of the droplet. The present author’s group has dedicated their special effort to detect the advancing edge of the precursor film by applying a convectional laser interferometry and a high-speed camera, and to evaluate the spreading rate of the precursor film.

PIV and LIF Measurements of Flow in the Vicinity of Moving Interface

2002 ◽  
Author(s):  
Jun Shimizu ◽  
Takahiro Ito ◽  
Yoshiyuki Tsuji ◽  
Yutaka Kukita
Keyword(s):  
Contact Line ◽  
High Speed ◽  
Laser Sheet ◽  
Fluid Velocity ◽  
Argon Laser ◽  
Ccd Camera ◽  
Wall Material ◽  
Video Frame ◽  
Interface Motion ◽  
Stick Slip

The interface between overlaid fluids can become unstable when the fluids are excited vertically. Ito et al. (1999) studied a combined excitation problem where the fluids were excited vertically in a stationary cylinder while the interface motion was restricted by the mobility of the fluid-fluid-wall contact line. They found that the contact line exhibits stick-slip-like motion for the combination of fluids and wall material used in their experiments (water and kerosene oil in a cylinder made of acrylic resin). The flow above and beneath the interface is visualized by adding small particles. A vertical, diametral cross section of the test section is illuminated by a 509-nm Argon laser sheet. The experimental data presented in this paper were taken using ‘EXPANCEL’ particle tracer with a typical diameter of 10 µm, added to the water above and beneath the interface. Pictures are taken by a high-speed CCD camera at a rate of 120 frame/s. Each uninterlaced (120 frame/s) video frame is divided into 640 × 480 pixels for image processing. The fluid velocity is obtained for each 2.95 mm × 2.95 mm area by using the PIV technique. Visualization studies have revealed that the nonuniform velocity distribution above and below the interface extends to a much greater depth than the wave amplitude. Streamlines were taken by using Rhodamine-B fluorescent dye which was added to water beneath the interface and excited with an Ar laser fan beam, with a CCD camera.

High Speed Machining and Motion Simulating of the Indexing Mechanism with Globoidal Cam

2011 ◽  
Vol 381 ◽  
pp. 52-56
Author(s):  
Dai Zheng Fang ◽  
Gui Cheng Wang ◽  
Xiu Lian Li
Keyword(s):  
Contact Line ◽  
High Speed ◽  
High Speed Machining ◽  
Motion Simulation ◽  
Indexing Mechanism ◽  
Contour Surface ◽  
Matrix Operators

s. The work principle of indexing mechanism with globoidal cam is depicted firstly. Equations of the contour surface and the conjugate contact line are deduced by rotating matrix operators. The value of roughness becomes very small by high speed machining, so it can replace the grinding. At last, kinematics analyze and motion simulation are carried out.

Experimental Investigation of Micro-Scale Heat Transfer at an Evaporating Moving 3-Phase Contact Line

2010 ◽  
Author(s):  
K. Ibrahem ◽  
M. F. Abd Rabbo ◽  
T. Gambaryan-Roisman ◽  
P. Stephan
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Contact Line ◽  
High Speed ◽  
Local Maximum ◽  
Back Side ◽  
Phase Contact ◽  
Flat Plates ◽  
Maximum Heat ◽  
Micro Scale

An experimental study is conducted to investigate the micro-scale heat transfer at an evaporating moving 3-phase contact line. The moving evaporating meniscus is formed by pushing or sucking a liquid column of HFE7100 in a vertical channel of 600 μm width using a syringe pump. The gas atmosphere is pure HFE7100 vapor. This channel is built using two parallel flat plates. A 10 μm thick stainless steel heating foil forms a part of one of the flat plates. Two-dimensional micro-scale temperature field at the back side of the heating foil is observed with a high speed infrared camera with a spatial resolution of 14.8 μm × 14.8 μm and an in-situ calibration procedure is used at each pixel element. A high speed CMOS camera is used to capture the shape of the moving meniscus, the images are post-processed to track the free surface of the meniscus. Local heat fluxes from the heater to the evaporating meniscus are calculated from the measured transient wall temperature distributions using an energy balance for each pixel element. In the vicinity of the 3-phase contact line the heat flux distribution shows a local maximum due to high evaporation rates at this small region. The local maximum heat flux at the 3-phase contact line area is found to be dependent on the input heat flux, the velocity and the direction of the meniscus movement. The results give detailed insight into the specific dynamic micro-scale heat and fluid transport process.

Study on the Characteristics of Contact Line and Liquid Film in Rectangular Microgrooves Under Vibration Conditions

2011 ◽  
Author(s):  
Wei Cao ◽  
Xuegong Hu ◽  
Chaohong Guo ◽  
Dawei Tang
Keyword(s):  
Liquid Film ◽  
Contact Line ◽  
Heat Input ◽  
High Speed ◽  
Mechanical Vibration ◽  
Line Length ◽  
Oscillation Period ◽  
Wide Field ◽  
High Speed Camera ◽  
Phase Contact

With the help of a high-speed camera (30000 Frames/second) and a wide-field stereo-microscope, the effects of mechanical vibration on the meniscus film and triple-phase contact line in rectangular microgrooves were experimentally investigated. Distilled water was used as working liquid. The images of the oscillated meniscus film in an oscillation period were captured through the high speed camera and they were analyzed using a MATLAB program. The results show that as the vibration table moves upward, the length of contact line increases; as the vibration table moves downward, the length of contact-line decreases. During the oscillation, the axial liquid film spreads upward further along the microgrooves and the deformation of the contact line becomes more obvious. The increase of the triple-phase contact line length caused by the external mechanical vibration is helpful for contact line heat transfer enhancement. Besides, deformation curve of the contact line with and without heat input under different vibration conditions is similar, while the contact line with heat input is shorter.

Sign in / Sign up

Export Citation Format

Share Document