Studies on Influence of Liquid Film Wave on Atomization and Wave Measurement

1989 ◽  
Author(s):  
Gan Xiaohua ◽  
Zhao Qishou
Keyword(s):  
Laser Pulse ◽  
Liquid Film ◽  
Size Distribution ◽  
High Speed ◽  
High Speed Photography ◽  
Phase Interaction ◽  
Spray Characteristics ◽  
Two Phase ◽  
Wave Measurement ◽  
Particle Sizer

In the present paper, two-phase interaction inside pre filming airblast atomizer and its influence on atomization are studied. Liquid film wave inside the atomizer is measured with techniques called resistance method and optics method, which are also developed herein. By the means of laser pulse micrography, high speed photography and laser particle sizer, disintegration and fluctuation of liquid wave are picturized and spray size SMD and size distribution parameter N are measured. Experiments show that liquid wave inside atomizer has important influence on spray characteristics.

Experimental Characterization of a Modified Airlift Pump

2014 ◽  
Author(s):  
Afshin Goharzadeh ◽  
Keegan Fernandes
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
High Speed ◽  
Water Flow Rate ◽  
High Speed Photography ◽  
Two Phase ◽  
Inner Diameter ◽  
Airlift Pump ◽  
Flow Map ◽  
Churn Flow

This paper presents an experimental investigation on a modified airlift pump. Experiments were undertaken as a function of air-water flow rate for two submergence ratios (ε=0.58 and 0.74), and two different riser geometries (i) straight pipe with a constant inner diameter of 19 mm and (ii) enlarged pipe with a sudden expanded diameter of 19 to 32 mm. These transparent vertical pipes, of 1 m length, were submerged in a transparent rectangular tank (0.45×0.45×1.1 m3). The compressed air was injected into the vertical pipe to lift the water from the reservoir. The flow map regime is established for both configurations and compared with previous studies. The two phase air-water flow structure at the expansion region is experimentally characterized. Pipeline geometry is found to have a significant influence on the output water flow rate. Using high speed photography and electrical conductivity probes, new flow regimes, such as “slug to churn” and “annular to churn” flow, are observed and their influence on the output water flow rate and efficiency are discussed. These experimental results provide fundamental insights into the physics of modified airlift pump.

Age-Related Differences in Throwing Techniques Used by the Catcher in Baseball

1994 ◽  
Vol 6 (3) ◽  
pp. 225-235 ◽  
Author(s):  
Shinji Sakurai ◽  
Bruce Elliott ◽  
J. Robert Grove
Keyword(s):  
High Speed ◽  
High Performance ◽  
Age Groups ◽  
Three Dimensional ◽  
Transformation Method ◽  
High Speed Photography ◽  
Two Phase ◽  
Ball Speed ◽  
Age Related ◽  
Release Speed

Three-dimensional (3-D) high speed photography was used to record the overarm throwing actions of five open-age, four 18-year-old, six 16-year- old, and six 14-year-old high-performance baseball catchers. The direct linear transformation method was used for 3-D space reconstruction from 2-D images of the catchers throwing from home plate to second base recorded using two phase-locked cameras operating at a nominal rate of 200 Hz. Selected physical capacity measures were also recorded and correlated with ball release speed. In general, anthropometric and strength measures significantly increased through the 14-year-old to open-age classifications, while a range of correlation coefficients from .50 to .84 was recorded between these physical capacities and ball speed at release. While many aspects of the kinematic data at release were similar, the key factors of release angle and release speed varied for the different age groups.

Experimental Characterization of Two-Phase Swirl Flow Interacting With a Circular Bluff Body

2021 ◽  
Author(s):  
Rafael Gonzalez Hernandez ◽  
Afshin Goharzadeh ◽  
Mahmoud Meribout ◽  
Lyes Khezzar
Keyword(s):  
High Speed ◽  
Bluff Body ◽  
Transition Period ◽  
Swirl Flow ◽  
Critical Distance ◽  
High Speed Photography ◽  
Flow Loop ◽  
Two Phase ◽  
Air Pocket ◽  
Air Core

Abstract This study presents an experimental investigation of two-phase swirl flow interacting with a circular bluff body. A horizontal and transparent multiphase flow loop is employed to investigate the dynamic of swirl flow close to the circular bluff body. Using high-speed photography, air-core development during the transition period is characterized. Analysis of both instantaneous and averaged images provides key information on air-core length and diameter for steady state conditions. The distance from air-core tip to the disk depends on a critical gas-liquid ratio (GLRc). The presence of air pocket behind the circular bluff body depends on a critical distance to the disk.

Simulation of jet velocity in the melt-blowing process using the coupled air–polymer model

2018 ◽  
Vol 89 (16) ◽  
pp. 3221-3233 ◽  
Author(s):  
Xibo Hao ◽  
Hui Huang ◽  
Yongchun Zeng
Keyword(s):  
High Speed ◽  
Flow Model ◽  
Processing Parameters ◽  
High Speed Photography ◽  
Critical Factors ◽  
Polymer Model ◽  
Melt Blowing ◽  
Two Phase ◽  
Jet Velocity ◽  
Jet Velocities

The polymer jet velocity is one of the most basic and critical factors in the melt-blowing process and has always been difficult to measure online. Much effort has been made on the numerical prediction of the jet velocity. However, little work has involved the complex interaction between the air flow and the polymer. Here, the Level-Set method is used to develop the coupled air–polymer two-phase flow model, and to simulate the polymer jet motion in the melt-blowing process considering the coupled effect of the air and polymer. Meanwhile, high-speed photography is adopted in the experiments to verify the simulation results. The x- and y-components of the jet velocities and the whipping amplitude of the jet motion are discussed. The rapid increase of jet velocity and the decrease of jet diameter show that most attenuation of the polymer jet occurred within a distance close to the die (10 mm). Based on the model, the effects of the processing parameters on the jet velocity are examined numerically.

In situ characterisation of size distribution and rise velocity of microbubbles by high-speed photography

2020 ◽  
Vol 225 ◽  
pp. 115836 ◽  
Author(s):  
Bert Swart ◽  
Yubin Zhao ◽  
Mohammed Khaku ◽  
Eric Che ◽  
Richard Maltby ◽  
...  
Keyword(s):  
Size Distribution ◽  
High Speed ◽  
High Speed Photography ◽  
Rise Velocity

Study on atomization particle size characteristics of two-phase flow nozzle

2021 ◽  
pp. 1-12
Author(s):  
Haoqi Lilan ◽  
Junbin Qian ◽  
Nan Pan
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Droplet Size ◽  
High Speed ◽  
Droplet Size Distribution ◽  
Average Diameter ◽  
Spray Atomization ◽  
Two Phase ◽  
Nozzle Pressure ◽  
Local Observation

Nozzle spray atomization is widely used in industrial and agricultural production processes and is a very complicated physical change. The spray atomization of the nozzle is a process in which the droplets are continuously broken into finer particles under the action of force, in order to study the effect of nozzle atomization, that is, droplet size distribution characteristics. The experimental average mathematical model of droplet size distribution was established by introducing the average diameter of Sutter (SMD). The droplet size distribution in the atomization field of the nozzle is studied by simulation. In the experimental study, the high-speed camera, external mixing air atomizing nozzle platform experimental device and image processing were used, and the atomization field was divided into multiple observation areas. Through the measurement of several local observation areas, the droplet size distribution of the whole atomization field is constructed. It provides a reference for the study of the atomization field of the nozzle and a basis for the intuitive understanding of the droplet size distribution in the atomization field of the nozzle. The effective atomization area of the nozzle atomization was selected to study the influence of the liquid flow rate, the liquid temperature and the nozzle pressure on the atomized particle size distribution of the externally mixed atomizing nozzle. The internal law is obtained, which provides a basis and reference for effectively controlling the atomization effect in the atomization field.

scholarly journals Formation and rupture of gas film of antibubble

2020 ◽  
Vol 23 (1) ◽  
pp. 91-104
Author(s):  
Lichun Bai ◽  
Jinguang Sun ◽  
Zhijie Zeng ◽  
Yuhang Ma ◽  
Lixin Bai
Keyword(s):  
Liquid Film ◽  
High Speed ◽  
Liquid Surface ◽  
Single Layer ◽  
Liquid Films ◽  
Droplet Impact ◽  
Liquid Interface ◽  
High Speed Photography ◽  
Merging Process ◽  
The Impact

The formation and rupture of gas film in the process of formation, rupture and coalescence of antibubbles were investigated by high-speed photography. It was found that a gas film will appear and wrap a droplet when the droplet hit a layer of liquid film or foam before impacting the gas-liquid interface. The gas film may survive the impact on the gas-liquid interface and act as the gas film of an antibubble. A multilayer droplet will be formed when the droplet hits through several layer of liquid films, and a multilayer antibubble will be formed when the multilayer droplet impact a gas-liquid interface or a single layer of foam on the liquid surface. The way to generate antibubbles by liquid films will undergo the formation and rupture of gas films. The coalescence of two antibubbles, which shows a similar merging process of soap bubbles, also undergo the rupture and formation of gas films. The rupture of gas film of antibubble caused by aging and impact is also discussed.

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