Effects of Different Liquid Properties on the Characteristics of Impact-Generated High-Speed Liquid Jets

2011 ◽  
Vol 110-116 ◽  
pp. 370-376 ◽  
Author(s):  
Anirut Matthujak ◽  
Chaidet Kasamnimitporn ◽  
Wuttichai Sittiwong ◽  
Kulachate Pianthong
Keyword(s):  
High Speed ◽  
Physical Property ◽  
Ambient Air ◽  
Video Camera ◽  
Orifice Diameter ◽  
Liquid Jets ◽  
Jet Formation ◽  
Digital Video Camera ◽  
Maximum Penetration ◽  
The Impact

This paper describes the study of high-speed liquid jets injected in air from an orifice. The main focus is to study the effect of different liquid properties on the characteristics of the high-speed liquid jets injected in ambient air. The high-speed liquid jets are generated by the impact of a projectile, which known as impact acceleration method, launched in a horizontal single-stage power gun (HSSPG). The conical nozzle of 30° angle with the orifice diameter of 0.7 mm was used to generate the jets. The characteristics of high-speed jets were visualized by the high-speed digital video camera with shadowgraph optical arrangement. From the shadowgraph images, the jet formation, atomization, vaporization and shock waves were obviously observed. The maximum averaged velocity of water, alcohol, n-hexane, chloroform and glycerin jets is estimated to be 1,669.03 m/s, 1,548.59 m/s, 1,420.44 m/s, 1,204.46 m/s and 1,496.97 m/s, respectively. That effect on the maximum penetration distance of the water jet is longer than that of all jets. Surface tension and latent heat are the significant physical property for jet formation, while density, kinematics viscosity and heat capacity are not.

Experimental Investigation of Droplet Dynamics on Solid Surfaces: Spreading and Recoil Effects

2006 ◽  
Author(s):  
Kalpak P. Gatne ◽  
Milind A. Jog ◽  
Raj M. Manglik
Keyword(s):  
Surface Tension ◽  
High Speed ◽  
Lower Surface ◽  
Video Camera ◽  
Temporal Variations ◽  
Liquid Viscosity ◽  
Viscous Effects ◽  
Droplet Dynamics ◽  
Digital Video Camera ◽  
The Impact

A study of the normal impact of liquid droplets on a dry horizontal substrate is presented in this paper. The impact dynamics, spreading and recoil behavior are captured using a high-speed digital video camera at 2000 frames per second. A digital image processing software was used to determine the drop spread and height of the liquid on the surface from each frame. To ascertain the effects of liquid viscosity and surface tension, experiments were conducted with four liquids (water, ethanol, propylene glycol and glycerin) that have vastly different fluid properties. Three different Weber numbers (20, 40, and 80) were considered by altering the height from which the drop is released. The high-speed photographs of impact, spreading and recoil are shown and the temporal variations of dimensionless drop spread and height are provided in the paper. The results show that changes in liquid viscosity and surface tension significantly affect the spreading and recoil behavior. For a fixed Weber number, lower surface tension promotes greater spreading and higher viscosity dampens spreading and recoil. Using a simple scale analysis of energy balance, it was found that the maximum spread factor varies as Re1/5 when liquid viscosity is high and viscous effects govern the spreading behavior.

Visualization of Supersonic Non-Newtonian Liquid Jets

2012 ◽  
Vol 187 ◽  
pp. 63-67
Author(s):  
Anirut Matthujak ◽  
Chaidet Kasamnimitporn ◽  
Wuttichai Sittiwong ◽  
Kulachate Pianthong
Keyword(s):  
High Speed ◽  
Ambient Air ◽  
Video Camera ◽  
Newtonian Liquid ◽  
Liquid Jets ◽  
Liquid Jet ◽  
Dynamic Behaviors ◽  
Penetration Distance ◽  
Jet Penetration ◽  
Jet Velocity

This paper describes the characteristics of supersonic non-Newtonian liquid jets injected in ambient air. The main focus is to visualize three types of time-independent non-Newtonian liquid jet and to describe their behaviors. Moreover, comparisons between their dynamic behaviors with Newtonian liquid jet are reported. The supersonic liquid jets are generated by impact driven method in a horizontal single-stage power gun. Jets have been visualized by the high speed digital video camera and shadowgraph method. Effects of different liquid types on the jet penetration distance, average jet velocity and other characteristics have been examined. From shadowgraph images, the unique dynamic behaviors of each non-Newtonian liquid jets are observed and found obviously different from that of the Newtonian liquid jet. The maximum average jet velocity of 1,802.18 m/s (Mach no. 5.30) has been obtained. The jet penetration distance and average velocity are significantly varied when the liquid types are different.

scholarly journals Detonation effects of shallow buried explosive in sandy soil on target plate acceleration in a small-scale blast test

2018 ◽  
Vol 192 ◽  
pp. 02028
Author(s):  
Hassan Zulkifli Abu ◽  
Ibrahim Aniza ◽  
Mohamad Nor Norazman
Keyword(s):  
Sandy Soil ◽  
High Speed ◽  
Early Stage ◽  
Time History ◽  
Video Camera ◽  
Small Scale ◽  
Target Plate ◽  
Air Blast ◽  
High Speed Video Camera ◽  
The Impact

Small-scale blast tests were carried out to observe and measure the influence of sandy soil towards explosive blast intensity. The tests were to simulate blast impact imparted by anti-vehicular landmine to a lightweight armoured vehicle (LAV). Time of occurrence of the three phases of detonation phase in soil with respect to upward translation time of the test apparatus were recorded using high-speed video camera. At the same time the target plate acceleration was measured using shock accelerometer. It was observed that target plate deformation took place at early stage of the detonation phase before the apparatus moved vertically upwards. Previous data of acceleration-time history and velocity-time history from air blast detonation were compared. It was observed that effects of soil funnelling on blast wave together with the impact from soil ejecta may have contributed to higher blast intensity that characterized detonation in soil, where detonation in soil demonstrated higher plate velocity compared to what occurred in air blast detonation.

Experimental Investigation on Contact Angle of Sintered Copper Powder Wick

2016 ◽  
Vol 819 ◽  
pp. 575-579 ◽  
Author(s):  
Nandy Putra ◽  
Iwan Setyawan ◽  
Dimas Raditya
Keyword(s):  
Contact Angle ◽  
Copper Powder ◽  
High Speed ◽  
Ambient Air ◽  
Video Camera ◽  
High Heat ◽  
High Heat Flux ◽  
Powder Particle Size ◽  
Air Exposure ◽  
Sintered Copper

Heat pipes are widely used in electronic cooling and other applications that require efficient transport or spreading of heat from local sources of high heat flux. One factor that most affect the performance of this device is the wetting properties of the wick material, whereby a hydrophilic wick material is required to transport the liquid from the evaporator to the condenser. The performance of heat pipe will decrease when the wick surface becomes hydrophobic as indicated by changes in its contact angle (CA). This study aims to determine the effect of ambient air exposure on the wettability of wick material. Wettability for a surface by a certain liquid can be shown by measuring the contact angle of liquid droplets on the surface. In this experiment, the contact angle was captured using a high speed video camera followed by image processing and then measured using Image J software. The surface of the sample/wick is a sintered copper powder which in this study through a process of forming or compaction by various parameters such as powder particle size, compacting pressure and sintering temperature. From the results of this study was found that the longer wicks were exposed in the ambient air, the contact angle of the liquid on the wick surface will be getting increased. After 7 days were contaminated on the ambient air, then all samples have been turned into hydrophobic, CA>90°.

A discussion on deformation of solids by the impact of liquids, and its relation to rain damage in aircraft and missiles, to blade erosion in steam turbines, and to cavitation erosion - The collapse of cavitation bubbles and the pressures thereby produced against solid boundaries

1966 ◽  
Vol 260 (1110) ◽  
pp. 221-240 ◽  
Keyword(s):  
Cavitation Erosion ◽  
Experimental Information ◽  
Liquid Jets ◽  
Steam Turbines ◽  
Jet Formation ◽  
Cavitation Damage ◽  
Cavity Collapse ◽  
New Ideas ◽  
The Impact ◽  
Shape Changes

Our object is to present a broad review of this subject as a branch of hydrodynamics, referring both to the well known ‘implosion’ mechanism first analysed by Lord Rayleigh and, more particularly, to the recently perceived possibility that effects of equally great violence, such as to damage solid boundaries, may arise through the impact of liquid jets formed by collapsing cavities. In §2 a few practical facts about cavitation damage are recalled by way of background, and then in §3 the significance of available theoretical and experimental information about cavity collapse is discussed. The main exposition of new ideas is in §4, which is a review of the factors contributing to shape changes and eventual jet formation by collapsing cavities. Finally, in §5, some new experimental observations on the unsymmetrical collapse of vapour-filled cavities are presented.

Effect of Hydrated Salt Additives on Film Boiling Behavior at Vapor Film Collapse

2008 ◽  
Author(s):  
Takahiro Arai ◽  
Masahiro Furuya
Keyword(s):  
High Speed ◽  
Video Camera ◽  
Film Boiling ◽  
Vapor Film ◽  
Quenching Temperature ◽  
Steel Sphere ◽  
Digital Video Camera ◽  
Collapse Temperature ◽  
Test Film ◽  
Film Collapse

A high-temperature stainless-steel sphere was immersed into various salt solutions to test film boiling behavior at vapor film collapse. The film boiling behavior around the sphere was observed with a high-speed digital-video camera. Because salt additives enhanced condensation heat transfer, the observed vapor film was thinner. Surface temperature of the sphere was measured. Salt additives increased the quenching (vapor film collapse) temperature, because frequency of direct contact between sphere surface and coolant increased. Quenching temperature rises with increased salt concentration. The quenching temperature, however, approaches a constant value when the slat concentration is close to its saturation concentration. The quenching temperature is well correlated with ion molar concentration, which is a number density of ions, regardless of the type of hydrated salts.

scholarly journals Investigation of an Ablation-dominated Arc in a Model Chamber by Optical Emission Spectroscopy

2017 ◽  
Vol 4 (2) ◽  
pp. 153-156 ◽  
Author(s):  
R. Methling ◽  
A. Khakpour ◽  
S. Wetzeler ◽  
D. Uhrlandt
Keyword(s):  
Emission Spectroscopy ◽  
High Speed ◽  
Optical Emission Spectroscopy ◽  
Rotational Symmetry ◽  
Line Emission ◽  
Optical Emission ◽  
Ambient Air ◽  
Video Camera ◽  
Radial Temperature ◽  
Model Chamber

A switching arc in a model chamber is investigated by means of optical emission spectroscopy. Ignition wire is applied to initiate an arc of several kiloampere between tungsten−copper electrodes. Radiation emitted by the arc plasma is absorbed by a surrounding PTFE nozzle, leading to an ablation–dominated discharge. Video spectroscopy is carried out using an imaging spectrometer combined with a high–speed video camera. Carbon ion and fluorine atom line emission from the heating channel as well as copper, oxygen and nitrogen from ignition wire and ambient air are analyzed with focus on the low–current phases at the beginning of discharge and near current zero. Additionally, electrical parameters and total pressure are recorded while the general behavior of the discharge is observed by another video camera. Considering rotational symmetry of the arc the corresponding radial emission coefficients are determined. Finally, radial temperature profiles are calculated.

EFFECT OF GEOMETRICAL PARAMETERS INTERACTION ON SWIRL EFFERVESCENT ATOMIZER SPRAY ANGLE

2015 ◽  
Vol 76 (9) ◽  
Author(s):  
Zulkifli Abdul Ghaffar ◽  
Salmiah Kasolang ◽  
Ahmad Hussein Abdul Hamid ◽  
Ow Chee Sheng ◽  
Mimi Azlina Abu Bakar
Keyword(s):  
High Speed ◽  
Video Camera ◽  
Spray Angle ◽  
Orifice Diameter ◽  
Working Fluid ◽  
Geometrical Parameters ◽  
High Speed Video Camera ◽  
Effervescent Atomizer ◽  
Vane Angle ◽  
Discharge Orifice

A wider spray angle produced by an atomizer is often required in providing a better spray dispersion. The formation and wideness of the spray angle were reported to be affected by the changes in geometrical parameters. In the present study, the effect of the interaction between two geometrical parameters (swirl-generating vane angle and discharge orifice diameter) on the swirl effervescent atomizer spray angle was studied. A newly-designed swirl effervescent atomizer was developed with 30°, 45° and 60° swirl-generating vane angle and 1.5, 2.0 and 2.5mm discharge orifice diameter. The atomizer performance tests were carried out using water as the working fluid and nitrogen gas as the atomizing agent. High-speed shadowgraph technique was deployed to record the resultant sprays produced. Video recordings, acquired using a high-speed video camera, were converted to a sequence of images for further analysis using image processing software. It was found that geometrical parameters of the newly designed atomizer have a great impact on the formation and characteristics of the spray angle. The combined effect of both swirl-generating vane angle and discharge orifice diameter has produced an increase in the spray angle. The largest spray angle was observed at the largest dimension of both geometries.

An Empirical Correlation for Maximum Penetration Depth of a Particle Impacting on a Free Surface at its Critical Velocity Condition

2011 ◽  
Vol 361-363 ◽  
pp. 320-323 ◽  
Author(s):  
Dong Mei Liu ◽  
Geoffrey Michael Evans ◽  
Qing Lin He
Keyword(s):  
Penetration Depth ◽  
Critical Condition ◽  
High Speed ◽  
Least Squares Method ◽  
Density Ratio ◽  
Video Camera ◽  
Empirical Correlation ◽  
Liquid Density ◽  
Maximum Penetration Depth ◽  
Maximum Penetration

Film flotation is a process which consumes much lower energy than mechanical cells. The extended film flotation technique is to separate mineral mixtures by different critical impact velocities. In this study the maximum penetration depth of a particle at its critical condition was investigated experimentally and theoretically. Experiments were performed using spherical glass beads of different diameters and hydrophobicities and different liquids. The penetration depth at critical condition was recorded and measured using high speed video camera. Buckingham’s PI theorem was applied to analyse the dimensionless groups, and then an empirical correlation for penetration depth was obtained by partial least squares method. It was found that the prediction results of the empirical equation were in good agreement with the measurements. Also, the influence factors were analysed. It was noticed that the hydrophobicities of particle and particle-liquid density ratio had most significant effects on the penetration depth.

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