Journal articles on the topic 'Splash phenomenon'
To see the other types of publications on this topic, follow the link: Splash phenomenon.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Splash phenomenon.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Song, Chen, Yuhua Pan, Ping Ma, Ming Zhao, and Tiancai Liu. "Numerical Simulation on the Influence of Submerged Combustion on Splashing and Heat Transfer in TSL Furnace." Metals 12, no. 2 (February 13, 2022): 328. http://dx.doi.org/10.3390/met12020328.
Full textAbstract:
Bath smelting technologies based on top submerged lance (TSL) injection have been widely used for pyrometallurgical metal production and solid waste treatment. In this work, a two-dimensional CFD simulation model of a pilot-scale 300 kg TSL furnace was established and applied to investigate the slag splashing phenomenon caused by submerged gas injection and combustion, with a special focus on the effect of submerged combustion on bubble formation, splash generation, splash distribution and heat transfer in the top space of the TSL furnace. The slag splash amount and distribution, and the temperature distribution characteristics inside the TSL furnace, especially under the influence of submerged combustion, were predicted, and influences of lance immersion depth and total injection gas flowrate on the splash behavior and heat transfer were investigated. As the lance immersion depth increases, more splashes are generated that distribute more evenly in the furnace top space and consequently heat transfer is enhanced. A larger injection gas flowrate generally increases the splash amount but the effect becomes weak when the injection gas flowrate exceeds a certain level, and there exists an appropriate range in injection gas flowrate for achieving the best heat transfer efficiency in TSL furnace.
2
Beczek, Michał, Magdalena Ryżak, Rafał Mazur, Agata Sochan, Cezary Polakowski, and Andrzej Bieganowski. "Influence of slope incline on the ejection of two-phase soil splashed material." PLOS ONE 17, no. 1 (January 7, 2022): e0262203. http://dx.doi.org/10.1371/journal.pone.0262203.
Full textAbstract:
Soil splash is the first step in the process of water erosion, where impacting raindrops cause the detachment and transport of soil material. One of the factors that strongly influences the magnitude of soil splash is the incline of the surface (slope). The aim of this study was to investigate the effect of the slope on the course of the splash phenomenon caused by single-drop impact (one drop impact per soil sample), with respect to the mass and proportions of the ejected material, taking into account its division into solid and liquid phases i.e. soil and water. The investigation was carried out using three types of soil with different textures, in moistened (pressure head corresponding to -1.0 kPa) and air-dry (-1500 kPa) conditions. The soil samples were on three angles of slope, being 5°, 15°, and 30°, respectively. After a single-drop impact with a diameter of 4.2 mm, the ejected material was collected using a splash cup. The following quantities of splashed material were measured: the total mass, the mass of the solid phase, and the mass of the liquid phase. Additionally, the distribution and proportions (soil/water) of the splashed material were analysed in both the upslope and downslope directions. It was found that: (i) the change of slope had a variable influence on the measured quantities for different soils; (ii) in the case of moistened samples, the measured values were mainly influenced by the texture, while in the dry samples, by the angle of the slope; (iii) with the increase of slope, the splashed material was mostly ejected in the downslope direction (irrespective of moisture conditions); (iv) in the moistened samples, the ejected material consisted mostly of water, while in the dry samples it was soil—this occurred for material ejected both upslope and downslope. The obtained results are important for improving the physical description of the process of splash erosion. A more thorough understanding and better recognition of the mechanisms governing this phenomenon at all stages could contribute to the development of more effective methods for protecting soil against erosion.
3
Beczek, Michał, Magdalena Ryżak, Agata Sochan, Rafał Mazur, and Andrzej Bieganowski. "The mass ratio of splashed particles during raindrop splash phenomenon on soil surface." Geoderma 347 (August 2019): 40–48. http://dx.doi.org/10.1016/j.geoderma.2019.03.028.
Full text
4
Sochan, Agata, Krzysztof Lamorski, and Andrzej Bieganowski. "Numerical Simulation and Experimental Study of the Drop Impact for a Multiphase System Formed by Two Immiscible Fluids." Sensors 22, no. 9 (April 19, 2022): 3126. http://dx.doi.org/10.3390/s22093126.
Full textAbstract:
The multiphase splash phenomenon is especially interesting in the context of environmental protection, as it could be a mechanism for transporting various types of pollution. A numerical 3D multiphase transport model was applied to a splash that occurred under the impact of a petrol drop on the water surface. The splash phenomenon in immiscible liquids was simulated using the multiphaseInterFoam solver, i.e., a part of the OpenFOAM computational fluid dynamics software implementing the finite volume method (FVM) for space discretization. Thirteen variants with a variable drop size (3.00–3.60 mm) or drop velocity (3.29–3.44 m/s) were conducted and validated experimentally based on splash images taken by a high-speed camera (2800 fps). Based on the numerical simulation, it was possible to analyse aspects that were difficult or impossible to achieve experimentally due to the limitations of the image analysis method. The aspects included the cavity spread, the jet forming moment, and, notably, the scale of the petroleum contamination spread in the splash effect. The simulations showed that droplets detaching from the crown did not consist of pure water but were mostly a “mixture” of water and petrol or petrol alone. The applied modelling workflow is an efficient way to simulate three-phase splash phenomena.
5
Meng, Yu, Shenglin Quan, Yali Guo, and Shengqiang Shen. "Comparative Analysis of Dynamic Behavior of Liquid Droplet Impacting Flat and Circular Wires." Energies 15, no. 18 (September 10, 2022): 6623. http://dx.doi.org/10.3390/en15186623.
Full textAbstract:
The performance of droplets captured by the wire mesh demister in a seawater desalination system seriously affects the quality of water desalination. Therefore, it is of great significance to study the droplet impact in the wire mesh demister to improve the demister’s efficiency. In this paper, a two-dimensional model of the droplet impacting the wire is established. The processes of the droplet impacting a flat wire and a circular wire are simulated by using the VOF model in Fluent, and a comparative analysis is conducted. The results demonstrate that both wires experience spreading and splashing stages, but when the wire is circular, the length of the lifted lamella is longer, the peak force on the wall is larger, the splash’s start time is earlier, and the number of secondary droplets is greater; the variation rule of the force on the wall caused by the change of initial velocity is similar, and the increase in initial velocity will promote the occurrence of splash phenomenon, but the role of the initial velocity on the splash effect is more obvious for the circular wire; and when the droplet impacts the flat wire, the influence of incident angle on the critical splash velocity is non-monotonic, but the critical splash velocity increases with an increase in incident angle when the wire is circular.
6
Sanz Garcia, Jose Manuel, Manuel Romana Garcia, and Jose Antonio Ramos Garcia. "Influence of Texture on Drainability, Splash and Spray in Flexible Pavements." Baltic Journal of Road and Bridge Engineering 16, no. 3 (September 29, 2021): 1–30. http://dx.doi.org/10.7250/bjrbe.2021-16.530.
Full textAbstract:
Although the splash and spray phenomenon produced by heavy trucks on road pavements is not a significant issue in relation to traffic safety, it may cause considerable inconveniences for those driving cars or motorbikes. This paper addresses the issue of pavement engineering with regard to surface characteristics; particularly pavement texture and its influence on water mobilization and projection in conditions of wet weather and heavy traffic. Considering the theoretical concept of pavement macrotexture, the analysis starts with the hypothesis concerning a relationship between Mean Profile Depth (MPD) and water splashed during rain. In order to focus on the impact of texture on splash and spray, a field experiment was carried out to test the hypothesis using 5 test tracks on a range of different pavement textures. The experiment was performed using a Traffic Speed Drain Meter (TSDM), which is a new drainability survey device presented to PIARC for approval. This equipment employs the laser and image technology and allows one to simultaneously obtain MPD and water splash data. The results of drainability and MPD were compared for each test track. Having analysed the pavements with different MPD ranges in the experiment, it has been concluded that MPD and water splashed apparently have an inversely proportional relationship. In addition, the TSDM proved to be a suitable equipment (repeatability) at an affordable cost (high performance of data collection). Finally, it has been concluded that there is a way to reduce splash and spray adjusting the infrastructure rather trying to solve the issue modifying vehicle moving modes. Therefore, if the issue is properly addressed by civil engineers and road managers, road safety in the areas of heavy rain may be improved at an affordable cost. The experiment presented here is considered a starting point opening the path for further research.
7
Andreotti, Riccardo, Sergio Abate, Andrea Casaroli, Mauro Quercia, Riccardo Fossati, and Marco V. Boniardi. "A Simplified ALE model for finite element simulation of ballistic impacts with bullet splash – development and experimental validation." Frattura ed Integrità Strutturale 15, no. 57 (June 22, 2021): 223–45. http://dx.doi.org/10.3221/igf-esis.57.17.
Full textAbstract:
An original simplified finite element model is proposed to simulate the effects of non-penetrating ballistic impacts causing the so-called bullet splash phenomenon (complete bullet fragmentation), while no fragmentation is caused to the target. The model is based on the Arbitrary Lagrangian Eulerian formulation (ALE) and it simulates the impact as a fluid-structure interaction. The bullet splash phenomenon has been tested by experimental analyses of AISI 304L plates impacted by 9x21 FMJ (full metal jacket) bullets. The model has been developed with the aim of creating a simplified approach to be used in the industry and forensic sciences to simulate the non-penetrating interaction of soft impactors with hard targets. Comparisons between evidence and simulation results lead to the conclusion that the proposed approach can be used in a conservative way to estimate both local and global effects of bullet-splash phenomena.
8
Ryżak, Magdalena, Andrzej Bieganowski, and Cezary Polakowski. "Effect of Soil Moisture Content on the Splash Phenomenon Reproducibility." PLOS ONE 10, no. 3 (March 18, 2015): e0119269. http://dx.doi.org/10.1371/journal.pone.0119269.
Full text
9
Papierowska, Ewa, Rafał Mazur, Tomasz Stańczyk, Michał Beczek, Joanna Szewińska, Agata Sochan, Magdalena Ryżak, Jan Szatyłowicz, and Andrzej Bieganowski. "Influence of leaf surface wettability on the drop splash phenomenon." Agricultural and Forest Meteorology 279 (December 2019): 107762. http://dx.doi.org/10.1016/j.agrformet.2019.107762.
Full text
10
van der Meer, Devaraj. "Wrapping up a century of splashes." Journal of Fluid Mechanics 800 (June 29, 2016): 1–4. http://dx.doi.org/10.1017/jfm.2016.328.
Full textAbstract:
Few fluid phenomena are as beautiful, fragile and ephemeral as the crown splash that is created by the impact of an object on a liquid. The crown-shaped phenomenon and the physics behind it have mesmerised and intrigued scientists for over a century, and still the scientific world has not yet uncovered all of the secrets of the splash. This is exemplified in a particularly striking manner in Marston et al. (J. Fluid Mech., vol. 794, 2016, pp. 506–529) where a 6 m tall vacuum chamber is employed to study the splash formed upon impact of a sphere onto a deep liquid pool, at both atmospheric and reduced ambient pressures. They shed light into the classical problem of the surface seal and study the buckling of the splash. With an almost magical touch they devise a method to create a splash without the liquid and the sphere ever coming into contact. The images that accompany the paper – taken with state-of-the-art high-speed cameras – are as stunning as the physics that is uncovered in them.
11
Ghosh, D., J. Roy, A. Ghosh, and A. Mukhopadhyay. "Directional Poissonic multiplicity distribution of protons ? Indication of side splash phenomenon." Zeitschrift f�r Physik A Atomic Nuclei 330, no. 3 (September 1988): 311–13. http://dx.doi.org/10.1007/bf01294875.
Full text
12
Beczek, M., M. Ryżak, A. Sochan, R. Mazur, C. Polakowski, D. Hess, and A. Bieganowski. "Methodological aspects of using high-speed cameras to quantify soil splash phenomenon." Geoderma 378 (November 2020): 114592. http://dx.doi.org/10.1016/j.geoderma.2020.114592.
Full text
13
TONG, R. P., W. P. SCHIFFERS, S. J. SHAW, J. R. BLAKE, and D. C. EMMONY. "The role of ‘splashing’ in the collapse of a laser-generated cavity near a rigid boundary." Journal of Fluid Mechanics 380 (February 10, 1999): 339–61. http://dx.doi.org/10.1017/s0022112098003589.
Full textAbstract:
Vapour cavities in liquid flows have long been associated with cavitation damage to nearby solid surfaces and it is thought that the final stage of collapse, when a high- speed liquid jet threads the cavity, plays a vital role in this process. The present study investigates this aspect of the motion of laser-generated cavities in a quiescent liquid when the distance (or stand-off) of the point of inception from a rigid boundary is between 0.8 and 1.2 times the maximum radius of the cavity. Numerical simulations using a boundary integral method with an incompressible liquid impact model provide a framework for the interpretation of the experimental results. It is observed that, within the given interval of the stand-off parameter, the peak pressures measured on the boundary at the first collapse of a cavity attain a local minimum, while at the same time there is an increase in the duration of the pressure pulse. This contrasts with a monotonic increase in the peak pressures as the stand-off is reduced, when the cavity inception point is outside the stated interval. This phenomenon is shown to be due to a splash effect which follows the impact of the liquid jet. Three cases are chosen to typify the splash interaction with the free surface of the collapsing cavity: (i) surface reconnection around the liquid jet; (ii) splash impact at the base of the liquid jet; (iii) thin film splash. Hydrodynamic pressures generated following splash impact are found to be much greater than those produced by the jet impact. The combination of splash impact and the emission of shock waves, together with the subsequent re-expansion, drives the flow around the toroidal cavity producing a distinctive double pressure peak.
14
Andreotti, Riccardo, Andrea Casaroli, Mauro Quercia, and Marco V. Boniardi. "A simplified formula to estimate the load history due to ballistic impacts with bullet splash. Development and validation for finite element simulation of 9x21mm full metal jacket bullets." Frattura ed Integrità Strutturale 16, no. 62 (September 22, 2022): 602–12. http://dx.doi.org/10.3221/igf-esis.62.41.
Full textAbstract:
An original simplified formula is proposed to estimate the load history caused by ballistic impacts characterized by the so-called bullet splash phenomenon, consisting in the complete bullet fragmentation with no penetration of the target. The formula is based on the progressive momentum variation of the mass of the bullet impacting on a planar plate normal to the impact direction. The method aims at creating a simplified approach to assess the response of structures by means of explicit finite element simulations without the need of modelling the interaction between impactor and target. The results demonstrate that the proposed method can be used to estimate the forces generated by bullet-splash phenomena of 9x21mm full metal jacket bullets and effectively applied to finite element simulations allowing significant reductions in computational cost.
15
Rein, Martin. "The transitional regime between coalescing and splashing drops." Journal of Fluid Mechanics 306 (January 10, 1996): 145–65. http://dx.doi.org/10.1017/s0022112096001267.
Full textAbstract:
A drop that falls into a deep liquid can either coalesce with the receiving liquid and form a vortex ring or splash. Which phenomenon actually occurs depends on the impact conditions. When the impact conditions are gradually changed the transition between coalescence and splashing proceeds via a number of intermediate steps. These are studied by means of high-speed photography of the normal impact of water drops on a plane water surface. The characteristics of different flows that appear in the transitional regime and possible mechanisms causing these flows are discussed in detail. The phenomena considered include the rise of thick jets and the ejection of high-rising thin jets out of the impact crater, the entrainment of gas bubbles, crater dynamics, crown formation and the generation of splash droplets. Finally, a classification of the phenomena characteristic of the transitional regime is given.
16
Laruelle, S., C. Fossier, C. Changenet, F. Ville, and S. Koechlin. "Experimental investigations and analysis on churning losses of splash lubricated spiral bevel gears." Mechanics & Industry 18, no. 4 (2017): 412. http://dx.doi.org/10.1051/meca/2017007.
Full textAbstract:
Churning losses are a complex phenomenon which generates significant power losses when considering splash lubrication of gear units. However, only few works deal with bevel gears dipped lubrication losses. The objective of this study is to provide a wide variety of experimental tests on churning losses, especially getting interested in geometry of spiral bevel gears influence. A specific test rig was used in order to study a single spiral bevel gear partially immersed in an oil bath. Experiments have been conducted for several operating conditions in terms of speeds, lubricants, temperatures and gear geometries to study their impact on splash lubrication power losses. These experimental results are compared with the predictions from various literature sources. As the results did not agree well with the predictions for all operating conditions, an extended equation derived from previous works is introduced to estimate churning losses of bevel gears.
17
Polakowski, C., M. Beczek, R. Mazur, A. Sochan, M. Ryżak, and A. Bieganowski. "The first report on the use of deuterium-labelled water in analysing the splash phenomenon." Journal of Hydrology 610 (July 2022): 127882. http://dx.doi.org/10.1016/j.jhydrol.2022.127882.
Full text
18
Allocca, L., L. Andreassi, and S. Ubertini. "Enhanced Splash Models for High Pressure Diesel Spray." Journal of Engineering for Gas Turbines and Power 129, no. 2 (September 4, 2006): 609–21. http://dx.doi.org/10.1115/1.2432891.
Full textAbstract:
Mixture preparation is a crucial aspect for the correct operation of modern direct injection (DI) Diesel engines as it greatly influences and alters the combustion process and, therefore, the exhaust emissions. The complete comprehension of the spray impingement phenomenon is a quite complete task and a mixed numerical-experimental approach has to be considered. On the modeling side, several studies can be found in the scientific literature but only in the last years complete multidimensional modeling has been developed and applied to engine simulations. Among the models available in literature, in this paper, the models by Bai and Gosman (Bai, C., and Gosman, A. D., 1995, SAE Technical Paper No. 950283) and by Lee et al. (Lee, S., and Ryou, H., 2000, Proceedings of the Eighth International Conference on Liquid Atomization and Spray Systems, Pasadena, CA, pp. 586–593; Lee, S., Ko, G. H., Ryas, H., and Hong, K. B., 2001, KSME Int. J., 15(7), pp. 951–961) have been selected and implemented in the KIVA-3V code. On the experimental side, the behavior of a Diesel impinging spray emerging from a common rail injection system (injection pressures of 80 and 120MPa) has been analyzed. The impinging spray has been lightened by a pulsed laser sheet generated from the second harmonic of a Nd-yttrium-aluminum-garnet laser. The images have been acquired by a charge coupled device camera at different times from the start of injection. Digital image processing software has enabled to extract the characteristic parameters of the impinging spray with respect to different operating conditions. The comparison of numerical and experimental data shows that both models should be modified in order to allow a proper simulation of the splash phenomena in modern Diesel engines. Then the numerical data in terms of radial growth, height and shape of the splash cloud, as predicted by modified versions of the models are compared to the experimental ones. Differences among the models are highlighted and discussed.
19
Bonmarin, P. "Geometric properties of deep-water breaking waves." Journal of Fluid Mechanics 209 (December 1989): 405–33. http://dx.doi.org/10.1017/s0022112089003162.
Full textAbstract:
The time-space evolution of a steep water wave reaching the breaking stage is observed by means of a visualization technique. In particular, the asymmetry of the wave profile in the near-breaking region is displayed. Measurements at breaking onset on a sample of breaking waves show a relation between the rate of asymmetry growth and the breaker type. The shape evolution of a plunging crest after breaking has started, and the related splash-up phenomenon and its part in the air-entrainment process are also observed.
20
Horbatenko, Yevhen. "The production of the splash phenomenon, as a way of dissipating the energy of a gravitational wave." Pidvodni tehnologii, no. 10 (July 1, 2020): 58–65. http://dx.doi.org/10.32347/uwt2020.10.1802.
Full text
21
Chiang, Chia-Ying, Tsung-Yu Yang, Alvin Casandra, and Shi-Yow Lin. "A study of the splash phenomenon of water drops on wood – Emitted droplet velocity and kinetic energy." Experimental Thermal and Fluid Science 88 (November 2017): 444–49. http://dx.doi.org/10.1016/j.expthermflusci.2017.06.019.
Full text
22
Zhong, Yuan, Haicun Du, Ying Zhang, Yue Chen, Qiang Liu, and Jie Huang. "Experimental research on dynamic characteristics of viscous droplets impacting rough solid surfaces at different temperatures." Canadian Journal of Physics 97, no. 12 (December 2019): 1288–300. http://dx.doi.org/10.1139/cjp-2018-0494.
Full textAbstract:
In view of different factors that influence dynamic behavior of a droplet impacting a solid surface, high-speed photography technology was used to capture oscillation processes and splash forms after changing seven kinds of physical properties, droplets impacting different roughness and temperature walls, and with different velocities and sizes. A physical model was established, and the theoretical value correlation of maximum spreading factor was derived to compare the theoretical analysis with experimental results. The effects of viscosity, surface tension, impact velocity, diameter of droplet, roughness, and temperature of the substrates on movement characteristics during the droplet’s impact on the wall surface were investigated. As the research indicates, the rebound and oscillatory phenomena of the fluid become more obvious with an increase in surface tension, and viscous force restricts the spreading of droplets. The higher the impact velocity, the greater the spreading factor at the same time, and the more pronounced the splashing phenomenon will be. The growth rate of maximum spreading factor (βmax) increases at first and then decreases with increasing initial diameter (d0) of the droplets. The smaller the d0, the more consistent the experimental results with the analytical solutions. The equilibrium contact angle (θe) of the droplet increases with surface roughness (Ra), whereas the surface wettability degrades. θe decreases with rising wall temperature. The increase of Ra promotes the “finger-like edge” and the splash motion of droplets; moreover, the critical velocity of splash declines with Ra. The optimum temperature (Tc) of a droplet impacting the high-temperature wall reduces with a decrease of Re. Furthermore, the greater the difference between wall temperature and Tc, the more significantly βmax changes. Droplet spreading is hindered on the low-temperature wall, and the lower Re is, the smaller the decrease in amplitude of βmax with dropping wall temperature.
23
Hu, Bai Song, Fan Zhang, Xin Liang Wang, Hui Peng Sun, and Xiao Ping Shi. "Experimental Study on the Liquid Distributor of Horizontal Tube Falling Film Evaporator." Advanced Materials Research 550-553 (July 2012): 2897–902. http://dx.doi.org/10.4028/www.scientific.net/amr.550-553.2897.
Full textAbstract:
A calandria liquid distributor device was designed for horizontal falling film evaporation. The guide plate was introduced in this, which is easy to manufacture and can effectively reduce splash phenomenon. This paper studies the liquid distribution from the relation between distributive unwell-distributed coefficient and liquid flux of distributor tube and distributor hole. The result showed that the distributive unwell-distributed coefficient of in liquid distributor was decreased along with accretion of liquid flux, as apposed to homogeneous perforated. The unwell-distributed hole coefficient of distributor tube No.0 was increased along with accretion of flux, as apposed to distributor tube No.1 and distributor tube No.2.
24
Cavazza, Luigi, Adriano Guarnieri, Angelo Fabbri, Chiara Cevoli, and Giovanni Molari. "Theoretical and experimental study on mechanical characterisation of a water drop impact on a solid surface." Journal of Agricultural Engineering 47, no. 1 (March 8, 2016): 12. http://dx.doi.org/10.4081/jae.2016.487.
Full textAbstract:
The drop impact phenomenon can be used to study many agricultural aspects related to the rainfall, runoff and irrigation, such as the stability of aggregated and the detachment of fine particles. The aim of this study was to study experimentally and numerically the water drop impact on a solid wall. In a first phase a simple experimental apparatus and basic theoretical concepts were used to investigate the influence of the drop speed on the impact pressure. In the second section, a finite element model able to reproduce the complex phenomenon observed in the experimental phase, was developed. The pressure values obtained by experimental measurement are similar to those calculated on the base of the energy conservation principle (average percentage difference of 15.6%). Numerical model was useful to obtain important information on pressure profile inside the drop and the impact pressure during the splash, at present hard to achieve experimentally. The model was used to estimate also an almost realistic dynamic behaviour of the spreading drop.
25
Bin Ramli, Mohd Syaifullah, Abdul Basit, Ku Zilati Ku Shaari, and Lau Kok Keong. "Study of the Effect of Surface Roughness on Droplet Spreading Behavior Using CFD Modeling." Applied Mechanics and Materials 625 (September 2014): 378–81. http://dx.doi.org/10.4028/www.scientific.net/amm.625.378.
Full textAbstract:
Water droplet spreading has been simulated at impact velocity of 3.0 m/s, 1.5 m/s and 0.5 m/s on surfaces with texture of ‘triangle’, ‘square’, ‘curve’ as well as smooth surface of aluminum. Higher impact velocity induced the droplet to spread faster and has a bigger diameter. At high impact velocity, spreading factor cannot be determined due to splashing and droplet break ups. In addition, at 1.5 m/s the phenomenon of splashing was found to be almost absent except on the surface with ‘square’ texture. ‘Square’ surface tends to splash earlier compared to other surfaces and is followed by ‘triangle’, ‘curve’ and smooth surface. At low impact velocity, the smooth surface has the highest spreading factor and followed by ‘triangle’, ‘square’ and ‘curve’ surface.
26
Fang, Long, and Guoding Chen. "Study of Morphology and Secondary Droplet Behaviors during Droplets Impacting on Static Hot Film." Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 38, no. 3 (June 2020): 494–500. http://dx.doi.org/10.1051/jnwpu/20203830494.
Full textAbstract:
The phenomenon of droplet impacting on hot film exists widely in nature and engineering applications. Considering limitations in current researches, an experimental setup to record the process of droplets impacting on hot film was built in this paper. Lots of experiments have been done and then the transitional threshold was established to determine impingement outcomes. The number of secondary droplets and the temperature of the secondary droplet are investigated based on the experimental results. The results show that impingement outcomes can be determined by the splashing parameter provided in this paper. The number of secondary droplets increases with the splash parameter, the probability distribution function of secondary droplet diameters follows the Weibull distribution. The temperature of secondary droplets is close to the hot film and almost all secondary droplets' temperature is above 90% of the hot film.
27
Wang, Xiao Bing. "Numerical Simulation of Three Dimensional Unsteady Flow of the Ruston Turbine in Stirred Tank." Advanced Materials Research 1008-1009 (August 2014): 906–9. http://dx.doi.org/10.4028/www.scientific.net/amr.1008-1009.906.
Full textAbstract:
Unsteady flow of a single six-blade ruston turbine in stirred tank is numerically simulated by using the large eddy simulation. Then the effect of the turbine installation position on mixing flow field is studied. The result shows that with a relatively low paddle installation position, mixing effect at the bottom of tank is obvious, while which go against the materials at the top layer mixing. When the paddle is installed at the top of the stirred tank, liquid splash and a concave downward liquid surface are easily caused. Finally the cavitation phenomenon is generated. When the paddle is installed from 1/3H to 2/3H, there are a uniform flow field distribution and higher average velocity flow. Large size vortex structures at the top and the bottom of the paddle are obvious which is beneficial to mix the materials.
28
LEE, CUNBIAO, HUAIWU PENG, HUIJING YUAN, JIEZHI WU, MINGDE ZHOU, and FAZLE HUSSAIN. "Experimental studies of surface waves inside a cylindrical container." Journal of Fluid Mechanics 677 (May 9, 2011): 39–62. http://dx.doi.org/10.1017/jfm.2011.43.
Full textAbstract:
We experimentally investigate the dynamics of surface waves excited by oscillations from a cylindrical sidewall. Particle-imaging-velocimetry measurements with fluorescent particles were used to determine the flow patterns near the sidewall of the cylindrical fluid container and to identify the locations of the evolving air–water interfaces. The high-frequency wall oscillations created four jets that originate at the cylindrical sidewall. Four vortex streets shed from the jets propagate from the sidewall to the centre of the container and subsequently excite a low-frequency gravity wave. The interaction between this gravitational surface wave and the high-frequency capillary waves was found to be responsible for creating droplet splash at the water surface. This phenomenon was first described as ‘Long-Xi’ or ‘dragon wash’ in ancient China. The physical processes for generating the droplet ejection, including the circular capillary waves, azimuthal waves, streaming jets and low-frequency gravity waves, are described in this paper.
29
Yang, Liu, Tang Wei, Liu Lisheng, Shao Junfeng, Shao Ming, and Cheng Xiangzheng. "Study on Heat Effect of High-Power Continuous Wave Laser on Steel Cylinder." Applied Sciences 10, no. 21 (November 5, 2020): 7844. http://dx.doi.org/10.3390/app10217844.
Full textAbstract:
This paper investigates the heat effects of continuous high-power lasers on steel cylinders. A theoretical model combining the mechanical characteristics and heat transfer of the steel cylinder that irradiated by a high-power laser is established. Simulations in temperature fields predict the varying heat effects on steel cylinders corresponding to different laser power levels, and more importantly, the thresholds of laser penetrations. The predictions are further validated by experimental tests, which use 1.5–2.8 kW laser irradiating on 7–15 mm thick steel cylinders. It has been found that the ablation mechanism of steel cylinder is primarily dependent on either the mass transfer of vaporized ablation or liquefied material under the action of vaporized back pressing. The present 0–300 s temperature field analyses show that steel melts at 1720 K and vaporizing ablation happens at 3250 K. It has also been observed that in the contact region between the laser and steel cylinder, the melting and vaporization accompanied by the interaction of the ablation process are followed by the sharp splash phenomenon.
30
Quiban, R., C. Changenet, Y. Marchesse, F. Ville, and J. Belmonte. "Churning losses of spiral bevel gears at high rotational speed." Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 234, no. 2 (June 25, 2019): 172–82. http://dx.doi.org/10.1177/1350650119858236.
Full textAbstract:
In the present study, no-load losses of different splash lubricated spiral bevel gears were measured. The authors used a specific test rig, and a set of gears, to investigate churning losses at higher tangential speeds: up to 60 m/s. An uncommon behavior of the drag torque was highlighted: the torque increased with the rotational speed until a local maximum was reached; then the torque decreased and a local minimum was noticed; at higher rotational speed the torque increased. The torque decrease seems to be linked with a windage phenomenon, which becomes non-negligible at such speeds. In this work, efforts were made to characterize this reduction of gear immersion depth in order to be able to predict no-load losses. It was found that the evolution of oil immersion was linked to a Froude number. Finally a new analytical model of no-load losses was developed for churning losses combined with windage effects. This formulation takes into account several parameters such as rotational speed, gear immersion depth, oil properties, and gear geometrical parameters.
31
Lubin, P., and S. Glockner. "Numerical simulations of three-dimensional plunging breaking waves: generation and evolution of aerated vortex filaments." Journal of Fluid Mechanics 767 (February 16, 2015): 364–93. http://dx.doi.org/10.1017/jfm.2015.62.
Full textAbstract:
AbstractThe scope of this work is to present and discuss the results obtained from simulating three-dimensional plunging breaking waves by solving the Navier–Stokes equations, in air and water. Recent progress in computational capabilities has allowed us to run fine three-dimensional simulations, giving us the opportunity to study for the first time fine vortex filaments generated during the early stage of the wave breaking phenomenon. To date, no experimental observations have been made in laboratories, and these structures have only been visualised in rare documentary footage (e.g. BBC 2009 South Pacific. Available on YouTube, 7BOhDaJH0m4). These fine coherent structures are three-dimensional streamwise vortical tubes, like vortex filaments, connecting the splash-up and the main tube of air, elongated in the main flow direction. The first part of the paper is devoted to the presentation of the model and numerical methods. The air entrainment occurring when waves break is then carefully described. Thanks to the high resolution of the grid, these fine elongated structures are simulated and explained.
32
Shi, Hong-Hui, Motoyuki Itoh, and Takuya Takami. "Optical Observation of the Supercavitation Induced by High-Speed Water Entry." Journal of Fluids Engineering 122, no. 4 (July 10, 2000): 806–10. http://dx.doi.org/10.1115/1.1310575.
Full textAbstract:
When a high-speed projectile penetrates into water, a cavity is formed behind the projectile. The gas enclosed in the cavity experiences a nonequilibrium process, i.e., the gas pressure decreases as the projectile moves more deeply into water. As a result, the cavity is sealed near the free surface (surface closure) and subsequently the cavity breaks up in water (deep closure). Accompanying the break-up of the cavity, secondary shock waves appear. This is the so-called supercavitation in water entry. This paper describes an experimental investigation into the water entry phenomenon. Projectiles of 342 m/s were generated from a small-bore rifle that was fixed vertically in the experimental facility. The projectiles were fired into a windowed water tank. A shadowgraph optical observation was performed to observe the entry process of the projectile and the formation and collapse of the cavity behind the projectile. A number of interesting observations relating to the motion of the free surface, the splash, the underwater bubbly flow and so on were found. [S0098-2202(00)00204-2]
33
Vaneetveld, G., Ahmed Rassili, Jacqueline Lecomte-Beckers, and H. V. Atkinson. "Thixoforging of 7075 Aluminium Alloys at High Solid Fraction." Solid State Phenomena 116-117 (October 2006): 762–65. http://dx.doi.org/10.4028/www.scientific.net/ssp.116-117.762.
Full textAbstract:
Thixoforging is a type of semi-solid metal processing at high solid fraction (0.5<fs<1), which involves the processing of alloys in the semi-solid state. 7075 alloy has been used as a feedstock for thixoforming in order to investigate thixoformability of a high performance aluminium alloy at high solid fraction. The microstructure in semi-solid state consists of fine spheroidal solid grains surrounded by liquid. Thixo behaviour allows laminar flow that avoids macro-porosity and other casting defects and gives better mechanical properties; so we can reduce the weight of functional parts. Higher solid fraction of 7075 alloy is less sensitive to temperature, avoids metal splash at high speed, allows laminar flow at high speed and gives a good smooth surface without stick-slip phenomenon. The process is quicker with less energy and so the production rate increases and the tool has longer life. However, high solid fraction promotes freezing flow because of faster solidification and the lack of liquid phase. This freezing flow creates solid/liquid segregation and increases the forming force.
34
Han, Z., Z. Xu, and N. Trigui. "Spray/wall interaction models for multidimensional engine simulation." International Journal of Engine Research 1, no. 1 (February 1, 2000): 127–46. http://dx.doi.org/10.1243/1468087001545308.
Full textAbstract:
Models were developed to describe the spray wall impingement processes that take place in internal combustion engines. In this report focus is placed on the model formulation and experiment assessment of the spray/wall interaction submodels. It is identified that the Leidenfrost phenomenon is very unlikely to occur in a spark ignition (SI) engine including stratified-charge operation in a direct injection spark ignition (DISI) engine. A more comprehensive splashing/deposition threshold function is proposed to include the effects of surface roughness and pre-existing liquid film. Based on the wave phenomena observed on the surface of the liquid crown formed during drop impingement, a new splash breakup model is developed using linear instability analysis. The predicted drop size agrees well with available single-drop impingement experimental data. A new formulation for the post-impingement droplet velocity is also given which uses statistical sampling and jet impingement theory. The proposed models were assessed by comparing computations with two sets of experimental sprays impinging on a flat plate with the use of a pintle nozzle injector for port fuel injection (PFI) engines. The computed spray shape, normal and tangential penetration and droplet size show good agreement with experimental data.
35
Williams, Hollis. "Superhydrophobic Sand Repels Water." Physics Teacher 61, no. 2 (February 2023): 138–39. http://dx.doi.org/10.1119/5.0065235.
Full textAbstract:
A key concept in current fluid dynamics and its applications to biology and technology is a phenomenon known as wetting. Wetting is familiar from everyday life and is simply the ability of a liquid to stay in contact with a solid surface. The wettability depends on the properties of the liquid and the solid and can be characterized by the static equilibrium contact angle θ (the angle at which the liquid–gas interface meets the liquid–solid interface). A contact angle below 90° indicates favorable wetting such that a drop of the liquid would spread over a large amount of the flat solid surface, whereas a high contact angle indicates that very little of the solid is wetted (this can be seen in Fig. 1, which shows various stages of surface wetting in terms of the equilibrium contact angle). Nevertheless, this theory generally sounds quite dry or difficult to visualize when explained to students for the first time. The theory of the contact angle also contains some controversies and has undergone some recent developments. We propose a simple classroom demonstration with superhydrophobic sand that gives a concrete visualization of “superhydrophobicity” and outline how the phenomenon can be explained macroscopically with wetting theory. There are several interesting physical effects that are due to superhydrophobicity: experimental studies have found, for example, that superhydrophobic spheres always splash when they impact a body of liquid. In terms of applications, there are various possibilities for water storage with superhydrophobic sand outlined in the chemistry literature.
36
Yang, S. H., S. Y. Jaw, and K. C. Yeh. "Cinematographic Analysis of Counter Jet Formation in a Single Cavitation Bubble Collapse Flow." Journal of Mechanics 27, no. 2 (June 2011): 253–66. http://dx.doi.org/10.1017/jmech.2011.29.
Full textAbstract:
ABSTRACTThis study utilized a U-shape platform device to generate a single cavitation bubble for the detail analysis of the flow field characteristics and the cause of the counter jet during the process of bubble collapse induced by pressure wave. A series of bubble collapse flows induced by pressure waves of different strengths are investigated by positioning the cavitation bubble at different stand-off distances to the solid boundary. It is found that the Kelvin-Helmholtz vortices are formed when the liquid jet induced by the pressure wave penetrates the bubble surface. If the bubble center to the solid boundary is within one to three times the bubble's radius, a stagnation ring will form on the boundary when impacted by the penetrated jet. The liquid inside the stagnation ring is squeezed toward the center of the ring to form a counter jet after the bubble collapses. At the critical position, where the bubble center from the solid boundary is about three times the bubble's radius, the bubble collapse flows will vary. Depending on the strengths of the pressure waves applied, either just the Kelvin-Helmholtz vortices form around the penetrated jet or the penetrated jet impacts the boundary directly to generate the stagnation ring and the counter jet flow. This phenomenon used the particle image velocimetry method can be clearly revealed the flow field variation of the counter jet. If the bubble surface is in contact with the solid boundary, the liquid jet can only splash radially without producing the stagnation ring and the counter jet. The complex phenomenon of cavitation bubble collapse flows are clearly manifested in this study.
37
Alaimo, Andrea, Mauro De Marchis, Gabriele Freni, Antonio Messineo, and Dario Ticali. "Concept of a New Pluviometer for Metering Rainfall Erosivity." Advanced Materials Research 452-453 (January 2012): 316–20. http://dx.doi.org/10.4028/www.scientific.net/amr.452-453.316.
Full textAbstract:
Rainfall is the main driver of several natural phenomena having a large impact on human activities. Its monitoring is then very important for natural disaster prevention and for the preservation of the environment. One important phenomenon is related to soil displacement due to rainfall impact. The intensity of physical soil degradation, detachment and transport of soil particles by raindrop splash and interrill erosion is largely controlled by rainfall characteristics. There is still a lot of debate as to whichparameter expresses the best rainfall erosivity. Due to the limited data ondrop-size distribution of natural rainfall and the time consuming nature of methods to obtain these data, rain erosivity parameters are commonly obtained from empirical relationships based on rainfall intensity. This paper describes an a new pluviometer able to measure several raindrop variables and assess rainfall kinetic energy at the impact with the ground. It enables one to measure drop size and drop velocity in real time and thus any parameter linked to rainfall erosivity. The pluviometer is based on the combination of optical and electrical sensors and it is based on cheap technologies in order to allow the easy distribution of several monitoring station on the analyzed area. A description of the device and of its sensor is presented in the present paper.
38
Figueiredo, Miguel, Guido Marseglia, Ana S. Moita, Miguel R. O. Panão, Ana P. C. Ribeiro, Carlo M. Medaglia, and António L. N. Moreira. "Thermofluid Characterization of Nanofluid Spray Cooling Combining Phase Doppler Interferometry with High-Speed Visualization and Time-Resolved IR Thermography." Energies 13, no. 22 (November 10, 2020): 5864. http://dx.doi.org/10.3390/en13225864.
Full textAbstract:
Spray impingement on smooth and heated surfaces is a highly complex thermofluid phenomenon present in several engineering applications. The combination of phase Doppler interferometry, high-speed visualization, and time-resolved infrared thermography allows characterizing the heat transfer and fluid dynamics involved. Particular emphasis is given to the use of nanofluids in sprays due to their potential to enhance the heat transfer mechanisms. The results for low nanoparticle concentrations (up to 1 wt.%) show that the surfactant added to water, required to stabilize the nanofluids and minimize particle clustering, affects the spray’s main characteristics. Namely, the surfactant decreases the liquid surface tension leading to a larger wetted area and wettability, promoting heat transfer between the surface and the liquid film. However, since lower surface tension also tends to enhance splash near the edges of the wetted area, the gold nanospheres act to lessen such disturbances due to an increase of the solutions’ viscosity, thus increasing the heat flux removed from the spray slightly. The experimental results obtained from this work demonstrate that the maximum heat convection coefficients evaluated for the nanofluids can be 9.8% to 21.9% higher than those obtained with the base fluid and 11.5% to 38.8% higher when compared with those obtained with DI water.
39
Golla, Siva Teja, K. Mayur, B. Venkatesham, and R. Banerjee. "Experimental study of sloshing noise in a partially filled rectangular tank under periodic excitation." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 233, no. 11 (November 12, 2018): 2891–902. http://dx.doi.org/10.1177/0954407018809300.
Full textAbstract:
Liquid sloshing is becoming a major source of noise in hybrid and high-end luxury cars, especially during acceleration/deceleration driving conditions. This is due to the reduction in noise from other sources, namely, engine, transmission system, road–tyre interaction and so on. Sloshing noise is highly dependent on fluid motion in the containers. Based on the fluid motion in the containers, sloshing is classified into different regimes. The present experimental study discusses the noise generation mechanisms for various sloshing regimes. It is done by emulating different sloshing regimes in a partially filled rectangular tank by imposing longitudinal periodic excitation. The effect of fill level on noise generation phenomenon in each regime is analysed, individually, using dynamic response parameters and high-speed camera images. In this study, the measured dynamic response parameters are pressure, force, acceleration and sound pressure levels as a function of time. The fundamental reasons for the cause of sloshing noise in partially filled rectangular tanks are identified in terms of fluid motion and its interaction with the surrounding objects. The excitations upto the sloshing resonance condition cause hydraulic jumps along the tank walls leading to hit noise. Excitations beyond the sloshing natural frequency cause the predominant interaction of surface waves with surrounding fluid leading to splash noise.
40
Djunaidi, Achmad, and Setiadi Aji Prawira. "TRADISI SIRAMAN (MEMANDIKAN CALON PENGANTIN) DALAM PROSESI UPACARA PERNIKAHAN ADAT JAWA DI DESA LARANGAN KECAMATAN LARANGAN KABUPATEN BREBES." CIVICUS : Pendidikan-Penelitian-Pengabdian Pendidikan Pancasila dan Kewarganegaraan 4, no. 1 (March 30, 2016): 43. http://dx.doi.org/10.31764/civicus.v4i1.324.
Full textAbstract:
Abstrak:Penelitian ini merupakan penelitian upacara adat jawa, yaitu upacara siraman. Dalam penelitian ini peneliti mengajukan rumusan masalah yang cukup menarik. Adapun rumusan masalah tersebut adalah bagaimana proses siraman serta apa makna siraman tersebut. Dengan tujuan memahami bagaimana proses siraman beserta makna yang terdapat dalam proses siraman. Metode penelitian yang digunakan adalah metode penelitian kualitatif. Penelitian kualitatif lebih bersifat deskriptif yang disusun secara sistematis dalam penelitian ini. Pendekatan yang digunakan adalah pendekatan fenomenolgi, karena metode ini memakai pengalaman hidup sebagai alat untuk memahami fenomena yang sedang terjadi ataupun yang sudah terjadi. Dalam penelitian ini juga menggunakan metode purposive sampling dimana peneliti menentukan sendiri sampel yang akan diambil karena pertimbangan tertentu. Metode pengumpulan data dalam penelitian ini yaitu metode observasi, wawancara, dan dokumentasi. Peneliti menganggap metode ini lebh efektif dalam penelitian kualitatif.Pembahasan proses upacara siraman berdasarkan hasil penelitian yang mendeskripsikan proses upacara siraman. Adapun proses dari siraman tersebut seperti berikut : calon pengantin memakai pakaian siraman lantas diiringi oleh orang tuanya ketempat siraman, orang tua calon pengantin yang menyiram dilanjutkan oleh sesepuh (orang yang dituakan) dan diakhiri dengan dukun pengantin memecahkan kendil siraman disambut para tamu yang mengucapkan “wes pecah pamore” . Selain proses upacara siraman, hasil penelitian juga membahas tentang makna yang terkandung dalam proses upacara siraman. Adapun makna yang terkandung dalam upacara siraman yaitu melakukan upacara adat (meminta berkah tuhan) sebagai bentuk harapan kesuksesan upacara pernikahannya, membersikan jasmani dan rohani sebagai bentuk penyucian diri untuk menghadapi upacara yang sakral serta pemberian doa yang terbaik dari keluarga dan para tamu undangan bagi calon pengantin. Abstract: This study is a Javanese traditional ceremony, the ceremony siraman. In this study, the researchers propose formulation of the problem is quite interesting. The formulation of the problem is how the siraman process and what the meaning of the siraman. With the goal of understanding how the process of being washed along with the meaning contained in the siraman process.The method used is a qualitative research method. Qualitative research is descriptive systematically arranged in this study. The approach used is phenomenological approach, because this method uses life experiences as a tool to understand the phenomenon that is happening or has already happened. In this research using purposive sampling method where researchers determine their own samples to be taken because of certain considerations. Methods of data collection in this research is the method of observation, interviews, and documentation. Researchers believe this method is more effective in qualitative research.Discussion ceremony siraman process based on research results that describe the process of being washed ceremony. The process of being washed in the following manner: the bride to wear a splash of water and then accompanied by his parents to place siraman, parents of prospective brides flush followed by the sesepuh (elder person) and ends with a splash kendil (water container)solve shaman bride greeted guests say “wes pecah pamore” (already glowing aura). Besides ceremonial siraman process, the results of the study also discusses the meaning contained in the process of being washed ceremony. As for the meaning contained in ceremonial splash of water that traditional ceremonies (ask for a blessing of god) as a form of hope of success wedding ceremony, cleaning physically and mentally as a form of self-purification to confront the ceremony of the sacred and the provision of prayer is the best of the family and invited guests for the bride.
41
Mohammad Karim, Alireza. "Physics of droplet impact on various substrates and its current advancements in interfacial science: A review." Journal of Applied Physics 133, no. 3 (January 21, 2023): 030701. http://dx.doi.org/10.1063/5.0130043.
Full textAbstract:
Droplet impact dynamics is an interfacial phenomenon that is shown everywhere in nature and is the underlying of numerous technological applications including bio-printing, tissue engineering, pharmaceuticals, fight against COVID-19 pandemic, smart biomaterials, and flexible electronics. Over the last decade, expeditious advancement of novel functional interfacial surfaces, high-speed visualization, nanoscience, nanotechnology, machine learning, and computational power, as well as the connection of flow physics with interfacial science, have contributed to enhancing the understanding of relevant complex physical phenomena. Droplet, upon impacting onto substrates, can deposit, spread, bounce, and splash. Features of droplet impact physics and surface wettability necessitate elaborate solid–liquid interactions. Given the significance of droplet impact physics for healthcare and electronics, it is recommended for the scientific community to direct research studies to profound the understanding of such complex physics. Therefore, this Review initially focuses on liquid–solid interfacial science. Second, droplet impact physics on numerous solid surfaces was discussed. Substrates with various wettability and physical features were considered: hydrophilic, hydrophobic, superhydrophobic, smooth, rough, and flexible elastic surfaces. Furthermore, numerous advancements of droplet impact on solid surfaces related to advanced technologies and challenges including printed electronics, smart biomaterials, tissue engineering, machine learning, and COVID-19 pandemic were reviewed. Finally, this Review outlines future perspectives and research directions in complex droplet impact physics.
42
Lücking, Robert, and Andrea Bernecker-Lücking. "Drip-tips do not impair the development of epiphyllous rain-forest lichen communities." Journal of Tropical Ecology 21, no. 2 (February 16, 2005): 171–77. http://dx.doi.org/10.1017/s0266467404002093.
Full textAbstract:
Drip-tips are a common phenomenon in tropical rain forests, often believed to facilitate drainage of water from the leaf surface and, in that way, reduce epiphyll growth. Some authors suggest a function in reducing splash soil erosion, leaching of substances from the leaf, and light reflectance, while other studies did not find any such correlations. We used an experimental approach to test for the effect of drip-tips on the development of epiphyllous lichen communities. Artificial leaves with and without pronounced drip-tips were exposed in a tropical lowland rain forest at La Selva Biological Station (Costa Rica) for a period of 38 mo, and the physical behaviour of rainwater was tested. On leaves with drip-tips, the water ran off in small, frequent drops 8–30 mm3 in size. On leaves without drip-tips, the water accumulated in the apex region and dripped off periodically in large drops 50–150 mm3 in size. Nevertheless, there was no significant difference in the development of epiphyllous lichen communities on leaves with and without drip-tips, in terms of area covered, species richness and composition. However, leaves without drip-tips had more debris accumulated in the apex region and, at the same time, fewer lichen species present in this region. Thus, while drip-tips do have an influence on how water is channelled off the leaf surface, they do not impair the development of epiphyllous lichen communities, except for the apex region where the presence of drip-tips does in fact enhance, not reduce, the establishment of lichens, by preventing the accumulation of debris. We conclude that, while drip-tips may have an ecological function, this function is unrelated to the development of epiphyllous lichen communities.
43
Mansoor, M. M., J. O. Marston, I. U. Vakarelski, and S. T. Thoroddsen. "Water entry without surface seal: extended cavity formation." Journal of Fluid Mechanics 743 (March 4, 2014): 295–326. http://dx.doi.org/10.1017/jfm.2014.35.
Full textAbstract:
AbstractWe report results from an experimental study of cavity formation during the impact of superhydrophobic spheres onto water. Using a simple splash-guard mechanism, we block the spray emerging during initial contact from closing thus eliminating the phenomenon known as ‘surface seal’, which typically occurs at Froude numbers $\mathit{Fr}= V_{0}^{2}/(gR_{0}) = O(100)$. As such, we are able to observe the evolution of a smooth cavity in a more extended parameter space than has been achieved in previous studies. Furthermore, by systematically varying the tank size and sphere diameter, we examine the influence of increasing wall effects on these guarded impact cavities and note the formation of surface undulations with wavelength $\lambda =O(10)~ \mathrm{cm}$ and acoustic waves $\lambda _{a}=O(D_{0})$ along the cavity interface, which produce multiple pinch-off points. Acoustic waves are initiated by pressure perturbations, which themselves are generated by the primary cavity pinch-off. Using high-speed particle image velocimetry (PIV) techniques we study the bulk fluid flow for the most constrained geometry and show the larger undulations ($\lambda =O (10~ \mathrm{cm}$)) have a fixed nature with respect to the lab frame. We show that previously deduced scalings for the normalized (primary) pinch-off location (ratio of pinch-off depth to sphere depth at pinch-off time), $H_{p}/H = 1/2$, and pinch-off time, $\tau \propto (R_{0}/g)^{1/2}$, do not hold for these extended cavities in the presence of strong wall effects (sphere-to-tank diameter ratio), $\epsilon = D_{0}/D_{tank} \gtrsim 1/16$. Instead, we find multiple distinct regimes for values of $H_{p}/H$ as the observed undulations are induced above the first pinch-off point as the impact speed increases. We also report observations of ‘kinked’ pinch-off points and the suppression of downward facing jets in the presence of wall effects. Surprisingly, upward facing jets emanating from first cavity pinch-off points evolve into a ‘flat’ structure at high impact speeds, both in the presence and absence of wall effects.
44
Zhang, Jiang-Feng, Xiao-Han Tian, Xiao-Ling Zhang, and Qing-Duan Meng. "Splashed gold bump dependence of cleavage of InSb chip under cyclic liquid nitrogen shocking tests." Acta Physica Sinica 71, no. 2 (2022): 028502. http://dx.doi.org/10.7498/aps.71.20211535.
Full textAbstract:
Local cleavage of indium antimonide (InSb) chip always occurs in the manufacture of the InSb infrared focal plane detectors (IRFPAs), and this specific fracture phenomenon restricts the improvement of the yield of the InSb IRFPAs. After analysis, we think that the cleavage of InSb chip in the edge region of the InSb IRFPAs is related to the splashed gold bump existing in this region, and this failure phenomenon dominates in the low-cyclic liquid nitrogen shocking tests. In order to clarify the influence of the splashed gold bump on the cleavage of the InSb chip, we establish a structural model of the InSb IRFPAs containing the splashed gold bump, and analyze the influence of the splashed gold bump on the thermal stress distribution in the InSb chip. Besides, we preset the initial cracks with different lengths at the stress concentration sites to describe the dislocations in InSb wafers. Using the energy release rate as criterion, we obtain the relationship between the cleavage of the InSb chip and the dislocation line length in the presence of splashed gold bump. The main conclusions are drawn as follows. 1) The influence of the splashed gold bump on the cleavage of the InSb chip is localized, and two stress concentration sites are formed in the outermost part of the contact region between the splashed gold bump and the InSb chip. 2) The energy release rate surrounding the preset crack increases promptly with the preset crack length increasing. 3) Cleavage of the InSb chip caused by the splashed gold bump belongs to the type I fracture failure mode. In the cyclic liquid nitrogen shocking tests, the dislocation line gradually punches through the InSb chip under the driving of the concentrating stress, and forms the macro cleavage of the InSb chip.
45
Грабарчук, О. Н., and Н. В. Рибачук. "ЮМОР В ПРОСТРАНСТВЕ СОВРЕМЕННОЙ УКРАИНСКОЙ КУЛЬТУРЫ." Humanities journal, no. 2 (October 29, 2018): 72–79. http://dx.doi.org/10.32620/gch.2018.2.08.
Full textAbstract:
An integral part of any person’s life is humor. It makes our life more attractive, it hides a huge potential of vitality, wherein humor is a risk zone, where it can be presented as something devastating and derogative.The last 4 years of the most difficult social and political processes of Ukrainian reality we can observe a splash of interest to humorous programs of various kinds. Several separate channels began its functioning by offering to view only comical and funny content. This phenomenon makes one to think about humor specifics, about necessity of interaction with the comic, about its importance not only for one person but for the whole country. Thus, the aim of the research is to determine the place of the humor in the contemporary Ukrainian culture.The humor subject is well represented in the history of the humanitarian sciences, however, due to the ambiguity of the subject of the study, this topic remains open for further researches. There are three main theories of humor, such as consolation theory, superiority theory and discrepancy theory. And each theory finds its own proponent.The main statement of the consolation theory is that humor is a way to cope with inner tension and the opportunity to get a pleasure from laughing. In the superiority theory the sense of satisfaction from the excellence while observing a fun person as a week, stupid, unsuccessful takes the first place. In the discrepancy theory the contrast between expected and real is important for understanding the humor nature, detecting the discrepancies of our ideas about things (concepts, categories) to its real embodiments, that in the end bring out the laugh. The success of the joke is the success of finding the hidden absurdity in it.Ukrainian science also provides some developments in this sphere. Annual scientific and theoretical conference devoted to the humor theme takes place in Odessa I. I. Mechnikov National University. The question of comical in human being and its cognition as well as forms of comical in literature and art are raised.To our mind, tragic social processes, which were taking place in Ukraine over the last 4 years, with no doubt lead to a rapid increase of society tension. In such conditions laugh is a good way to cope with negative consequences, as pointed in the consolation theory, humor and laugh are the opportunity to protect themselves painlessly, specifically Ukrainian society, from mental overload. As Freud pointed out, humor, irony and comic offer us a quick way not only to relieve tension, but also to get a pleasure, to live through the moment being happy. The moment of happiness and pleasure, the experience of consolation are the factors that determine the comical in the rank of priorities when choosing a particular discourse in conditions of the complex tragic situation.As any psychological protection the comical has two sides. To a certain moment, laugh is a relief from pain, as a result it becomes the cause of psychological anesthesia, the inability to fully experience the feelings and emotions that correspond to the situation context.However, this particularity of contemporary individual is connected not so with humor as with its overabundance. Also it is connected with overabundance of the information which is consumed in conditions of the informative society and society of consuming.On the other hand, humor supports Ukrainian society by contributing the stabilization of the social processes. Apparently, ironic discourse, which captured TV screens and Ukrainian YouTube, is the rescue for the Ukrainians and it proves one more time the ideas about consolation theory of humor.
46
Lahmar-Mebdoua, Y., A. Vardelle, Pierre Fauchais, and D. Gobin. "Heat Diffusion in Solidifying Alumina Splat Deposited on Solid Substrate under Plasma Sprayed Conditions: Application to Coating Formation." Defect and Diffusion Forum 297-301 (April 2010): 46–51. http://dx.doi.org/10.4028/www.scientific.net/ddf.297-301.46.
Full textAbstract:
A plasma-sprayed coating is built up by the layering of individual splats. The latter are formed by spreading and solidification of molten particles sprayed onto a solid substrate. The coating properties depend on its microstructure and the quality of contact between the splats and the underlying layer and between the piled-up splats. This work deals with a 1D model of heat transfer between plasma-sprayed alumina splat and smooth substrate. The model is based on heat diffusion in the solidifying splat and substrate and includes undercooling phenomenon, heterogeneous nucleation and crystal growth kinetics. It assumes that splat spreading and solidification are two independent processes. The model predicts splat cooling and solidification taking into account, as far as possible, the in-flight particle properties drawn from the literature in order to study their effect on splat thermal history. The effect of the quality of contact between the splats as well as the already-deposited and solidified layer thickness on the grain size distribution and front solidification velocity is investigated.
47
Jawad, Abdul, and Shamaila Rani. "Cosmological Evolution of Pilgrim Dark Energy inf(G)Gravity." Advances in High Energy Physics 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/952156.
Full textAbstract:
We analyze the behavior of pilgrim dark energy with Hubble horizon inf(G)gravity. We reconstruct thef(G)models through correspondence phenomenon by assuming two values of pilgrim dark energy parameter(u=2, -2). We evaluate the equation of state parameter which shows evolution of the universe in the quintessence, vacuum, and phantom phase for both cases ofuand give favor the pilgrim dark energy phenomenon. Also, squared speed of sound exhibits the stability off(G)model for both cases ofu. ThewPDE-wPDE′also provides freezing and thawing regions in this scenario. In this framework, ther-splane also corresponds to different dark energy scenarios.
48
Goldbaum, Dina, Richard R. Chromik, Nicolas Brodusch, and Raynald Gauvin. "Microstructure and Mechanical Properties of Ti Cold-Spray Splats Determined by Electron Channeling Contrast Imaging and Nanoindentation Mapping." Microscopy and Microanalysis 21, no. 3 (March 5, 2015): 570–81. http://dx.doi.org/10.1017/s1431927615000240.
Full textAbstract:
AbstractCold spray is a thermo-mechanical process where the velocity of the sprayed particles affects the deformation, bonding, and mechanical properties of the deposited material, in the form of splats or coatings. At high strain rates, the impact stresses are converted into heat, a phenomenon known as adiabatic shear, which leads to grain re-crystallization. Grain re-crystallization and growth are shown to have a direct impact on the mechanical properties of the cold-sprayed material. The present study ties the microstructural features within the cold-sprayed Ti splats and the substrate to the bonding mechanism and mechanical properties. High-resolution electron channeling contrast imaging, electron backscatter diffraction mapping, and nanoindentation were used to correlate the microstructure to the mechanical properties distribution within the titanium cold-spray splats. The formation of nanograins was observed at the titanium splat/substrate interface and contributed to metallurgical bonding. An increase in grain re-crystallization within the splat and substrate materials was observed with pre-heating of the substrate. In the substrate material, the predominant mechanism of deformation was twinning. A good relationship was found between the hardness and distribution of the twins within the substrate and the size distribution of the re-crystallized grains within the splats.
49
Ощепкова, Ольга Владимировна, and Светлана Александровна Тарасова. "FORMATION SPLOSS OF CADETS COLLECTIVES OF PENAL LAW INSTITUTE." Vestnik Samarskogo iuridicheskogo instituta, no. 1(37) (June 17, 2020): 111–18. http://dx.doi.org/10.37523/sui.2020.37.1.016.
Full textAbstract:
В статье констатируется, что формирование человека как личности невозможно без социума. Социум воздействует на человека через группу. Наивысший уровень группового развития характеризует группу как коллектив, в котором одним из основных признаков является групповая сплочённость. Сплочённость - это единство мнений членов группы по самым важным для неё вопросам, единство действий в существенных жизненных ситуациях. Сплоченность группы основывается на совместной предметной деятельности и включает эмоциональную, ценностную и поведенческую сферы личности. Формирование сплоченности коллектива курсантов - сотрудников пенитенциарной системы - проходит в специфических условиях, влияющих на процесс сплоченности. Это: казарменное положение курсантов, рождающее феномен «публичности» и феномен групповой изоляции; авторитарный стиль руководства. Нами было проведено исследование сплоченности коллектива курсантов юридического института ФСИН России, для чего были использованы методика Сишора «Определение индекса групповой сплоченности»; методика определения ценностно-ориентационного единства В.С. Ивашкина, В.В. Онуфриевой. Анализ полученных результатов позволил сформулировать рекомендации для устранения проблемных вопросов и повышения эффективности данного процесса: построение отношений как «по горизонтали», так и «по вертикали» на основе взаимного уважения и доверия; формирование осознанного понимания общности целей учебной и профессиональной деятельности; рациональное применение всех форм досуговой деятельности; гибкое сочетание авторитарного и демократического стилей руководства; строгое соблюдение этики деловых отношений курсантами, строевыми офицерами, профессорско-преподавательским составом, руководством; управление конфликтами и стрессами. The article states that the formation of man as an individual is impossible without society. Society affects man through the group. The highest level of development group characterizes the group as a collective, in which one of the main symptoms is group solidarity. Unity is the unity of views of members of the Group on the most important issues for her, delivering the most significant situations. Solidarity group is based on joint substantive work and includes emotional, moral and behavioral sphere of the individual. Formation cohesion team recruits-the personnel of the penitentiary system-specific conditions that affect social cohesion. It: barracking students where the phenomenon of «publicity» and the phenomenon of group isolation; the authoritarian leadership style. We conducted a study of the cohesion of the team of cadets of the FSIN Law Institute of Russia, for which The methodology of Sishor «Defining the Index of Group Cohesion» was used; V.V. Onufrieva). Analysis of the results made it possible to formulate recommendations to address problematic issues and improve the effectiveness of the process: building relationships both horizontally and vertically on the basis of mutual respect and trust; Building a conscious understanding of the commonality of the goals of academic and professional activities; Rational application of all forms of leisure activities; a flexible combination of authoritarian and democratic leadership styles; strict adherence to the ethics of business relations by cadets, military officers, faculty, leadership; conflict and stress management.
50
Puig-Centelles, Anna, Nicolau Sunyer, Oscar Ripolles, Miguel Chover, and Mateu Sbert. "Rain Simulation in Dynamic Scenes." International Journal of Creative Interfaces and Computer Graphics 2, no. 2 (July 2011): 23–36. http://dx.doi.org/10.4018/jcicg.2011070102.
Full textAbstract:
Rain is a complex phenomenon and its simulation is usually very costly. In this article, the authors propose a fully-GPU rain simulation based on the utilization of particle systems. The flexibility of CUDA allows the authors to include, aside from the rainfall simulation, a system for the detection and handling of the collisions of particles against the scenario. This detection system allows for the simulation of splashes at the same time. This system obtains a very high performance because of the hardware programming capabilities of CUDA.