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Influence of Viscosity in Fluid Atomization with Surface Acoustic Waves  [PDF]
Andreas Winkler, Paul Bergelt, Lars Hillemann, Siegfried Menzel
Open Journal of Acoustics (OJA) , 2016, DOI: 10.4236/oja.2016.63003
Abstract: In this work, aqueous glycerol solutions are atomized to investigate the influence of the viscosity on the droplet size and the general atomization behavior in a setup using standing surface acoustic waves (sSAW) and a fluid supply at the boundary of the acoustic path. Depending on the fluid viscosity, the produced aerosols have a monomodal or polymodal size distribution. The mean droplet size in the dominant droplet fraction, however, decreases with increasing viscosity. Our results also indicate that the local wavefield conditions are crucial for the atomization process.
Experimental Investigation of Influence of Acoustic Wave on Vapour Precipitation Process
V. Vekteris,I. Tetsman,V. Moksin
Engineering, Technology & Applied Science Research , 2013,
Abstract: The measurement results of acoustic field parameters above electroplating bath, in presence of water vapour, are analyzed in this work. Suction was created by means of side exhausters. It is obtained that the sound field generator generated a sound level of 130–140 dB at frequency interval between 1 and 10 kHz. It is shown that aerosol coagulation and precipitation processes are intensified under the mentioned conditions. The concentration of vapour and other aerosols in removal air decreases as a result, therefore air cleaning equipment costs can be reduced and cleaning efficiency increased.
Improving Network Efficiency by Removing Energy Holes in WSNs  [PDF]
M. B. Rasheedl,N. Javaid,A. Javaid,M. A. Khan,S. H. Bouk,Z. A. Khan
Computer Science , 2013,
Abstract: Cluster based Wireless Sensor Networks (WSNs) have been widely used for better performance in terms of energy efficiency. Efficient use of energy is challenging task of designing these protocols. Energy holedare created due to quickly drain the energy of a few nodes due to non-uniform distribution in the network. Normally, energy holes make the data routing failure when nodes transmit data back to the base station. We proposedEnergy-efficient HOleRemoving Mechanism (E-HORM) technique to remove energy holes. In this technique, we use sleep and awake mechanism for sensor nodes to save energy. This approach finds the maximum distance node to calculate the maximum energy for data transmission. We considered it as a threshold energy Eth. Every node first checks its energy level for data transmission. If the energy level is less than Eth, it cannot transmit data. We also explain mathematically the energy consumption and average energy saving of sensor nodes in each round. Extensive simulations showed that when use this approach for WSNs significantly helps to extend the network lifetime and stability period.
Numerical simulation of acoustic wake effect in acoustic agglomeration under Oseen flow condition
GuangXue Zhang,JianZhong Liu,Jie Wang,JunHu Zhou,KeFa Cen
Chinese Science Bulletin , 2012, DOI: 10.1007/s11434-012-5212-1
Abstract: We numerically simulate the hydrodynamic interaction of aerosol particles due to the acoustic wake effect under the Oseen flow condition. Attraction is found for two nearby particles with an orientation angle of 0 to 50° with respect to the acoustic field, and weak repulsion is found outside this range. Good agreement is obtained between the numerical results and experiments in the literature. We study the influence of particle size, sound wave frequency and the particle separation. The result shows that the acoustic wake effect plays a significant role in acoustic agglomeration. It could be either the major agglomeration mechanism of monodisperse aerosols or the major refill mechanism for polydisperse aerosols to supplement orthokinetic interaction.
International Journal of Engineering Science and Technology , 2011,
Abstract: Air braking system is one of the critical component in ensuring the safety of the commercial vehicle. Quality of air supplied to the brake system should be dry and free form impurities. Some amountof lubrication oil of the compressor will get carried along with the compressed air. Oil which was carried away will be in the form of aerosols. These oil aerosols will reduce the absorptive capacity of the desiccant of air dryer, wear out of valves of brake chamber and also erode system components. This work focus on developing a concept to remove the oil aerosols. Multiphase CFD simulation has been carried out to find the efficiency of filter in removing the oil aerosols, and pressure drop across the filter. This work also includes developing a prototype of filter and performing experimental analysis. Both the results of CFD analysis as well as the experimental analysis are matching.
Research on the Influence of an Acoustic Field on Particle Cohesion in Liquid
Ramūnas Vilki?ius,Andrius Styra,Vladas Vekteris
Science – Future of Lithuania , 2012,
Abstract: Iron is one of the most common natural elements. When iron concentration in water is more than 0,3 mg/l, it causes the formation of rust drain tag or changes the colour of the fabric during washing. Thus, the use of the acoustic field to improve water quality is a very relevant topic. Acoustic oscillations are currently widely used in various industrial sectors, including water treatment, metallurgy, chemical and food industry, equipment manufacturing and medicine. When materials are affected by acoustic fields, physical-chemical processes begin. Acoustic fields cause material dispersion, emulsification, coagulation and degassing (gas removal) as well as influence the crystallization and melting processes. Acoustic vibrations may also cause various chemical transformations such as oxidation, polymerization processes and depolymerisation. The utilization of acoustics to enhance water oxidation and precipitation of coarse impurities further extends the scope of the use of this physical method.Article in Lithuanian
Influence of aerosols on the formation and development of radiation fog  [PDF]
J. Rangognio,P. Tulet,T. Bergot,L. Gomes
Atmospheric Chemistry and Physics Discussions , 2009,
Abstract: This paper assesses the impact of aerosol properties on the formation and the development of radiation fog. Simulations were performed using the Meso-NH meteorological model including the ORILAM aerosol scheme coupled with a two-moment microphysical cloud scheme (number concentration of cloud droplets and cloud water content). The activation scheme used was taken from the work of Abdul-Razzak and Ghan (2004). "Off-line" sensitivity analysis of CCN (Cloud Condensation Nuclei) activation was performed on number, median diameter and chemical compounds of aerosols. During this "off-line" study, the interactions with the other physical processes (e.g. radiative) were not taken into account since the cooling rate was imposed. Different regimes of CCN activation and a critical value of aerosol number concentration were found. This critical aerosol number corresponds to the maximum of activated cloud droplets for a given cooling rate and given aerosol chemical properties. As long as the aerosol number concentration is below this critical value, the cloud droplet number increases when the aerosol number increases. But when the aerosol number concentration exceeds this critical value, the cloud droplet number decreases when aerosol number increases. A sensitivity study on aerosol chemical composition showed that the CCN activation was limited in the case of hydrophilic aerosol composed of material with a solubility in the 10% range. An event observed during the ParisFOG field experiment was simulated. This case took place in the polluted sub-urban area of Paris (France) characterized by particle concentrations of 17 000 aerosols per cm3. 1D simulations successfully reproduced the observed temporal evolution of the fog layer. Beyond the initial fog formation at the surface, cloud droplet formation occurred at the top of the fog layer where the cooling rate was maximum, reaching more than 10 K h 1. These simulations confirm that the aerosol particle number concentration is a key parameter for the accurate prediction of the microphysical properties of a fog layer and also influences the vertical development of fog. The important of the interaction between microphysical and radiative processes is illustrated, showing how the life cycle of a fog layer is determined by the CCN number concentration and chemical properties.
Revista Romana de Economie , 2006,
Abstract: Energy efficiency is correlated with many factors of influence: Gross National Income per capita, energy imports (% of energy use), renewable combustible and waste (% of total), energy use per capita, services as % of GDP and others. In this paper we are testing a model of piecewise linear regression with breakpoint in order to measure the influence of these factors on the variation of GDP per unit of energy use in Europe in the year 2003.
Power Efficiency Calculation of Acoustic Energy Transmission by a Stepped-Plate Radiator  [PDF]
Yonghwan Hwang, Wonkyu Moon
Energy and Power Engineering (EPE) , 2017, DOI: 10.4236/epe.2017.94016
Abstract: One performance measure of in-air ultrasonic radiators, such as wireless power transmission, is the power efficiency of the transducers. The efficiency of most in-air acoustic radiators is low, even at ultrasonic frequencies; however, a large radiating plate with steps introduced by Gallego-Juarez et al., can provide efficient radiation. Their in-air acoustic radiator consists of a Langevin transducer for wave excitation, a mechanical amplifier, and a stepped plate with a large radiating area. This study describes a design processing technique for a stepped-plate radiator developed for optimum energy transmission at the target point in air. The total efficiency required to transfer the acoustic energy was divided into three categories, and the design parameters of each category were calculated to maximize the efficiency. This design technique allows optimum acoustic radiation efficiency and maximum acoustic energy transmission depending on various acoustic energy transfer conditions.
Anisotropy of DC Electric Field Influence on Acoustic Wave Propagation in Piezoelectric Plate  [PDF]
S. I. Burkov,O. P. Zolotova,B. P. Sorokin,K. S. Aleksandrov
Physics , 2010,
Abstract: Anisotropy of dc electric field influence on the different types of acoustic waves in piezoelectric plate has been investigated by means of computer simulation. Detail calculations have made for bismuth germanium oxide crystals.
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