A method for containerless ‘liquid-phase processing was developed which has practical application in process and property research on virtually any material which is involatile at the melting point. It combines aerodynamic and acoustic forces to support and position the levitated material. The design provides forced convection control of the thermal boundary in the gas surrounding beam-heated specimens, which stabilizes the acoustic forces and allows acoustic ......
A method for containerless ‘liquid-phase processing was developed which has practical application in process and property research on virtually any material which is involatile at the melting point. It combines aerodynamic and acoustic forces to support and position the levitated material. The design provides forced convection control of the thermal boundary in the gas surrounding beam-heated specimens, which stabilizes the acoustic forces and allows acoustic ......
详见文章详情。[详细]
This paper introduces a simplified analytical model describing the governing dynamics of near-field acoustically levitated objects. The simplification converts the equation of motion coupled with the partial differential equation of a compressible fluid, into a compact, second order ordinary differential equation, where the local stiffness and damping are transparent. The simplified model allows one to more easily analyse and design near-field acoustic levitation based systems, and it also helps[详细]
The modelling of evaporation in which droplet geometry deviates from sphericity, i.e., oblate spheroid, when the droplet experiences high dynamic stresses or a high Weber number, is important in many applications. The validation of such theoretical models is often difficult to achieve experimentally. The acoustic levitation technique was used to investigate the evaporation of an oblate spheroid for different liquids. Evaporation of oblate droplet at constant aspect ratio is realized......[详细]
The contactless coalescence of a droplet is of paramount importance for physical and industrial applications. This paper describes a coalescence method to be used mid-air via acoustic levitation using an ultrasonic phased array system. Acoustic levitation using ultrasonic phased arrays provides promising lab-on-a-drop applications, such as transportation, coalescence, mixing, separation, evaporation, and extraction in a continuous operation. The mechanism of droplet coalescence in mid-air......[详细]
A new method utilizing an acoustic levitation technique is introduced to measure liquid surface tension. During the measurement a small drop of test liquid is acoustically levitated in air, and its static shape is gauged with the variation of its altitude location. The experimental data are matched with theoretical calculations giving an estimation of liquid surface tension......[详细]
The modelling of evaporation in which droplet geometry deviates from sphericity, i.e., oblate spheroid, when the droplet experiences high dynamic stresses or a high Weber number, is important in many applications. The validation of such theoretical models is often difficult to achieve experimentally. The acoustic levitation technique was used to investigate the evaporation of an oblate spheroid for different liquids......[详细]
Viscosity measurements with CO 2 -saturated squalane with three different methods, a novel and two classical ones, are compared in a range of pressure from 0.1 MPa to 10.1 MPa at temperatures of 313 K, 333 K and 353K. The dynamic viscosities were measured using an acoustic levitator developed for measurements under pressure, a capillary viscometer and a rotational viscometer. Squalane is saturated with CO 2 at each pressure and temperature measured. It is shown......[详细]
An experimental technique is demonstrated for acoustically levitating aqueous foam drops and exciting their spheroidal modes. This allows fundamental studies of foam-drop dynamics that provide an alternative means of estimating the viscoelastic properties of the foam. One unique advantage of the technique is the lack of interactions between the foam and container surfaces, which must be accounted for in other techniques. Results are presented......
详情请见文章内容。[详细]
The technique of acoustic levitation normally produces a standing wave and the potential well of the sound field can be used to trap small objects. Since no solid surfaces is involved it has been widely applied for the study of fluid physics, nucleation, bio/chemical processes, and various forms of soft matter. In this article, we survey the works on drop dynamics in acoustic levitation, focus on......[详细]
The contactless coalescence of a droplet is of paramount importance for physical and
industrial applications. This paper describes a coalescence method to be used mid-air via acoustic levitation using an ultrasonic phased array system. Acoustic levitation using ultrasonic phased arrays provides promising lab-on-a-drop applications, such as transportation, coalescence, mixing, separation, evaporation, and extraction in a continuous operation. 详情请见文章内容[详细]
The surface tensions of graphene oxide nanofluids of five mass concentrations were measured by the oscillation droplet method in an acoustic levitator. The oscillation information of the suspension droplets was obtained by combining acoustic with image recognition technology, and a shape correction coefficient a was introduced to modify the Rayleigh equation. Over the temperature ranging from −7 to 10°C......[详细]
Ultrasonic levitation of some small living animals such as ant, ladybug, and young fish has been achieved with a single-axis acoustic levitator. The vitality of ant and ladybug is not evidently influenced during the acoustic levitation, whereas that of the young fish is reduced because of the inadequacy of water supply. Numerical analysis shows that the sound pressures on the ladybug’s surface almost reach the incident pressure amplitude p0 due to sound scattering.
详情请见文章内容。[详细]
This paper deals with the thermo-physical changes that a droplet undergoes when it is radiatively heated in a levitated environment. The heat and mass transport model has been developed along with chemical kinetics within a cerium nitrate droplet. The chemical transformation of cerium nitrate to ceria during the process is predicted using Kramers’ reaction mechanism which justifies the formation of ceria at a very low temperature as observed in experiments.
详情请见文章。[详细]
参与评论
登录后参与评论