Calculation of the radiation force on a cylinder in a standing wave acoustic field

2005 ◽  
Vol 38 (15) ◽  
pp. 3279-3285 ◽  
Author(s):  
David Haydock
Keyword(s):  
Standing Wave ◽  
Acoustic Field ◽  
Radiation Force

scholarly journals Mathematical modeling and experimental study on solid–liquid suspension separation in ultrasonic standing wave field

2021 ◽  
pp. 146134842110229
Author(s):  
Yajing Wang ◽  
Liqun Wu ◽  
Yaxing Wang ◽  
Yafei Fan
Keyword(s):  
Standing Wave ◽  
Sound Pressure ◽  
Acoustic Radiation ◽  
Sound Field ◽  
Radiation Force ◽  
High Energy ◽  
Factors Affecting ◽  
Liquid Suspension ◽  
Ultrasonic Standing Wave ◽  
Solid Liquid

A new method of removing waste chips is proposed by focusing on the key factors affecting the processing quality and efficiency of high energy beams. Firstly, a mathematical model has been established to provide the theoretical basis for the separation of solid–liquid suspension under ultrasonic standing wave. Secondly, the distribution of sound field with and without droplet has been simulated. Thirdly, the deformation and movement of droplets are simulated and tested. It is found that the sound pressure around the droplet is greater than the sound pressure in the droplet, which can promote the separation of droplets and provide theoretical support for the ultrasonic suspension separation of droplet; under the interaction of acoustic radiation force, surface tension, adhesion, and static pressure, the droplet is deformed so that the gas fluid around the droplet is concentrated in the center to achieve droplet separation, and the droplet just as a flat ball with a central sag is stably suspended in the acoustic wave node.

Performance study of standing wave levitation with emitting and reflecting surface of concave sphere structure

2013 ◽  
Vol 227 (11) ◽  
pp. 2504-2516 ◽  
Author(s):  
Xiaoyang Jiao ◽  
Guojun Liu ◽  
Jianfang Liu ◽  
Xiaolun Liu
Keyword(s):  
Standing Wave ◽  
Spherical Surface ◽  
Radiation Force ◽  
Structural Parameter ◽  
Matlab Simulation ◽  
Performance Study ◽  
Ansys Software ◽  
Ultrasonic Standing Wave ◽  
Steel Balls ◽  
Reflecting Surface

In order to improve levitation capability and stability of ultrasonic standing wave, a novel levitation device was presented, which adopted concave spherical surface on the emitter and the reflector. Using ANSYS software, the acoustic field generated by the concave spherical emitting surface was analyzed and the formation of ultrasonic standing wave was simulated. Based on the simulation result, the distribution and maximum acoustic pressure under different radius of concave spherical surface on the emitter and the reflector were ascertained. Through the MATLAB simulation, the optimal structural parameter and levitation position were predicted. Based on the optimization result, the prototype of standing wave levitation device was designed and manufactured. In the laboratory, the radiation force was tested and levitation experiments were also carried out and the actual levitation position was in accordance with the simulation results. When the distance between the emitter and the reflector equaled to about 34.9 mm, three steel balls of 3 mm diameter could be levitated at the same time in three disparate nodes position, the levitation capability and stability were demonstrated to be enhanced largely.

CALCULATION OF ACOUSTIC RADIATION FORCE AND MOMENT IN MICROFLUIDIC DEVICES

2014 ◽  
Vol 34 ◽  
pp. 1460380 ◽  
Author(s):  
KIAN-MENG LIM ◽  
SHAHROKH SEPEHRI RAHNAMA
Keyword(s):  
Numerical Methods ◽  
Acoustic Field ◽  
Acoustic Radiation ◽  
Microfluidic Devices ◽  
Radiation Force ◽  
Acoustic Radiation Force ◽  
Operating Conditions ◽  
Surface Integral ◽  
Analytical Results ◽  
Multipole Expansion Method

The ability to compute the acoustic radiation force and torque acting on a particle is critical to the design of microfluidic devices and the operating conditions for separation of different species of particles or biological cells using this force field. Closed-form formulae had been reported in the literature for calculating the acoustic radiation force acting on simple geometries such as spheres and ellipsoids. Also, these analytical formulae are limited to objects that are small compared to the wavelength of sound in the surrounding fluid. Numerical methods provide a more flexible way to calculate the acoustic radiation force and torque on suspended objects of arbitrary shape and size. In this paper, we will present results of using the finite element method and the multipole expansion method to calculate the acoustic radiation force and moment. For harmonic excitation, the Helmholtz equation is solved for the velocity potential of the acoustic field with the appropriate boundary conditions imposed on the surface of the spherical or ellipsoidal objects. The resultant force and torque were then calculated by performing a surface integral of the second order, time-averaged Brillouin stress over the object. The numerical results show good agreement with the analytical results for small size spheres and ellipsoids. When the object size is comparable to the wavelength of the acoustic field, the analytical results breakdown and numerical methods are necessary to obtain accurate results.

scholarly journals Unsteady particle motion in an acoustic standing wave field

2019 ◽  
Author(s):  
S. Wanga ◽  
J. S. Allen ◽  
A. M. Ardekani
Keyword(s):  
Wave Field ◽  
Standing Wave ◽  
Particle Motion ◽  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Particle Interaction ◽  
Inertial Force ◽  
Radiation Force ◽  
Acoustic Standing Wave ◽  
Standing Wave Field

The acoustic-based separation has attracted considerable attention in biomedical research, such as sorting of cells and particles. Current design principles used for acoustic systems are based on the steady Stokes theory, equating the Stokes drag with the primary radiation force. However, this approach is not valid for large cells/particles or in the presence of particle–particle interaction. In this work,we analytically examine unsteady inertial affects and particle–particle hydrodynamic interaction on the particle motion in a viscous fluid in the presence of an acoustic standing wave field. Comparing our results to the steady Stokes theory, we find that the unsteady inertial force decreases the particle’s velocity, while particle–particle interaction enhances it. For a particular acoustic-based separation approach ‘tilted-angle standing surface acoustic waves (taSSAW)’, we find that both effects of unsteady inertial force and particle–particle interaction are evident and should be considered for O(10μm) particles or larger. Our study improves the current predictions of particle trajectory in acoustic-based separation devices.

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