Effect of the Acoustic Field Geometric Parameters on Planar Array Acoustic Levitator

Author(s):  
Huijuan Dong ◽  
Peng Zhang ◽  
Panagiotis Papouris

Acoustic contactless manipulation technique that is capable of transporting and manipulating of small particles is highly attractive in studying of many physical phenomena and biochemical processes. The finite element method is used to study the effect of the acoustic field geometric parameters on the acoustic levitator consisting of the transducer planar array and a reflector. The optimal acoustic chamber height and the distances between the array elements are determined through the numerical simulation. The analytical results provide the geometry parameters that can be used in optimizing acoustic chamber for particles transportation.

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Qingtao Gong ◽  
Zhanyang Chen ◽  
Hongbin Gui ◽  
Dong Yu

The underwater acoustic radiation of the submarine power cabin has recently become a hot topic in the industry and also in the academia. In this article, the vibration and underwater acoustic radiation of a ring-stiffened conical shell with bases are investigated numerically by means of the combination of the finite element method and boundary element method. The acoustic radiation field is obtained by the traditional acoustic field model and ISO acoustic field model, respectively. A series of numerical examples are given, and the results are compared. Besides, the sound pressure at different positions with frequency is further studied. It is shown that the sound radiated by the structure mainly propagates to the side directions of the shell and propagates relatively less to the front side and the rear side.


2011 ◽  
Vol 199-200 ◽  
pp. 749-753
Author(s):  
Xiao Bo Zuo ◽  
Jian Min Wang ◽  
Chao Liang Guan ◽  
Juan Li

The static performance of an aerostatic bearing with angled surface self-slot-compensation is analyzed. The consistent condition was applied to unitize the Reynolds equation of different forms and the finite element method (FEM) was used to solve the equation. The load carrying capacity (LCC) and the stiffness of the bearing was obtained and the influence of the geometric parameters was discussed. It is concluded that this self-compensating aerostatic bearing can achieve a good performance; the geometric parameters of the gap are interactive, and should be rationally matched.


Author(s):  
Michael W. Sracic ◽  
Jordan D. Petrie ◽  
Henry A. Moroder ◽  
Ryan T. Koniecko ◽  
Andrew R. Abramczyk ◽  
...  

Acoustic levitation is an advantageous particle positioning mechanism currently employed for applications of x-ray spectroscopy and micro-material manufacturing[1], [2]. By levitating a particle using only acoustic pressure waves, one eliminates the need for a container or other physical structure which may contaminate the specimen. Unfortunately, the pressure field generated by a standing acoustic wave is susceptible to periodic instabilities, and a particle that is levitated in this field tends to vibrate. The amplitude of the vibration is largest in the directions that are orthogonal to the axis in which the acoustic wave is generated. Therefore, by generating additional acoustic waves in each orthogonal axis, the vibration amplitude of the levitated particle is significantly reduced. The authors have shown this phenomenon to be true in a previous study[3]. In this paper, the authors explore the details of the pressure field that is generated with the device. A single degree-of-freedom relationship is developed between the acoustic field pressure, the location of the levitated particle, and the mechanical vibration needed to produce levitation. In order to levitate a 100 micrometer diameter water droplet at 55 kilohertz, the calculations suggest that the transducer must achieve an average surface vibration amplitude of at least 6.43 micrometers. This mechanical vibration must produce a root means-squared pressure amplitude of 933 Pascal. Under these conditions, the particle will levitate approximately 0.4 millimeters below a zero pressure node. To validate the use of the single degree of freedom relationships and to explore the acoustic field for one, two, and three-axis levitation, the authors designed and prototyped an acoustic levitator capable of generating standing waves in three orthogonal directions. Using a simple electrical control circuit, the acoustic wave transducers of each axis can be turned on individually or simultaneously. An experiment was developed to measure the pressure of the acoustic field using a microphone. Preliminary pressure magnitude results were measured for one-axis levitation along the center of the vertical axis of the levitator. The measurements suggest that the theoretical development provides a valid first approximation for the pressure magnitude and required mechanical vibration amplitude.


2011 ◽  
Vol 490 ◽  
pp. 312-322
Author(s):  
Henryk G. Sabiniak ◽  
Robert Cichowicz

A dynamic development of numerical methods enables even so complicated geometrical modelling as modelling of hypoidal teeth, and in particular of worm teeth. Building on the basis of the finite element method of this type of geometrical mathematical model enables observing and analysing physical phenomena taking place in the teeth, e.g. changes of pressure distribution along the contact lines depending on the phase of meshing for particular cooperating pairs of teeth. Due to limited technical possibilities and mathematical apparatus such analyses were carried out only on the basis of the theory of plates with constant thickness. An unquestionable advantage of such numerical modelling is a short time needed to obtain final results, which enables profound analysis of the transmitted load. The knowledge of course of pressure distribution along the contact lines of particular pairs of intermeshing teeth in worm gears already in the design phase enables taking into consideration in adequate correction or even modification of the working surface of teeth, with the aim to equalise the distribution of pressure.


2019 ◽  
Vol 216 ◽  
pp. 03005
Author(s):  
Michele Riva ◽  
Elia A. Vallicelli ◽  
Andrea Baschirotto ◽  
Marcello De Matteis

Proton range verification by ionoacoustic wave sensing is a technique under development for applications in adron therapy as an alternative to nuclear imaging. It provides an acoustic imaging of the proton energy deposition vs. depth using the acoustic wave Time of Flight (ToF). State-of-the-art (based on simulations and experimental results) points out that this detection technique achieves better spatial resolution (< 1 mm) of the proton range comparing with Positron-Emission-Tomography (PET) and prompt gamma ray techniques. This work presents a complete Geant4/k-Wave model that allows to understand several physical phenomena and to evaluate the key parameters that affect the acoustic field generated by the incident proton radiation.


2013 ◽  
Vol 441 ◽  
pp. 470-475
Author(s):  
De Xin Zhou ◽  
Xue Qian Tang ◽  
Xiang Lin Zhan

A numerical simulation model based on the finite element method (FEM) and wave analysis is proposed to study the acoustic field of a linear instructions and ultrasonic phased array (LUPA) transducer. The ultrasonic wave propagation in the isotropic solid is studied. The delay law controlling for electronic scanning of a LUPA transducer is analyzed. The ultrasonic wave propagation in the inspection material can be visualized in the form of displacement cloud images by FEM modeling. Experiments show that the model can efficiently and accurately predict the radiation field of beam focusing, steering and electronic scanning of a linear phased array transducer. By employing the proposed method, parameters can be conveniently changed to study the acoustic field of the ultrasonic beam in the medium. It is very helpful for designing and applying the linear phased array transducer and flaw inspection in NDT field.


2014 ◽  
Vol 599-601 ◽  
pp. 1539-1543
Author(s):  
Hai Bo Wan ◽  
Shi Jian Zhu ◽  
Qi Wei He ◽  
Shao Chun Ding

To localize and identify the noise sources of the AUV, the cylindrical NAH method was proposed. The feasibility was verified by the acoustic field simulation, the influence of the array test distance, holographic planar array position errors and the reconstruction phase errors on the accuracy of the sound field reconstruction was analyzed, which would provide some references for the engineering applications.


2020 ◽  
pp. 9-22
Author(s):  
V.L. Kiselev ◽  
A. S. Pronin

Using the finite element method and CAD SolidWorks Simulation, the relationship between the geometric parameters of workpieces and the error in processing flat surfaces of levers caused by elastic deformations of the workpiece due to the application of holding force is established. In this paper, we developed a method for determining the error of processing flat surfaces that occurs from fixing, compiled a model for determining the error by the finite element method, and calculated the error of processing flat surfaces that occurs from fixing for workpieces with different geometric parameters. As a result of the study, the relationship between the value of the center distance of workpieces and the error in processing flat surfaces of levers caused by elastic deformations of the workpiece due to the application of holding forces was determined.


2013 ◽  
Vol 433-435 ◽  
pp. 193-196
Author(s):  
Chuan Liang Shen ◽  
Ye Han ◽  
Xue Wei Song ◽  
Da Xue Wang

The finite element method is adopted to simulate the vibration control effectiveness of autobody thin-walled structure by using the piezoelectric patches. The geometric parameters of thickness and area are chosen as the influence factors to analyze the control effectiveness of piezoelectric vibration control system. The simulation results show that the base metal thickness, piezoelectric patch thickness and the area of piezoelectric patch are main parameters and influence the control effectiveness obviously. The influence rules of these geometric parameters are obtained.


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