| With the development of studies, such as industrial materials, biochemical analysis,experimental investigation of free drops and so on, experimental environment is requiredhigher and higher. Containerless processing technique can provide a good experimentalenvironment for these studies. Among the numerous techniques which can provide thecontainerless effect on ground conditions, ultrasonic standing wave levitation has beenfavored and it’s application industries and application areas are gradually expanded, for it’sgood suspension stability, no requirement of the material of the suspended objects and noadditional effect on the suspended objects.From the invention of the frist ultrasonic standing wave levitation device to the present,various methods have been attempted to improve the performance of the ultrasonic standingwave levitation device, and applying a resonance tube on the ultrasonic standing wavelevitation device is included. But till now, the influencing characteristics of resonance tubeon the performance of ultrasonic standing wave levitation is just been applied and has notbeen analyzed and studied. In view of this, the influencing characteristics of resonance tubeon the performance of ultrasonic standing wave levitation will be taken as the researchobject in this paper. Simulation analysis and experimental study of the influencingcharacteristics of resonance tube on the performance of ultrasonic standing wave levitationare carried out, so that people can choose the the right resonance tube in different situationsfor the purpose of enhancing the the performance of ultrasonic standing wave levitation.The design method of the piezoelectric transducer structure and parameters are given inthis paper, and the relationship between the emitter parameters and the ultrasonicwavelength is established, for the considering that the ultrasonic wave produced by thepiezoelectric transducer should has a larger radiation area. And on the basis of this, thestructure and parameters of the emitter is designed. Modal analysis of the combination ofpiezoelectric transducer and emitter is carried out by the Ansys software, and the modalanalysis result showed that the natural frequency of the combination of piezoelectrictransducer and emitter is19330Hz and the maximum displacement occurs at the edge of thetransmitter. The piezoelectric transducer is able to meet the requirements in the frequency and the displacement and the prototype of piezoelectric transducer is produced According tothe design method.Based on the piezoelectric transducer designed in this paper, the finite element modelof ultrasonic standing wave levitation device is build, and the comparative simulationanalysis of the influencing characteristics of resonance tube on the sound pressure indifferent types of ultrasonic standing wave levitation device is carried out. Then thedistribution of relative time average potential distribution and relative force of the levitationis obtained. After completing the above analysis, it is found that resonance tube could havesome impact on the levitation force and suspension stability, and the impact is moresignificant when the surface of the reflector is concave spherical.Experimental study of the resonance tube on the ultrasonic standing wave levitationforce and suspension stability is carried out using the ultrasonic standing wave levitationtesting system build in this paper. The experimental results are basically the same with thesimulation results.In summary, the influencing characteristics of the resonance tube on the ultrasonicstanding wave levitation is reasearched in both simulation analysis and experimental studyin this paper. The conclusion came that suitable dimensions of the resonance tube caneffectively improve the performance of the ultrasonic standing wave levitation, and themagnitude of the improvement is greater when the surface of the reflector is concavespherical. |
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