بررسي شرايط عملكردي بر رفتار حركتي ذره و حداكثر چگالي قابل تعليق در فرآيند تعليق فراصوت

Investigation of Operational Parameters on the Motional Behavior and Maximum Particle Levitated Density in Ultrasonic Levitation

ﺗﻌﻠﯿﻖ ﻓﺮاﺻﻮت ﺑﻪ دﻟﯿﻞ ﻋﺪم واﺑﺴﺘﮕﯽ ﺑﻪ ﺟﻨﺲ ﻣﺎده، ﭘﺘﺎﻧﺴﯿﻞ ﺑﺎﻻﯾﯽ ﺑﺮاي اﺳﺘﻔﺎده در ﮐﺎرﺑﺮدﻫﺎي ﻣﺨﺘﻠﻒ دارد. از ﻣﯿﺎن ﭘﺎراﻣﺘﺮﻫﺎي ﻣﻮﺛﺮ، ﻓﺎﺻﻠﻪ ﺑﺎزﺗﺎﺑﻨﺪه ﺗﺎ ﻣﺒﺪل و وﻟﺘﺎژ ﻧﻘﺶ ﻣﻮﺛﺮﺗﺮي در اﯾﻦ ﻓﺮآﯾﻨﺪ اﯾﻔﺎ ﻣﯽﮐﻨﻨﺪ. اراﺋﻪ ﯾﮏ ﻣﺪل ﻋﺪدي دﻗﯿﻖ، ﻧﻘﺶ ﻣﻮﺛﺮي در ﻣﻄﺎﻟﻌﻪ ﮐﺎراي ﭘﺎراﻣﺘﺮﻫﺎ دارد. دراﯾﻦ ﻣﻘﺎﻟﻪ، ﯾﮏ ﻣﺪل ﻋﺪدي دﻗﯿﻖ ﺑﺮاي ﺑﺮرﺳﯽ اﺛﺮات ﻣﻮﺛﺮ در ﻓﺮآﯾﻨﺪ اراﺋﻪ ﺷﺪ. در ﻣﺪل اراﺋﻪ ﺷﺪه، ﺑﺎ ﺣﻞ ﻫﻤﺰﻣﺎن ﻣﻌﺎدﻻت ﺣﺎﮐﻢ ﺑﺮ ﭘﯿﺰواﻟﮑﺘﺮﯾﮏ، ﻣﻌﺎدﻟﻪ ﻣﻮج در ﻣﺤﯿﻂ ﺟﺎﻣﺪ و ﺳﯿﺎل و ﻧﯿﺰ در ﻧﻈﺮ ﮔﺮﻓﺘﻦ ﺷﺮاﯾﻂ ﺳﻪ ﺑﻌﺪي ﺗﻌﻠﯿﻖ ﺳﻌﯽ ﺷﺪه ﺷﺮاﯾﻂ ﺷﺒﯿﻪﺳﺎزي ﻣﺸﺎﺑﻪ ﺣﺎﻟﺖ ﺗﺠﺮﺑﯽ ﺑﺎﺷﺪ. ﺗﻄﺎﺑﻖ ﻣﻨﺎﺳﺐ ﻧﺘﺎﯾﺞ ﻣﺪل و ﻧﺘﺎﯾﺞ ﺗﺠﺮﺑﯽ ﺑﻪ ﻫﻤﯿﻦ دﻟﯿﻞ اﺳﺖ. ﺑﺎ اﺳﺘﻔﺎده از ﻣﺪل ﻋﺪدي، اﺛﺮ وﻟﺘﺎژ و ﻓﺎﺻﻠﻪ ﺑﯿﻦ ﻣﺒﺪل و ﺑﺎزﺗﺎﺑﻨﺪه ﺑﺮ ﺗﻌﻠﯿﻖ ذرات ﺑﺮرﺳﯽ ﺷﺪ. ﺣﺮﮐﺖ ذره ﺣﯿﻦ ﺗﻌﻠﯿﻖ، ﺑﺎ اﺳﺘﻔﺎده از ﭘﺎراﻣﺘﺮﻫﺎي ﭘﯿﺸﻨﻬﺎد ﺷﺪه ﻣﺸﺨﺼﯽ در اﯾﻦ ﻣﻘﺎﻟﻪ ﺗﻮﺻﯿﻒ ﺷﺪ. ﺗﻌﺮﯾﻒ ﭘﺎراﻣﺘﺮﻫﺎي ﻓﻮق، اﻣﮑﺎن ﻣﻘﺎﯾﺴﻪ ﺷﺮاﯾﻂ ذره ﻣﻌﻠﻖ در ﺷﺮاﯾﻂ ﮐﺎري ﻣﺨﺘﻠﻒ را اﯾﺠﺎد ﻣﯽ ﮐﻨﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﺑﺮاي ﺗﻌﻠﯿﻖ ﻣ ﺎﺳﺐ ذرات، ﺗﻨﻈﯿﻢ ﭘﺎراﻣﺘﺮﻫﺎي ذﮐﺮ ﺷﺪه ﺑﺎﯾﺪ ﺑﺮ اﺳﺎس ﻣﻘﺎدﯾﺮ ﯾﮑﺪﯾﮕﺮ اﻧﺠﺎم ﺷﻮد؛ ﻫﻤﭽﻨﯿﻦ ﺑﺎ ﻣﺪل ﻋﺪدي اراﺋﻪ ﺷﺪه ، ﺣﺪاﮐﺜﺮ ﭼﮕﺎﻟﯽ ﻗﺎﺑﻞ ﺗﻌﻠﯿﻖ در ﺷﺮاﯾﻂ ﮐﺎري ﻣﺨﺘﻠﻒ ﺑﺎ دﻗﺖ 0/45 درﺻﺪ اراﺋﻪ ﺷﺪ.

Ultrasonic levitation has a high potential to be used in different applications due to its independence from the material. Among effective parameters, the distance between the reflector and the transducer and applied voltage plays an important role in the process. Presenting a precise numerical model would be helpful. In this paper, a precise numerical model was presented to study of the process. In the model, by simultaneous solving the equations of the piezoelectric and the wave equations in the solid and fluid medium as well as considering the three-dimensional levitation, the simulation conditions were similar to the experiments. Hence results agreed well with the experimental results. The effect of voltage and distance between the transducer and the reflector on the levitated particle was investigated using the model. Particle motion during levitation was explained using the proposed certain parameters. Defining the parameters makes it possible to compare the particle conditions at different working status. The results showed that to properly levitated object conditions, the adjustment of the parameters should be made based on each other's values. Moreover, the maximum density in different working conditions with an accuracy of 0.45% was predicted using the numerical model.