【摘要】：超聲振動珩磨技術是一種難加工材料的有效處理方法,磨削液在超聲作用下會產生空化現象�？栈莸恼駝舆^程、潰滅瞬間的高溫高壓物理環(huán)境以及隨之產生的微射流和沖擊波都會對材料表面產生不可忽略的影響。本論文針對磨削區(qū)的單空化泡,結合空化泡動力學相關理論,采用理論建模、數值仿真和試驗分析等方式,研究了單空化泡運動過程中各參量的變化情況,并探究了多種因素對單空化泡運動的影響。主要的研究內容和結論如下:1.在前人研究基礎上,考慮煤油蒸氣的冷凝與蒸發(fā)和珩磨加工環(huán)境的特點,建立了超聲振動珩磨磨削區(qū)單空化泡的動力學模型,運用Matlab軟件對空化泡運動過程中的氣泡半徑、泡內溫度、泡內壓強和煤油蒸氣分子數進行了數值模擬,結果表明煤油蒸氣的冷凝與蒸發(fā)能夠有助于解釋泡內溫度和泡內壓強的變化過程。2.通過比較傳統超聲與超聲振動珩磨兩種環(huán)境、不同初始半徑下磨削區(qū)空化泡狀態(tài)參量的變化情況,發(fā)現由于珩磨壓力的存在,超聲振動珩磨下的空化泡運動幅值受到較大抑制,但運動變化頻率卻加快,泡內壓強與溫度的最小值較大,同時泡內煤油蒸氣分子數較少;隨著空化泡初始半徑的增大,氣泡半徑快速膨脹的時刻提前,最大膨脹倍數減小,壓縮潰滅時間也相應縮短,泡內壓力和溫度的最大值變大,泡內煤油蒸氣分子數增多。3.研究超聲珩磨和外界環(huán)境因素對空化泡運動過程的作用,結果表明珩磨壓力、煤油液粘性和超聲頻率有較大影響,而珩磨頭的回轉和往復速度幾乎沒有影響。珩磨壓力的增大會顯著減小空化泡的最大半徑,還可能將空化泡直接壓潰;煤油粘性系數越大,空化泡膨脹的阻力越大,半徑的變化越小;超聲波頻率越高,超聲作用時間越短,空化泡越難以充分生長,半徑將變小。4.探討不同外界聲場激勵下空化泡的運動狀態(tài),與單頻激勵(正弦信號)相比,發(fā)現多頻激勵下的空化泡會經歷更為平緩的生長過程,半徑變大;不同的多頻激勵相位差組合,會隨機地改變空化泡的運動過程;三角波的功率較小,輸入的聲場能量也較少,致使空化泡半徑略小,而方波正好與三角波相反。5.采用水聽器法測量了超聲珩磨磨削區(qū)的空化聲場,結果表明隨著水聽器探頭與變幅桿距離的不斷增大,測得的空化聲壓值逐漸減小;增大超聲波發(fā)生器的功率,聲壓值明顯升高。利用鋁箔腐蝕法研究了空化效應對材料表面的空蝕作用,鋁箔表面會出現許多大小不一的空蝕坑;增大功率,減小鋁箔與變幅桿的橫向距離,空蝕坑變密集,聲壓值越大的地方,空化效應越劇烈。
[Abstract]:Ultrasonic vibration honing is an effective method for the treatment of refractory materials. The grinding fluid can produce cavitation under the action of ultrasonic. The vibration process of cavitation bubble, the instantaneous physical environment of high temperature and high pressure, and the resulting micro-jet and shock wave can not be ignored. Based on the theory of cavitation dynamics and theoretical modeling, numerical simulation and experimental analysis, the variation of parameters in the process of single cavitation bubble is studied in this paper. The influence of various factors on the motion of cavitation bubble is also discussed. The main contents and conclusions are as follows: 1. On the basis of previous studies, considering the characteristics of condensing, evaporation and honing environment of kerosene vapor, a dynamic model of single cavitation bubble in ultrasonic vibration honing grinding area is established. The bubble radius in the process of cavitation bubble motion is calculated by using Matlab software. The results show that condensation and evaporation of kerosene vapor can help to explain the change process of temperature and pressure in the bubble. By comparing the variation of cavitation bubble state parameters in different initial radius between traditional ultrasonic honing environment and ultrasonic vibration honing environment, it is found that the amplitude of cavitation bubble motion under ultrasonic vibration honing is greatly restrained due to the existence of honing pressure. However, with the increase of the initial radius of the cavitation bubble, the rapid expansion of the bubble radius is advanced, and the maximum expansion multiple decreases, with the increase of the initial radius of the cavitation bubble, the minimum value of the pressure and temperature in the bubble is larger, and the number of kerosene vapor molecules in the bubble is less. The compression collapse time was also shortened, the maximum pressure and temperature in the bubble increased, and the molecular number of kerosene vapor in the bubble increased by .3. The effects of ultrasonic honing and external environmental factors on cavitation bubble movement are studied. The results show that honing pressure, kerosene viscosity and ultrasonic frequency are greatly affected, while the rotary and reciprocating velocity of honing head have little effect. As the honing pressure increases, the maximum radius of cavitation bubble will be significantly reduced, and the cavitation bubble may be crushed directly. The larger the viscosity coefficient of kerosene, the greater the resistance of cavitation bubble expansion, the smaller the change of radius, and the higher the ultrasonic frequency. The shorter the ultrasonic action time, the more difficult the cavitation bubble is to grow fully, and the radius will become smaller. 4. The moving state of cavitation bubble under different external acoustic field excitation is discussed. Compared with single frequency excitation (sinusoidal signal), it is found that the cavitation bubble under multi-frequency excitation will experience a more smooth growth process and a larger radius, and different combinations of multi-frequency excitation phase difference, The moving process of cavitation bubble will be changed randomly, the power of triangle wave is smaller and the input energy of sound field is less, so the radius of cavitation bubble is slightly smaller, and the square wave is just opposite to triangle wave. The cavitation sound field in the grinding area of ultrasonic honing is measured by hydrophone method. The results show that with the increasing of the distance between the hydrophone probe and the horn, the measured sound pressure decreases gradually, and the power of the ultrasonic generator increases. The sound pressure increased obviously. The cavitation effect of the cavitation effect on the surface of the material is studied by using the aluminum foil corrosion method. Many cavitation pits of different sizes will appear on the surface of the aluminum foil, increasing the power, reducing the transverse distance between the aluminum foil and the amplitude lever, and the cavitation pit becoming denser. The greater the sound pressure, the more intense the cavitation effect is.
【學位授予單位】：中北大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TG663;TG580.67

【參考文獻】

相關期刊論文 前10條

1 王潞杰;祝錫晶;王建青;;考慮煤油蒸汽冷凝與蒸發(fā)的超聲珩磨區(qū)空化特性研究[J];中北大學學報(自然科學版);2017年02期

2 張鵬利;林書玉;喬輝;孟泉水;;聲場中雙空化泡的運動特性[J];應用聲學;2017年02期

3 王潞杰;祝錫晶;王建青;吳書安;;超聲珩磨區(qū)考慮煤油蒸氣冷凝與蒸發(fā)的空化泡動力學分析[J];科學技術與工程;2017年01期

4 王成會;莫潤陽;胡靜;;低頻超聲空化場中柱狀泡群內氣泡的聲響應[J];物理學報;2016年14期

5 楊日福;張凡;耿琳琳;;雙頻超聲空化氣泡動力學影響因素分析[J];計算機與應用化學;2016年06期

6 郭璇;楊艷玲;李星;周志偉;冀思揚;韓星航;王帥;曾慶品;張浩;;基于Matlab的超聲空化場測量與可視化分析[J];中國環(huán)境科學;2016年03期

7 張小強;祝錫晶;王建青;;超聲振動珩磨單空化泡潰滅溫度研究[J];中國機械工程;2016年06期

8 郭策;祝錫晶;王建青;葉林征;;超聲場下剛性界面附近潰滅空化氣泡的速度分析[J];物理學報;2016年04期

9 沈陽;朱彤;由美雁;糜彬;韓進;謝元華;李現瑾;Kyuichi Yasui;;考慮水蒸汽蒸發(fā)和冷凝的超聲空化特性研究[J];高校化學工程學報;2015年04期

10 王香君;高鈞;楊義新;尤暉;;基于單光子探測的超聲空化強度測量方法[J];儀表技術;2015年06期

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