常壓射頻電容耦合式電漿束熱流場分析

Abstract

大氣電漿束(Atmospheric Pressure Plasma Jet, APPJ)已經發展了很長一段時間了，在許多方面都有廣泛的應用,表面改質技術，表面清潔技術，生醫及顯示器等等，多數的實驗研究以研究電性為主，在以往的研究裡對於流場分析是屬於少數。 本實驗主要研究大氣電漿束的流場以及溫度場結構， 實驗控制參數：氣體流量,為10、15、20slm，射頻功率源為80、120、150W，使用氣體為Ar，以Particle Image Velocimetry (PIV)量測同軸大氣電漿束出口處的2D 速度分佈，Thermocouple (TC)量測出口處的溫度分佈，Optical Emission Spectroscopy (OES)量測出口處的自由基分佈，實驗內容分為三個個部分：(一)對大氣電漿束出口處於電漿點起前後量測速度分佈， (二)電漿於不同流量及不同輸入功率下速度及溫度分佈的變化， (三)以光譜儀量測沿著出口距離自由基的變化及使用VI-probe 驗證在追蹤粒子導入前後的電性差異。我們觀察到的結果在同樣流量下隨著輸入功率的增加, 對整體速度分佈的變化不大, 溫度分佈隨著流量的增加而降低, 而光譜儀在出口處0~4mm 的範圍量測到大量的氧自由基, 以及在追蹤粒子的導入前後會造成電漿內部電性的差異。

APPJs have found applications in surface modification, surface cleaning, sterilization, thin-film deposition and etching, to name a few. Most experimental studies empasized on the electrical properties such as the power deposition and I-V curve. Measurements of flow field are not seen in the literature, which is otherwise very important from the viewpoint of applications. This study aims to understand the structure of flow and thermal field which issues from a coaxial atmospheric-pressure plasma jet (APPJ). The control parameters of the experiment: Ar gas flow rate, 10,15,20 slm, RF power source for 80,120,150 W, We get the velocity distribution by using the particle image velocimetry (PIV), get the temperature distribution by using the thermocouple (TC), and get the radicals intensity distribution by using the Optical Emission Spectroscopy (OES). Experiment content is divided into three parts. The first part is to get the velocity distribution of the exit from the jet with and without plasma. The second part is to measure the temperature distribution of the exit from the jet at different flow rates and different input power. The final part is to measure the intensity of radicals along the exit from the jet and use V-I probe to measure the electrical property with and without seeding particles. The distribution of velocity increased slightly with the input power. As the gas flow rate increased, the temperature of coaxial flow issuing from the jet would be deceased. But the change is not clearly. OES measurement from the experimental results can be known that the plasma can generate a lot of oxygen radicals at 0~4mm from the jet. V-I probe measurement from the experimental results can be know that the electrical properties with seeding and without seeding are different.