在過去的幾十年，微波電漿火炬成為了受歡迎的電漿源之一，因為它有結構簡單、在不同的工作環境有高度的彈性，而且不需要電極就能操作。微波電漿火炬可以廣泛運用在多種應用上，例如二氧化碳的分解、製氫、氣化以及汙染物的處理等等。有高的能量耦合效率的微波電漿火炬是需要的，因此如何控制微波電漿火炬的效能，使其能量反射較小，是需要被設計的。本研究主旨為建立微波電漿源之數值模擬模型，模型包含電漿理論、電磁波理論以及流場與熱傳理論，透過探討微波電漿的操作條件與電漿隨參數之變化，掌握微波電漿的基本特性，並且依據所建立之基本微波電漿數值模擬模型設計出高能量耦合效率的結構。
為符合實務上的需求，設計一個波導管的結構，將微波從腔體上方送入，並且固定輸入的微波功率，以符合實際應用。先以符合表面波模態的微波頻率激發初步電漿分布，再調整微波功率源的頻率至共振頻率，藉以提高微波吸收功率，其穩態結果之微波特性及電漿特性與固定吸收功率之結果相近。

Over the past several decades, microwave plasma torches have become one of the most popular plasma sources because of their advantages of simple structure, high flexibility in different working environments, and electrodeless working ability. Microwave plasma torches were found to have great potential in a wide range of applications, for example, carbon dioxide dissociation, hydrogen production, gasification, waste diposal, and so on. High power coupling efficiency of microwave plasma torch is necessary, how to control the efficiency of microwave plasma torch to minimum the power reflection needs to be design. The objective of this work is building a numerical simulation model of surface wave plasma, model including the plasma theory, electromagnetic wave theory, as well as gas flow and heating transfer theory. Realizing the features of surface wave plasma by analyzing the simulation. Next, design a microwave plasma torch requiring high power coupling efficiency.
In order to meet the practical needs, a structure of a waveguide is designed to deliver microwaves from above of the cavity, and the input microwave power is fixed to meet the practical application. First, the initial plasma distribution is excited by the microwave frequency that conforms to the surface wave mode, and then the frequency of the microwave power source is adjusted to the resonant frequency, so as to increase the microwave absorption power. The simulation result is similar to fixed absorbed power.

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