本研究的主要目的是利用計算流體動力學（CFD）技術對牙科氣動手機在空轉運作時的流場進行模擬，並深入探討在不同條件下對壓力分布、扭矩特性及噪音影響的氣動聲學特性。研究首先對牙科氣動手機進行物理建模，並設定相應的模擬初始條件。而本次研究困難之處在於需要對流場進行深度分析，網格需要非常細小，以準確捕捉其內部流場的動態變化，需要極為大量的計算資源，因此通過超級電腦進行平行化運算已達成計算需求。並且通過數值模擬，本次研究分析了牙科氣動渦輪手機在高速旋轉時產生的壓力波動，並利用快速傅立葉變換（FFT）研究了壓力波動的頻率特性。此外，本研究評估了葉輪設計變化對扭矩和流場特性的影響。最終，通過比較不同葉輪設計的模擬結果，探討了形狀優化的可能性，期望在未來能透過改變葉輪形狀來降低操作噪音，提升牙科治療的舒適度與效率。研究結果不僅豐富了牙科氣動渦輪手機流場和噪音生成機制的理論，也為牙科設備設計提供了實用的參考。

The primary objective of this study is to utilize Computational Fluid Dynamics (CFD) technology to simulate the flow field of dental air-turbine handpieces during idle operation and to investigate the aerodynamic acoustic characteristics affecting pressure distribution, torque features, and noise under various conditions. The study begins with the physical modeling of the dental air-turbine handpiece and setting the corresponding initial conditions for simulation. A challenge of this research lies in the need for an in-depth analysis of the flow field, requiring very fine meshing to accurately capture the dynamic changes within the internal flow field, thereby necessitating substantial computational resources. Therefore, parallel computations were carried out on a supercomputer to meet these computational demands. Through numerical simulation, this study analyzed the pressure fluctuations generated by the dental air-turbine handpiece during high-speed rotation and used Fast Fourier Transform (FFT) to study the frequency characteristics of these pressure fluctuations. Additionally, this research evaluated the impact of changes in impeller design on torque and flow field characteristics. Ultimately, by comparing the simulation results of different impeller designs, the potential for shape optimization was explored, with the aim of reducing operational noise and enhancing the comfort and efficiency of dental treatments in the future. The findings not only enrich the theoretical understanding of the flow field and noise generation mechanisms in dental air-turbine handpieces but also provide practical references for the design of dental equipment.

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