題 目：旋翼之數值模擬
研 究 生：楊 文 雄
指導教 授：林 三 益
本文研究的目的在於利用數值方法模擬分析直昇機旋翼之流場，數值方法是以上風的有限體積法來求解穩態的威爾-史托客方程式(Navier-Stokes equations)，其中在對流項中採用三階的上風有限體積法，在黏滯項中採用中央差分有限體積法，進而利用交錯方向隱式法(ADI)對時間積分，並加入隱式殘值平滑性（implicit residual smoothing）加速穩態計算的收斂性，在非慣性座標中，分別採用絕對速度和相對速度當變數,並對其結果做討論。
本數值研究是以兩片轉動葉片之物理模型、採用週期性格點技巧，分別對零升力及有升力轉子做分析及計算，其結果與實驗值都相當吻合,而所有的數值計算是在32台叢集的電腦中使用平行處理來做,並對其多個區塊的方法及之間資料的傳遞做探討,進而得到不錯的平行效率。
關鍵字：旋翼，有限體積法，平行處理，多個區塊。

Subject : Numerical Simulation of Helicopter Rotor in Hover
Graduate Student : Wen-Hsiung Yang
Advisor : San-Yih Lin
A numerical method is developed to study the hovering rotor flowfields. The method solves the compressible Navier-Stokes equations. It uses a third-order upwind finite-volume scheme for discretizing the convective terms and a second-order central finite-volume scheme for discretizing the viscous terms. A DDADI time integration coupling with an implicit residual smoothing is used for achieving fast convergence. Two types of numerical formulas by using the relative and absolute velocity as flow variables in a non-inertial reference frames are introduced and compared.
The numerical simulations are performed for a two-blade rotor on periodic O-O grid topologies for non-lifting and lifting rotors. Computational solutions show good agreement with the experiment data. All of the simulations are calculated on the 32-nodes PC cluster environment by using MPI. The multi-zone technique and data passing between processors are investigated.The efficiency of parallel computation is good.
Keywords: Hovering rotor, Finite-volume scheme, Parallel Computation, Multi-zone Technique.

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