運用田口法與數值模擬探討噴水推進器性能研究

PERFORMANCE OF WATERJET PROPULSION SYSTEM INVESTIGATED USING THE TAGUCHI AND NUMERICAL SIMULATION METHODS

本研究主要使用數值模擬方法做為試驗的平台，結合旋轉機械的滑移網格技術來解算噴水推進器三維流場之變化，並運用田口實驗設計法及統計分析的原理，有效率且系統化的設計實驗組合，設定噴水推進器產生的推力為望大的品質特性，考慮轉子葉片數、定子葉片數、定子安置角、及轉子與定子之間隙等4項控制因子，並運用實驗設計之直交表規劃試驗以進行穩健設計；將數值模擬運算所得推力值換算為信號雜訊比（S／N），作為參數設計的指標，並經由變異數的分析，探討控制因子的貢獻度與彼此之間的交互作用，進而獲得最適化的參數水準組合。結果顯示數值模擬與實驗數據的性能曲線趨勢相吻合。此外，對於轉子和定子葉片周圍的流場機制，亦做了合理的探討。

This study mainly used the numerical simulation method as the experiment platform, combining the sliding mesh technology of rotating machinery with the principles of Taguchi experimental method and statistical analysis. The sliding-mesh method was used to calculate the changes in the three-dimensional flow field of the waterjet propulsion system. The Taguchi experimental method was used to effectively and systematically de-sign experimental groups. The "larger is better" characteristic quality of the thrust of a waterjet propulsion device was configured. The control factors, such as the number of rotor and stator blades, stator placement angle, and the rotorstator gap were determined; and the orthogonal table planning test was employed to establish a robust design. The thrust value obtained from the numerical simulation calculation was then converted into a signal-to-noise ratio to serve as the parameter design indicator. Thereafter, variance analysis was per-formed to investigate the contribution of the control factors and the effect of their interactions for determining the optimal parameter level combination. The results indicated that the curve trends of the numerical simulation and the experimental data were consistent. In addition, the flow field mechanism around the rotor and stator was also investigated.