在設計製造風扇的過程中,因應不同需求而有不同的風扇葉片外型、尺寸及角度的設計。為了達到快速開發之目的,結合電腦輔助設計與工程分析軟體進行風扇流場與噪音分佈之模擬分析,探討不同參數所呈現之風扇性能曲線及噪音分佈,以選擇符合需求的設計,最常為業界採用的方式。 本研究針對室內空調通風所使用軸流式排風扇之設計需求,利用計算流體力學商用軟體FLUENT進行分析,運用多重參考系統(MRF)描述風扇轉動部分與固定部分,並採用有限體積法(FVM)求解質量、動量守恆方程式,以模擬風扇運轉時空氣流場。更進一步運用計算的結果,進行空氣流動所形成噪音分佈。結果顯示裝設一個風扇葉片直徑580mm、轉速900至1500rpm、裝設角度40°,或裝設兩個風扇葉片直徑390mm、轉速1200至1500rpm、裝設角度38°或40°之流量與噪音較符合所規畫適用於居家室內空調通風的軸流式排風扇之需求。
During the design and manufacturing process of a fan, various shapes, size of the blade and installing angle are designed for different requests. Reaction to the rapid market demands, the CAD and CAE analyses are applied to analyze the fluid flow field and noise distribution of a fan for different parameters to satisfy the required fan performance and noise level. In this study, numerical investigation of fluid flow and noise distribution of an axial-flow fan for air-conditioning is conducted by using FLUENT computational fluid dynamics software that MRF(Multiple Reference Frame) is adopted to describe the rotation parts as well as static parts of a fan and finite volume method(FVM) is applied to solve the mass, momentum equations. The results show that the 1st set with blade diameter 580mm, installing angle 40 degree, rotating between 900 to 1500 rpm, or the 2nd set with blade diameter 390mm, installing angle 38 or 40 degree, rotating between 1200 to 1500rpm, satisfy our design requirements.