行政院農業委員會台南區農業改良場   研究彙報第62號

 

應用電腦輔助工程設計軟體進行負壓風扇扇葉頻率分析之研究

楊清富、林聖泉

摘  要

  楊清富、林聖泉。2013。應用電腦輔助工程設計軟體進行負壓風扇扇葉頻率分析之研究。臺南區農業改良場研究彙報62 :50-60。

  在臺灣地區,負壓風扇廣泛用於溫室的降溫,由於高排風量的需求,其風扇葉片外形都經過特殊設計,並透過靜態及動態平衡以降低運轉時的噪音及振動。但為了栽培作物的需求越來越多動力設備安裝在溫室內,運轉時形成振動源,此外力激振頻率如與扇葉自然頻率相同,則將導致共振現象的發生。因此如能獲得風扇扇葉的自然頻率,即可判定有無共振的疑慮。為求解負壓風扇扇葉的自然頻率,本研究透過SolidWorks Simulation 分析工具針對負壓風扇扇葉進行頻率分析。結果顯示,靜態無旋轉時,其前五個自然頻率分別為10.354、10.437、10.461、10.501及10.642 Hz。加上額定轉速之旋轉效應時,葉片受離心力拉伸使葉片勁度提高,也改變了其自然頻率。其前五個自然頻率分別為11.509、11.542、11.577、11.627及11.658 Hz。

關鍵詞:自然頻率、模態分析、負壓風扇
接受日期:2013年4月22日


The Frequency Analysis of Blades of Negative Pressure Fan
by Using Computer-Aided Engineering Software

Yang, C. F., T. C. Lin

Abstract

   In Taiwan, negative pressure fans are used to cool down the greenhouses widely. Due to the requirement of high airflow capacity, the shape of blade is designed specially in statically and dynamically balances for low noise and low vibration. More and more power facilities are installed in the greenhouse for assisting crop growth, which results in more vibrations when in operation. If the external excitation frequency coincides with the natural frequency of the fan blade, the resonance phenomenon will occur. Hence, if the natural frequency of the fan blades is known beforehand, the resonance can be avoided. In order to evaluate the natural frequency of the negative pressure fans, we did the frequency analysis of the fan blades by SolidWorks Simulation software. The results shows the 5 lowest natural frequencies of the fan blades are 10.354, 10.437, 10.461, 10.501, 10.642 Hz respectively, when fan is not in operation. The centrifugal force will induce more stiffness of the blade when fan is in operation, which changes the natural frequency slightly. The 5 lowest natural frequencies of the fan blades become 11.509, 11.542, 11.577, 11.627, 11.658 Hz respectively.

Key words: Natural Frequency, Modal Analysis, Negative Pressure Fan
Accepted of publication: April 22, 2013


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