屋頂通風器空氣動力學特性實驗與理論探討

Experimental and Numerical studies of Rooftop Ventilator's Aerodynamics

楊恭年(Kung-Nien Yang)

指導教授 ： 陳增源

淡江大學/工學院/航空太空工程學系碩士班/碩士(2018年)

https://doi.org/10.6846/TKU.2018.00142

摘要

本研究為探討一般渦輪通風器與巨亞機械股份有限公司所提供之改良型通風器之空氣動力學特性比較。改良型通風器係以靜態通風器為基礎，結合動力段使其具旋轉功能。首先，以現有的兩型通風器做初步的風洞實驗，將通風器至於風洞下游，通風器下方連結一圓筒作為通風管，風洞出口的底端放置一隔板以模擬地板效應。研究結果顯示，兩型通風器在同樣風速下轉動，兩種通風器轉速相近，抽風的效果大致上相同，且改良型通風器能藉由通風器離隔板的距離增加，增加抽風效果，最後抽風效果超越渦輪通風器；再模擬通風器轉軸故障而無法轉動情形，以外力使通風器在受風下不轉動，結果顯示，渦輪通風器會形成空氣倒流現象，而改良型通風器則因為本身的外觀設計下，抽風效果依然存在，隨著風源風速增加下，抽風效果也越來越好，由數據觀察得出，改良型通風器的主要抽風效果來自外罩設計，而渦輪通風器則是來自轉動的離心效應。接著以CFD套裝軟體ANSYS Fluent進行數值模擬，結果顯示，除了渦輪通風器在不轉動下仍存在抽風效果外，其原因為風源條件及幾何相似度不同所導致，而通風器抽風效果的趨勢大致上與實驗相同。

關鍵字

風洞實驗 ； 渦輪通風器 ； 改良型通風器 ； CFD

並列摘要

This research investigated the aerodynamic characteristics of rooftop ventilators. The ventilators used in this research are the traditional turbine type and the modified type developed by Great Asia company. First of all, the experimental results show that two types of ventilators roughly have the same ventilation effect. However, the ventilation rate of modified ventilator increases as height of base frame increases. The investigations in non-rotating condition show that the turbine ventilator causes the backflow in the gap. On the contrary, the modified ventilator still has good ventilation effect of exhaust because the geometry design of the model. As the wind speed increase, the ventilation effect is getting better. According to the research, it shows that the main effect of exhaust of the modified ventilator comes from the geometrical design of the shell, and the turbine ventilator comes from the centrifugal effect. The results of numerical study are, in general, in good agreements with the experimental results, except in non-rotating condition. The CFD results can show the physical characteristics of ventilators.

並列關鍵字

Wind tunnel test ； Turbine ventilator ； Modified ventilator ； CFD

參考文獻

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