屋頂通風器抽風特性之數值模擬

Numerical Study on Air Extraction Performance of Rooftop Ventilators

黃治誠(Chih-cheng Huang)

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(2019年)

https://doi.org/10.6846/TKU.2019.00617

摘要

本研究目的是探討傳統渦輪型通風器與由我們改良過後的改良型通風器之吸風特性做比較。我們的改良型通風器是將渦輪通風器的上蓋移除，並更換為一款低壓通風裝置。首先使用CATIA繪製兩款通風器外型，接著使用FLUENT針對兩款通風器在不同高度底座受風時轉動及不轉動的情況下進行模擬，並就結果進行分析。模擬結果顯示渦輪型通風器在低底座不轉動時，會產生倒灌現象，而改良型通風器則一樣保有吸風效果；在轉動時，改良型通風器在各風速吸風效果都優於傳統型通風器，尤其在低風速時效果最佳。在底座加高至16公分時，傳統型通風器在不轉動時的倒灌情況有所改善，而改良型通風器的抽風效果在底座加高後也有大幅度的成長。

關鍵字

渦輪通風器 ； 改良型通風器 ； 計算流體力學

並列摘要

This research numerically investigated air extraction performance of rooftop ventilators, including the conventional turbine ventilator and a modified ventilator. This newly developed ventilator is modified from the conventional ventilator, where its top cover is removed and replaced by a low-pressure ventilation device. A Computational Fluid Dynamics (CFD) analysis is performed to explore the flow fields around and inside the rotating and non-rotating ventilators, and the air extraction performance. The air extraction rate is obtained from the mean velocity at the inlet of an open channel, connected to a ventilation tube. Results show that the modified ventilator exhibits better ventilation effects than the conventional one at all of the investigated wind speeds, especially at low speeds. When the ventilator is not rotating, the modified ventilator is still able to extract air out of the ventilator, while the conventional ventilator has negative air extraction rate. However, when the base is increased to 16 cm, the conventional ventilator exhibits positive air extraction rate when not rotating.

並列關鍵字

Turbine ventilator ； Modified ventilator ； CFD

參考文獻

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