完整後設資料紀錄
DC 欄位 | 值 | 語言 |
---|---|---|
dc.contributor.author | 黃子勳 | en_US |
dc.contributor.author | 林清發 | en_US |
dc.date.accessioned | 2014-12-12T02:18:08Z | - |
dc.date.available | 2014-12-12T02:18:08Z | - |
dc.date.issued | 1996 | en_US |
dc.identifier.uri | http://140.113.39.130/cdrfb3/record/nctu/#NT853489015 | en_US |
dc.identifier.uri | http://hdl.handle.net/11536/62362 | - |
dc.description.abstract | 本篇論文藉由實驗研究,探討底部加熱之封閉垂直圓柱內因熱浮 力驅動所造成的不穩定水流,經由旋轉所引發的穩定性研究。在本實 驗中上下板溫差範圍為5℃到15℃,對於較大的測試圓柱(直徑5公分, 高10分公)施加的轉速範圍為每分鐘0轉至300轉;而另一較小的測試 圓柱(直徑2.5公分,高5公分)轉速變化範圍則為每分鐘0轉至210轉。 從水的溫度對時間的記錄結果顯示,在低轉速時其溫度振幅比 靜止時為大,且流場在某個特定的轉速範圍內確實可被穩定,另外, 在本實驗中亦發現,當流場狀態為週期振盪時,溫度振幅隨空間位 置的變化雖然相當顯著,但是空間上每個位置的振盪頻率是相同的。 最後由頻譜分析的結果發現,振盪頻率對轉速的變化並不是呈現出一 個單調的變化。 | zh_TW |
dc.description.abstract | An experimental study was carried out here to investigate the stabilization of the thermal buoyancy driven unstable water flow in a vertical closed circular cylinder heated from below by rotating the cylinder about its vertical axis. Results for the time variations of the water temperature at selected locations were obtained for the imposed temperature difference ΔT ranging from 5℃ to 15℃, the cavity rotation rate Ω from 0 to 300 rpm for a cylinder with D=5cm and H=10cm and Ω varying 0 to 210 rpm for anothr cylinder with D=2.5cm and H=5cm. Based on the results for the time records of the water temperature,t he flow can be stabilized by the cylinder rotation when the rotation rate is in a certain range. The results also indicate that at low rotation rates the amplitude of the termperature oscillation can be larger than that in a stationary cavity. The flow is in time periodic or quasi-periodic oscillation at certain higher rotation rates for the larger cylinder. It was noted that low frequency high amplitude oscillations were found when Ω was in some ranges for the smaller cylinder. significant dependence of the oscillation amplitude with the space is revealed. But the entire flow oscillates at the same frequency when the flow is time periodic. Moreover, nonmonotonic variations of the oscillation frequency with the rotation rate is clearly shown. Flow regime maps delineating the stable and unstable states in the rotating cylinders are also provided. | en_US |
dc.language.iso | zh_TW | en_US |
dc.subject | 熱浮力 | zh_TW |
dc.subject | 旋轉 | zh_TW |
dc.title | 旋轉引發之垂直圓柱內熱浮力驅動水流穩定性研究 | zh_TW |
dc.title | Rotation Induced Stabilization of Thermal Buoyancy Driven Water Flow in a Vertical Rotating Closed Cylinder | en_US |
dc.type | Thesis | en_US |
dc.contributor.department | 機械工程學系 | zh_TW |
顯示於類別: | 畢業論文 |