Loading...
|
Please use this identifier to cite or link to this item:
https://tkuir.lib.tku.edu.tw/dspace/handle/987654321/36024
|
| Title: | 二維方柱橫向與扭轉向振動耦合之氣動力研究 |
| Other Titles: | Aerodynamic forces of a square prism in transverse and torsional coupled motion |
| Authors: | 呂宜靜;Lu, Yi-ching |
| Contributors: | 淡江大學水資源及環境工程學系碩士班
盧博堅;Lu, Po-chien |
| Keywords: | 二維方柱;強制振動;頻率比;偏心量;A square prism;forced vibration;ratio of frequency;eccentricity |
| Date: | 2005 |
| Issue Date: | 2010-01-11 07:29:12 (UTC+8) |
| Abstract: | 本研究將探討一二維方柱體在受強制振動影響下，改變其橫風向與扭轉向振動間的頻率比及二維方柱之偏心量，進而瞭解橫風向與扭轉向振動間發生耦合時，結構物所產生之氣動力現象。
結果顯示，當Fr大於1.0時，在勁度中心往上游偏離，偏心量為10％時可得最小的擾動昇力係數峰值及渦散頻率的尾跡風速；而在勁度中心往上游偏離，偏心量為20％可得最大的擾動昇力係數峰值及渦散頻率的尾跡風速。當Fr等於1.0時，在勁度中心往上游偏離，偏心量為10％時可得最大的擾動昇力係數峰值及渦散頻率的尾跡風速；而在勁度中心往上游偏離，偏心量為20％可得最小的擾動昇力係數峰值及渦散頻率的尾跡風速。與Fr大於1.0正好相反。當Fr小於1.0時，在勁度中心無偏離時，可得最大的擾動昇力係數峰值及渦散頻率的尾跡風速；而最小值則不一定發生在哪一個偏心上。
Wind tunnel measurements were performed to study the aerodynamic
phenomenon of a two dimensional prism when the mass center separates from the center in transverse and torsional coupled vibration modes.
When the torsion/transverse frequency ratio (Fr) is greater than 1.0, as long as the eccentricity is introduced in the upstream direction at 10%, the spectral peaks of the lift fluctuation coefficient and the vortex shedding reach a minimum value compared with other eccentricities. However, as the eccentricity increases to 20%, the spectral peaks reach a maximum value.
Whereas when Fr=1, eccentricity 10% and 20% in the upstream direction, the spectral peaks of lift fluctuation coefficient and vortex shedding show the opposite trend. A maximum value is obtained when Fr is smaller than 1.0 and without eccentricity. However, there is no obvious trend for the minimum value. |
| Appears in Collections: | [水資源及環境工程學系暨研究所] 學位論文
|
All items in 機構典藏 are protected by copyright, with all rights reserved.
|
