查詢結果分析
來源資料
頁籤選單縮合
題名 | Dynamic Response of an Elastic Fence Under Wind Action=風力作用下二維直立彈性牆之動態反應 |
---|---|
作者姓名(中文) | 方富民; 翁駿民; 劉志義; 宋邦壽; | 書刊名 | 中國工程學刊 |
卷期 | 22:4 1999.07[民88.07] |
頁次 | 頁469-478 |
分類號 | 441.562 |
關鍵詞 | 流體誘發振動; 大渦模擬; Flow induced vibration; Large-eddy simulation; |
語文 | 英文(English) |
中文摘要 | 本文以動力數值計算的方法探討邊界層流中二維直立彈性牆在順風向之動態反應 。為了要模擬出流體與結構間之互制效應,數值方法中採用兩組控制方程式,以交替解析出 瞬間紊流流場與牆體振動之時間序列變化。結果顯示,在高雷諾數的情況下,本非恆定流場 存在兩個主頻(分別與剪力層渦流及渦散相關)。另一方面,由於受到非恆定荷重之作用, 使得牆體產生振動。於牆頂處,其運動形態係以靜力平衡位置為中心作對稱的來回振動。當 牆體之自然頻率與兩個主頻相近時,牆頂動態反應之擾動量(位移、速度與加速度)皆有極 值發生。此外,若牆體屬柔性結構時,其高模態反應會被激發,導致牆頂擾動速度與加速度 值顯著之增加。 |
英文摘要 | The along-wind response of a surface-mounted elastic fence under the action of wind was investigated numerically. In the computations, two sets of equations, one for the simulation of the unsteady turbulent flow and the other for the calculation of the dynamic motion of the fence, were solved alternatively. The resulting timeseries tip response of the fence as well as the flow fields were analyzed to examine the dynamic behaviors of the two. Results show that the flow is unsteady and is dominated by two frequencies: one relates to the shear layer vortices and the other one is subject to vortex shedding. The resulting unsteady wind load causes the fence to vibrate. The tip deflection of the fence is periodic and is symmetric to an equilibrium position, corresponding to the average load. Although the along-wind aerodynamic effect is not significant, the fluctuating quantities of the tip deflection, velocity and acceleration are enhanced as the fundamental frequency of the fence is near the vortex or shedding frequency of the flow due to the occurrence of resonance. In addition, when the fence is rather soft, a higher mode response can be excited, leading to significant increases in the variations of the tip velocity and acceleration. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。