建築物內風壓環境之數值模擬分析

Abstract

對於風與建築物之間的相互關係大多著重在建築物外部，顯少探討建築物內部之風壓變化。本研究為了解決位於台灣新北市新店一棟建築物地下室，其電梯門會因為東北季風或颱風來臨的時候，由於強風灌入大樓的B1地下室導致內部壓力急速升高，造成地下室內之電梯門無法順利地正常開啟。考量到人力成本與幾何模型修改的便利性，本研究採用數值模擬計算建築物內八個電梯門板之受力情況，分析不同狀況下八個電梯門的開啟狀況，並根據研究結果給出改善電梯門風壓的建議。 本研究為了排除網格數量對計算結果的影響，使用四套不同網格數量之模型進行網格獨立性驗證，並根據雷諾數判定此流場問題為紊流，故在紊流模型選用上採用Standard model，且電梯門板之受力屬於紊流邊界層中之黏性底層區域，故在靠近門板處設置較多的邊界層網格以符合黏性底層區域之 條件，藉此增加模擬的可靠性。最後根據該建築物地況周圍之氣象觀測站數據作為入口風速選取的標準，本研究計算六種風速分別為12(m/s)、14(m/s)、16(m/s)、18(m/s)、20(m/s)、22(m/s)，並求出不同風速狀況下電梯門板之受力。考量到風作用在電梯門板之力屬於正向力，故乘上電梯門與滑軌間的摩擦係數求出電梯門板因風壓所產生的靜摩擦力來判斷此靜摩擦力是否大於電梯門開啟的力道。根據模擬結果顯示在風速小於16(m/s)時皆不會有電梯門無法開啟之問題。而在風速大於18(m/s)時，才有電梯門無法開啟之狀況發生。

Most of the relation between wind and building is focused on the exterior of the building,and the wind pressure changes inside the building are rarely discussed.In order to solve the basement of a building in Xindian Dist., New Taipei City, Taiwan.When the northeast monsoon or typhoon came,the internal pressure would rise rapidly because of strong winds entering the basement of B1 in the building,which resulted in the elevator doors in the basement failing to open normally.Considering the manpower cost and convenience of geometric model modification, this study uses numerical simulation to calculate the force of eight elevator doors in the building,analyzes the opening conditions of eight elevator doors under different conditions,and according to the research results, suggestions for improving the wind pressure of the elevator door are given. In order to eliminate the influence of number of grids on the calculation results, this study uses four sets of models with different grid numbers to verify the grid independence,and judges the flow field problem as turbulent flow according to Rrynolds number, choosing Standard model as this study’s turbulence model. Moreover, the force of the elevator door belongs to viscous sub-layer region in the turbulent boundary layer,so more boundary layer grids are arranged near the door to meet the conditions of viscous sub-layer region, thereby increasing the reliability of the simulation.Finally,according to the weather station data acround the building as the standard for the inlet wind speed, the six wind speeds in this study are calculated as 12 (m/s), 14 (m/s), 16 (m/s), 18 (m/s), 20 (m/s), 22 (m/s), and obtain the force of the elevator door under different wind speed conditions. Considering that the foce acting on elevator door belonged to the positive force, the friction coefficient between the elevator door and the slide rail is multiplied to determine whether the static friction force is greater than the force of the elevaor door opening.According to the simulation results, there was no problem that the elevator door cannot be opend when the wind speed was less than 16(m/s).When the wind speed was greater than 18(m/s), the situation that the elevator door cannot be opened occured.