本文係研究三方柱體群於邊界層流中之氣動力現象。邊界層流場乃以風洞模擬出代表向然界中開闊地及城市地區之大氣邊界層流況。本實驗量測在順風向前後縱向排列及橫風向排列下,不同間距比下,對風力係數和風力頻譜所造成之影響並與單一柱體比較其異同。實驗結果顯示,間距比主控方柱體群中各方柱體之氣動力現象。而在不同邊界層流況下,風速剖面、紊流強度影響渦散作用之強弱,由於高紊流強度減弱週期性渦散使能量重新分配於較寬頻域。 An experimental study was conducted to investigate aerodynamics of a group of three square prisms in turbulent boundary flows. The turbulent flows which represent natural wind passing over open country and urban area were generated in the wind tunnel. Wind force coefficients and wind power spectrum of the square prisms arranged in tandem and side-by-side with different distance ratio were measured, and compared with that of a single prism. The results show that the aerodynamics in each square prism is strongly effected by the distance ratio. In different boundary flow, the wind velocity profile and the turbulent intensity also strongly affect the vortex shedding of the prisms. The vortex shedding is weakened at the presence of high level turbulence intensity, resulting in scattering energy fluctuations over a wider frequency range.
關聯:
力學=The Chinese Journal of Mechanics 11(3),頁185-193