论文部分内容阅读
基于改进的试验装置模拟了低矮房屋模型屋盖角部突然开孔过程,研究了两种风场下瞬时风压变化及稳态阶段的风压特性。发现突然开孔时孔口处外压略有降低,瞬时内压出现脉冲负压和反向正压,导致屋盖整体风荷载发生瞬间突变;内压具有很强的相关性,孔口区域外压与内压相关性最高;内压相干函数曲线峰值与湍流强度密切相关;来流湍流强度较大时,屋盖内压功率谱衰减很快,斜风向下孔口的存在致使孔口区域外压谱能量稍微降低,风压谱能量与湍流强度正相关;在开孔率约4.8%时,屋盖角部开孔导致Helmholtz共振发生,获得的开孔惯性系数比墙面开孔情形大。
Based on the improved test device, the process of sudden opening at the roof of low-rise building model was simulated. The instantaneous wind pressure changes and the wind pressure characteristics at steady state were studied. It is found that the external pressure at the orifice decreases slightly when the orifice is suddenly opened, and the pulse negative pressure and the reverse positive pressure appear in the instantaneous internal pressure, causing the sudden change of the integral wind load of the roof. The internal pressure has a strong correlation, The correlation between pressure and internal pressure is the highest. The peak value of internal pressure coherence function is closely related to the turbulence intensity. When the turbulent flow intensity is large, the internal pressure power spectrum decays rapidly. The energy of the pressure spectrum is slightly reduced, and the energy of the pressure spectrum is positively correlated with the turbulence intensity. At the opening rate of about 4.8%, Helmholtz resonance occurs at the corner of the roof, and the inertial coefficient of the obtained aperture is larger than that of the wall opening.