高雷诺数串行圆柱尾迹相互作用及能量收集

本研究重点关注高雷诺数条件下串行圆柱的尾迹相互作用及相关能量收集特性。在该体系中,上游圆柱保持固定、下游圆柱受尾迹诱导围绕上游圆柱作圆周摆动,形成类似单摆的振动模型。研究结果表明,尾迹刚度概念(最初基于大间距串行圆柱体系横向振动定义)也同样可以预测小间距情况(2～4倍圆柱直径)的尾迹诱导振动响应。该实验研究相比以往工作显著拓宽了测试雷诺数范围,最高可达1.4×10～5。结果表明小间距情况(≤2.5倍圆柱直径)可实现稳定大振幅流致振动,更适合能量收集。该研究还探索了尾迹诱导振动中的迟滞现象,分析了振动响应随雷诺数连续准定常变化的演变规律,揭示了振动启动和终止两类条件下的迟滞特性,为能量收集的应用发展提供了研究基础

OBSERVATION OF 1-TO 10-SECOND MICROTREMORS IN THE WEIHE BASIN, SHAANXI PROVINCE, CHINA

Microtremors with periods of 1 to 10 seconds were observed at 8 points in and around Weihe Basin, Shaanxi Province and in Shanghai City, China, from Marcn 20 to March 26, 1990. A middle-period seismograph with a digital recorder was employed as a mobile observation system. Spectral analysis was made on the observed microtremors.The predominant peoriod was found to be about 5 seconds at almost all stations. Amplitudes of the micro-tremors were 10 or more times larger at points where sediments are supposed to be thick than those observed on basement rocks.The amplitude of the microtremors with a period of about 5 seconds at Quanling, that is located around 1000 km apart from the sea, showed almost the same value as that obtained at Sheshan located about 60 km from the sea. These facts are important to study the origin of the microtremors and their propagation mechanism.Microtremors with periods of 1 to 10 seconds were observed at 8 points in and around Weihe Basin, Shaanxi Province and in Shanghai City, China, from Marcn 20 to March 26, 1990. A middle-period seismograph with a digital recorder was employed as a mobile observation system. Spectral analysis was made on the observed microtremors.The predominant peoriod was found to be about 5 seconds at almost all stations. Amplitudes of the micro-tremors were 10 or more times larger at points where sediments are supposed to be thick than those observed on basement rocks.The amplitude of the microtremors with a period of about 5 seconds at Quanling, that is located around 1000 km apart from the sea, showed almost the same value as that obtained at Sheshan located about 60 km from the sea. These facts are important to study the origin of the microtremors and their propagation mechanism