Acoustic and Seismic Fields of Hydraulic Jumps at Varying Froude Numbers
Acoustic and Seismic Fields of Hydraulic Jumps at Varying Froude Numbers
复制标题
不同弗劳德数下水跃的声场和地震场
DOI：
10.1002/2017gl074511
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发表时间：
2017
影响因子：
5.2
通讯作者：
Jeffrey B. Johnson
中科院分区：
文献类型：
--
作者：
T. Ronan;J. Lees;T. Mikesell;Jacob F. Anderson;Jeffrey B. Johnson
河流附近产生地震和声波场的机制知之甚少，因为缺乏与时间相关的河流条件与近河地震声波场的观测。在Harry W.爱达荷州博伊西河上的莫里森大坝（HWMD）探索了河流系统的时间变化如何影响周围的声场和地震场。调整HWMD的配置改变了河流水深，因此改变了大坝下方驻波的形式。HWMD进行调整，以产生四个不同的波的制度，参数化，通过其无量纲弗劳德数（Fr）和观测的环境地震和声波场在研究现场。为了产生可检测和相干的信号，驻波必须超过1.7的阈值Fr值，其中非破坏性的波动跳跃变成破坏性的弱水跃。水动力过程可能部分地控制地震和声能的频谱内容。此外，与可再现的波浪条件相关的谱可用于校准和验证河流地震和声学模型。
Mechanisms that produce seismic and acoustic wavefields near rivers are poorly understood because of a lack of observations relating temporally dependent river conditions to the near‐river seismoacoustic fields. This controlled study at the Harry W. Morrison Dam (HWMD) on the Boise River, Idaho, explores how temporal variation in fluvial systems affects surrounding acoustic and seismic fields. Adjusting the configuration of the HWMD changed the river bathymetry and therefore the form of the standing wave below the dam. The HWMD was adjusted to generate four distinct wave regimes that were parameterized through their dimensionless Froude numbers (Fr) and observations of the ambient seismic and acoustic wavefields at the study site. To generate detectable and coherent signals, a standing wave must exceed a threshold Fr value of 1.7, where a nonbreaking undular jump turns into a breaking weak hydraulic jump. Hydrodynamic processes may partially control the spectral content of the seismic and acoustic energies. Furthermore, spectra related to reproducible wave conditions can be used to calibrate and verify fluvial seismic and acoustic models.