The vertical-vertical noise cross-correlation functions(NCFs)between two seismic arrays,the Japan F-net and Chin Array phase Ⅱ,are calculated using continuous recordings during 2013-2016.After array interferometry to...The vertical-vertical noise cross-correlation functions(NCFs)between two seismic arrays,the Japan F-net and Chin Array phase Ⅱ,are calculated using continuous recordings during 2013-2016.After array interferometry to obtain bin stacked NCFs,clear body waves are retrieved at different period bands.Teleseismic direct P waves for distance 15-40 degrees are observed between short period 3-10 s while core reflected PcP/ScS waves are more obvious for longer period 30-60 s.The signal-to-noise-ratio(SNR)of the short period P waves reaches its highest point with bin widths around 20 km while SNRs of PcP and ScS increase slowly with bin width.All those body waves demonstrate clear directivity with strong signals traveling from the east.The time-lapse SNR variations for the PcP and ScS show correlation with the occurrence of major earthquakes,while the P-wave SNR demonstrates seasonal variations with additional contribution from major earthquakes.The present results suggest teleseismic body waves can be retrieved through bin stacking,though further processing is still necessary to obtain finer waveforms such as P wave triplications.展开更多
As the energy supply problem worsens, the development and utilization of marine renewable energy have become a research hotspot. The development of wave energy is moving from the near shore to the distant sea. The pow...As the energy supply problem worsens, the development and utilization of marine renewable energy have become a research hotspot. The development of wave energy is moving from the near shore to the distant sea. The power-generation efficiency of a single two-floating-body wave-energy converter is relatively low. To fully utilize wave energy and improve the wave-energy capture rate of a fixed sea area, arranging a two-floating-body wave-energy converter array is necessary. This paper first introduces the basic theory of multi-floating flow field, time-domain calculation method, and influence factor of the waveenergy converter array. Then, the development of AQWA software in Fortran language considers the effect of power takeoff. A calculation method based on ANSYS–AQWA is proposed to simulate the motion of the oscillating-buoy two-floating-body wave-energy converter. The results are compared with the experimental results from the National Renewable Energy Laboratory. Finally, the ANSYS–AQWA method is used to study the power characteristics of simple and complex arrays of wave-energy converters. The average power generation of simple arrays is largest at 0°, and the average power generation of complex arrays does not change with the wave direction. Optimal layout spacing exists for the simple and complex arrays. These findings can serve as a valuable reference for the large-scale array layout of wave-energy converters in the future.展开更多
基金sponsored by the National Key R&D Program of China(No.2018YFC1503200)National Science Foundation of China(No.42004046)。
文摘The vertical-vertical noise cross-correlation functions(NCFs)between two seismic arrays,the Japan F-net and Chin Array phase Ⅱ,are calculated using continuous recordings during 2013-2016.After array interferometry to obtain bin stacked NCFs,clear body waves are retrieved at different period bands.Teleseismic direct P waves for distance 15-40 degrees are observed between short period 3-10 s while core reflected PcP/ScS waves are more obvious for longer period 30-60 s.The signal-to-noise-ratio(SNR)of the short period P waves reaches its highest point with bin widths around 20 km while SNRs of PcP and ScS increase slowly with bin width.All those body waves demonstrate clear directivity with strong signals traveling from the east.The time-lapse SNR variations for the PcP and ScS show correlation with the occurrence of major earthquakes,while the P-wave SNR demonstrates seasonal variations with additional contribution from major earthquakes.The present results suggest teleseismic body waves can be retrieved through bin stacking,though further processing is still necessary to obtain finer waveforms such as P wave triplications.
基金Supported by the National Natural Science Foundation of China under Grant Nos.5171101175,11572094,51809083,and 51579055
文摘As the energy supply problem worsens, the development and utilization of marine renewable energy have become a research hotspot. The development of wave energy is moving from the near shore to the distant sea. The power-generation efficiency of a single two-floating-body wave-energy converter is relatively low. To fully utilize wave energy and improve the wave-energy capture rate of a fixed sea area, arranging a two-floating-body wave-energy converter array is necessary. This paper first introduces the basic theory of multi-floating flow field, time-domain calculation method, and influence factor of the waveenergy converter array. Then, the development of AQWA software in Fortran language considers the effect of power takeoff. A calculation method based on ANSYS–AQWA is proposed to simulate the motion of the oscillating-buoy two-floating-body wave-energy converter. The results are compared with the experimental results from the National Renewable Energy Laboratory. Finally, the ANSYS–AQWA method is used to study the power characteristics of simple and complex arrays of wave-energy converters. The average power generation of simple arrays is largest at 0°, and the average power generation of complex arrays does not change with the wave direction. Optimal layout spacing exists for the simple and complex arrays. These findings can serve as a valuable reference for the large-scale array layout of wave-energy converters in the future.
