A combined method of wave superposition and finite element is proposed to solve the radiation noise of targets in shallow sea.Taking the sound propagation of spherical sound source in shallow sea as an example,the rad...A combined method of wave superposition and finite element is proposed to solve the radiation noise of targets in shallow sea.Taking the sound propagation of spherical sound source in shallow sea as an example,the radiation sound field of the spherical sound source is equivalent to the linear superposition of the radiation sound field of several internal point sound sources,and then the radiated noise induced by spherical sound source can be predicted quickly.The accuracy and efficiency of the method are verified by comparing with the numerical results of finite element method,and the rapid prediction of underwater radiated noise of cylindrical shell is carried out based on the method.The results show that compared with the finite element method,the relative error of the calculation results under different simulation conditions does not exceed 0.1%,and the calculation time is about 1/10 of the finite element method,so this method can be used to solve the radiated noise of shallow underwater targets.展开更多
为了实现低成本北斗滑坡地表形变自动化监测目的,本文研制了一套基于北斗云的新型滑坡实时监测系统。包括设计了具有无线传输、云端存储以及支持Ntrip(Networked Transport of RTCM via Internet Protocol)通过互联网进行RTCM网络传输协...为了实现低成本北斗滑坡地表形变自动化监测目的,本文研制了一套基于北斗云的新型滑坡实时监测系统。包括设计了具有无线传输、云端存储以及支持Ntrip(Networked Transport of RTCM via Internet Protocol)通过互联网进行RTCM网络传输协议)协议的北斗监测接收机,开发了高效的实时数据流管理软件和高精度滑坡形变监测软件,优化了外业施工设计方案,以千元终端机、自研定位软件辅以高效云计算的解决方案为低成本滑坡监测应用提供了可能。真实数值算例结果表明,短基线情形下北斗实时监测精度E方向(东方向)优于2 mm,N方向(北方向)优于2 mm,U方向(高程方向)优于3 mm,完全能够满足滑坡高精度实时监测需求。另外,本文还将滑坡区长期北斗连续监测结果与自动全站仪精密测量结果进行了对比,两者在水平方向和高程方向上符合度均优于3 mm,具有较好的一致性。展开更多
基金Foundation item:This study was financially supported by the National Natural Science Foundation of China(Grant No.52101351)。
文摘A combined method of wave superposition and finite element is proposed to solve the radiation noise of targets in shallow sea.Taking the sound propagation of spherical sound source in shallow sea as an example,the radiation sound field of the spherical sound source is equivalent to the linear superposition of the radiation sound field of several internal point sound sources,and then the radiated noise induced by spherical sound source can be predicted quickly.The accuracy and efficiency of the method are verified by comparing with the numerical results of finite element method,and the rapid prediction of underwater radiated noise of cylindrical shell is carried out based on the method.The results show that compared with the finite element method,the relative error of the calculation results under different simulation conditions does not exceed 0.1%,and the calculation time is about 1/10 of the finite element method,so this method can be used to solve the radiated noise of shallow underwater targets.
文摘为了实现低成本北斗滑坡地表形变自动化监测目的,本文研制了一套基于北斗云的新型滑坡实时监测系统。包括设计了具有无线传输、云端存储以及支持Ntrip(Networked Transport of RTCM via Internet Protocol)通过互联网进行RTCM网络传输协议)协议的北斗监测接收机,开发了高效的实时数据流管理软件和高精度滑坡形变监测软件,优化了外业施工设计方案,以千元终端机、自研定位软件辅以高效云计算的解决方案为低成本滑坡监测应用提供了可能。真实数值算例结果表明,短基线情形下北斗实时监测精度E方向(东方向)优于2 mm,N方向(北方向)优于2 mm,U方向(高程方向)优于3 mm,完全能够满足滑坡高精度实时监测需求。另外,本文还将滑坡区长期北斗连续监测结果与自动全站仪精密测量结果进行了对比,两者在水平方向和高程方向上符合度均优于3 mm,具有较好的一致性。
