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Numerical Simulations of the Flow Field around a Cylindrical Lightning Rod
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作者 Wei Guo Yanliang Liu +3 位作者 Xuqiang Wang Jiazheng Meng Mengqin Hu Bo He 《Structural Durability & Health Monitoring》 EI 2024年第1期19-35,共17页
As an important lightning protection device in substations,lightning rods are susceptible to vibration and potential structural damage under wind loads.In order to understand their vibration mechanism,it is necessary ... As an important lightning protection device in substations,lightning rods are susceptible to vibration and potential structural damage under wind loads.In order to understand their vibration mechanism,it is necessary to conduct flow analysis.In this study,numerical simulations of the flow field around a 330 kV cylindrical lightning rod with different diameters were performed using the SST k-ωmodel.The flow patterns in different segments of the lightning rod at the same reference wind speed(wind speed at a height of 10 m)and the flow patterns in the same segment at different reference wind speeds were investigated.The variations of lift coefficient,drag coefficient,and vorticity distribution were obtained.The results showed that vortex shedding phenomena occurred in all segments of the lightning rod,and the strength of vortex shedding increased with decreasing diameter.The vorticity magnitude and the root mean square magnitudes of the lift coefficient and drag coefficient also increased accordingly.The time history curves of the lift coefficient and drag coefficient on the surface of the lightning rod exhibited sinusoidal patterns with a single dominant frequency.For the same segment,as the wind speed increased in a certain range,the root mean square values of the lift coefficient and drag coefficient decreased,while their dominant frequencies increased.Moreover,there was a proportional relationship between the dominant frequencies of the lift coefficient and drag coefficient.The findings of this study can provide valuable insights for the refined design of lightning rods with similar structures. 展开更多
关键词 lightning rod flow around circular tubes numerical simulation vortex shedding phenomenon
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Limitations of Lightning Rods in Preventing Direct Lightning Strikes 被引量:1
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作者 Zhen CHEN Xiaofeng LUO +5 位作者 Jixi LIU Ziqin GAO Yixian QIU Xiaoning ZHANG Lingjin KONG Chunliang ZHANG 《Meteorological and Environmental Research》 CAS 2023年第4期59-62,共4页
Since ancient times,lightning disasters have undoubtedly been an unstoppable threat to humanity.During thunderstorms,lightning often damages objects on the ground,such as buildings and structures.Since Franklin invent... Since ancient times,lightning disasters have undoubtedly been an unstoppable threat to humanity.During thunderstorms,lightning often damages objects on the ground,such as buildings and structures.Since Franklin invented the lightning rod in 1752,lightning rods have been used worldwide to prevent direct lightning strikes in various fields such as high-voltage power transmission lines,outdoor chemical sites,highways,land and sea wind farms,and forest lightning fire protection.It has been proven that lightning accidents still occur frequently in places where lightning rods are installed and the protective angle method is used.In order to further study the protective effect of lightning rods and identify the shortcomings of lightning rod protection,negative lightning strikes are taken as the research object,to analyze the limitations of lightning rods in preventing direct lightning strikes from the working principle of lightning rods. 展开更多
关键词 lightning rod Direct lightning strike Protective angle method LIMITATION
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Application of Comprehensive Lightning Interceptor in Highway Toll Station 被引量:2
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作者 Zaiqiang YANG Yixian QIU +4 位作者 Yu HUANG Lingjin KONG Ruiliang CHEN Yan YANG Hui YANG 《Meteorological and Environmental Research》 CAS 2022年第5期56-59,共4页
Expressway toll station is listed by lightning protection experts as one of the five difficult problems in the field of international lightning protection.So far,the direct lightning protection of the expressway toll ... Expressway toll station is listed by lightning protection experts as one of the five difficult problems in the field of international lightning protection.So far,the direct lightning protection of the expressway toll station is mainly based on the electrical geometry model-rolling ball method.Lightning rod or lightning belt is installed on the high pole lamp of the toll square and the ceiling of the toll island as a flash catching device to intercept lightning.The lightning rod is a section of metal conductor with the tip.From the process of the connection between up leader generated by the lightning rod and down leader of lightning,the lightning rod has the ability to attract the lightning rod,and can prevent lightning strike of the protected objects within a certain range.From the perspective of lightning protection methods and means,lightning protection plays an interception role against lightning discharge,also called interceptor.A large number of practice has proved that the lightning rod plays an important role in protecting the building structure from lightning damage.With the development of electronic information society,the limitations of lightning rod are more and more prominent,resulting in more and more lightning strike accidents.In 2019,China invented a new flash connection device-lightning interceptor that can overcome the limitations of lightning rod and has applied it on expressways,which has achieved remarkable results.In this paper,the physical parameters of lightning receiving process by the lightning interceptor and the lightning rod are compared,and the solution to prevent direct lightning strike at expressway toll station is proposed. 展开更多
关键词 HIGHWAY lightning rod limitations lightning interceptor Multi-pulse discharge Continuous current
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Investigation on a Typical Scattered Lightning Strike Case and Response Measures 被引量:1
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作者 Wei Li Guiqiong Zhao Ping Wang 《Meteorological and Environmental Research》 CAS 2013年第7期8-9,14,共3页
From July 31 to August I in 2008, a strong thunderstorm process occurred in Neijiang of Sichuan Province, and a strange scattered light- ning strike phenomenon happened in office building of Dongxing Meteorological Bu... From July 31 to August I in 2008, a strong thunderstorm process occurred in Neijiang of Sichuan Province, and a strange scattered light- ning strike phenomenon happened in office building of Dongxing Meteorological Bureau in Neijiang. Through a series of investigations and analyses, we found occurrence reason of the scattered lightning strike and improved lightning protection measures. 展开更多
关键词 Scattered lightning strike High elevated lightning rod Preventive measures China
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Distribution Characteristics and Shielding Effects of Ion Clouds 被引量:1
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作者 Hui YANG Zhongqiu SHI +3 位作者 Renhong GUO Yixian QIU Qiaobin WEI Yu HUANG 《Meteorological and Environmental Research》 CAS 2023年第2期42-44,49,共4页
The latest research shows that the ions generated by the corona discharge of lightning rod have dual functions of attracting and shielding lightning discharge. After the lightning rod is installed at a certain height ... The latest research shows that the ions generated by the corona discharge of lightning rod have dual functions of attracting and shielding lightning discharge. After the lightning rod is installed at a certain height on the ground,the lightning rod tip reaches the corona threshold to ionize the surrounding air and generate positive and negative ions under the action of the electric field at the end of the lightning downward leader. Constrained by Coulomb’s Law,its positive ions( opposite charges attract each other) form an upward leader( streamer),which moves towards the end of the lightning downward leader and is connected to the downward leader,establishing a discharge channel to attract lightning to the needle tip and discharge the current to the ground,and playing a role in attracting lightning. Its negative ions are repelled by the electric field at the end of the lightning downward leader( repelled by isotropic charges) and influenced by the wind,and diffuse in the downwind area to form an ion cloud,inhibiting the growth of corona at the tip of ground objects,and playing a role in shielding lightning. In this paper,Franklin’s understanding of the role of lightning rod and Yang Shaojie’s new definition of the working principle of lightning rod are briefly introduced. The formation mechanism,distribution characteristics,shielding effect,and impact on lightning strike point distribution of ion clouds are analyzed. Additionally,the important role of shielding effects of ion clouds in regional lightning protection is introduced,which provides a theoretical basis for the correct understanding and use of lightning rod. 展开更多
关键词 lightning rod Ion clouds Distribution characteristics Regional lightning protection Theoretical basis
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Zeroing Instead of Grounding 被引量:1
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作者 Michael Bank 《Journal of Energy and Power Engineering》 2020年第1期33-37,共5页
This paper proposes explanation of existing methods of zeroing on basis of earth using.It is showed different constructions of several types of zeroing systems(nullifiers)for different implementations.Methods for obta... This paper proposes explanation of existing methods of zeroing on basis of earth using.It is showed different constructions of several types of zeroing systems(nullifiers)for different implementations.Methods for obtaining a zero-input impedance of a nullifier and reducing its current to almost zero without using earth are described. 展开更多
关键词 lightning lightning rod current drain COUNTERWEIGHT linear antenna single-wire system
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