Aerodynamic Analysis Of Iced Conductors With Anti-Galloping Devices

The galloping of iced conductors will have serious disadvantageous effect on the safety of operation and even cause huge economic losses.Therefore,researchers have conducted in-depth research about the galloping and have designed various anti-galloping devices.Among them,air flow spoiler and aerodynamic damping board are used to prevent galloping by changing the aerodynamic characteristics of iced conductors.They are economical,effective and easy to install,and they have a wide industrialized prospect.However,there are limited researches about the aerodynamic characteristics of iced conductors with air flow spoilers or aerodynamic damping boards.There are three problems existed in current researches.Firstly,the researches on the influencing factors of aerodynamic characteristics are not comprehensive.Secondly,there are no researches about the influence of galloping of conductors on aerodynamic characteristics.Thirdly,the influence of wake shielding effect on aerodynamic characteristics is still not investigated.In order to solve these problems,the computational fluid dynamics software Fluent is used to conduct research in this thesis,the main research contents are as follows:1.The current judgement of galloping is based on the "quasi-static assumption",so it’s necessary to study the static aerodynamic characteristics of iced conductors with antigalloping devices.Firstly,numerical model is established to simulate the static aerodynamic characteristics of iced conductors,which are compared with the wind tunnel test results to verify the accuracy of the numerical simulation.Secondly,numerical model is established to simulate the static aerodynamic characteristics of the conductors and iced conductors with air flow spoiler or aerodynamic damping board,which are used to study the antigalloping effect of the two kinds of anti-galloping devices.Finally,studying the influence of ice thickness and anti-dance size on the static aerodynamic characteristics and analyzing anti-dance effects of the two kinds of anti-galloping devices respectively.The study shows that these two kinds of anti-galloping devices both can prevent Den Hartog galloping and Nigol galloping.2.The influence of galloping of conductors is considered,and the dynamic aerodynamic characteristics of iced conductors with anti-galloping devices is studied.Firstly,introducing the basic principles of sliding meshes,dynamic meshes and UDFs.Secondly,numerical model is established to simulate the static and dynamic aerodynamic characteristics of iced conductors with air flow spoiler or aerodynamic damping board,and the differences between the static and dynamic aerodynamic characteristics are compared.Finally,studying the influence of ice thickness,anti-galloping device size,galloping amplitude and galloping frequency on the dynamic aerodynamic characteristics.The study shows that the dynamic aerodynamic coefficient is larger than the static aerodynamic coefficient in most cases.3.The influence of the wake shielding effect is considered,and the aerodynamic characteristics of iced two-bundle conductors with anti-galloping devices are studied.Numerical model is established to simulate the static and dynamic aerodynamic characteristics of iced two-bundle conductors with air flow spoiler or aerodynamic damping board,and study the influence of bundle spacing,ice thickness,anti-galloping device size,cross-section form,galloping amplitude and galloping frequency on the dynamic aerodynamic characteristics.The study shows that dynamic aerodynamic properties are less affected than static aerodynamic properties by wake shielding effects in most cases.