Research On Collision Coefficient Of Transmission Lines During Aeolian Vibration

The collision coefficient is one of the important parameters of the transmission conductor ice prediction model,which is crucial to the accuracy of ice accumulation calculation.At present,collision coefficient related studies mainly focus on fixed conductors,and few relevant studies considering the aeolian vibration factor are found.For this reason,this paper investigates the collision coefficient and collision process of transmission conductors under aeolian vibration conditions.The main work and conclusions are as follows.(1)Based on the equation of motion of the wire aeolian vibration,a finite element model of the transmission conductor under aeolian vibration is constructed in Fluent software by UDF,DPM and Dynamic mesh.Based on the basic concept of transmission conductor collision coefficient,a collision coefficient calculation method is proposed which takes into account the transmission conductor motion factors.(2)Using the Euler-Lagrange method,CFD simulation is performed to calculate the transmission conductor under aeolian vibration conditions,and the effects of transmission conductor diameter,overcooling water droplet diameter,aeolian vibration amplitude,frequency and conductor motion speed on the transmission conductor collision coefficient are analyzed.It is found that the collision coefficient is negatively correlated with the transmission conductor diameter,and positively correlated with the diameter,amplitude,frequency and speed of wire motion of the overcooled water droplets.Amplitude,frequency and wire motion speed and collision coefficient is positively correlated may be due to the increase in the collision range of the transmission line per unit of time resulting in higher collision coefficient.(3)The collision coefficient of the aeolian vibration wire with different wire motion speed is calculated and the effect of wind speed on the collision coefficient is analyzed.The maximum speed of the wire is 0.628m/s,the collision coefficient increases with the increase in wind speed,and the rising trend gradually slows down.When the maximum speed of the guidewire is 6.28m/s,the collision coefficient decreases with the increase of wind speed,and the decreasing trend gradually slows down.When the maximum speed of the wire is 15.7m/s,the collision coefficient decreases with the increase of wind speed,and the decreasing trend of the collision coefficient is influenced by the amplitude and frequency.When the amplitude is larger,the decreasing trend is in the form of exponential.At higher frequency,the collision coefficient gradually decreases.(4)The air flow field and the trajectory of overcooled water droplets of the transmission conductor vibrated by breeze were studied,and the effect of aeolian vibration on the air flow and overcooled water droplets around the transmission conductor was discussed.It is found that the aeolian vibration dynamically changes the flow field state and collision range around the conductor.The faster the conductor moves,the stronger the disturbance effect on the overcooled water droplets.The higher the wind speed,the stronger the inertia of the overcooled droplets and the smaller the collision range.There is a saturation limit for the effect of increasing frequency on the collision range.