低风速条件下污秽颗粒在电力外绝缘近表面的动力模型研究

研究室外绝缘子表面的积污规律,预测一段时间内特定气象环境下绝缘子表面的积污量,对输电线路防污工作极为重要。基于流体力学和两相流的理论,研究了低风速条件下绝缘子近表面大气的流动情况,分析了污秽颗粒在近表面流体中的受力特征,建立了低风速条件下污秽颗粒在绝缘子近表面的动力模型。结果表明:低风速条件下空气在绝缘子近表面作层流运动,污秽颗粒在层流中所受的主要作用力包括:重力、浮力、气动阻力,以及因层流而产生的Saffman力,并给出了相关力的计算公式和污秽颗粒的拉格朗日方程。

Study on a Dynamic Model of Pollution Particles on the Near Surface of Electric External Insulation under Low Wind Speed Condition

It's important to study the law of contamination deposit on the outdoor insulator surface for forecasting the amount of dirt under specific meteorological environment during a period of time and for preventing flashover of transmission line.Based on the theory of hydrodynamics and two-phase flow,the flow condition on the near surface of insulators was studied and the mechanical characteristics of pollution particles in this flow on near surface were analysed.The dynamic model of pollution particles on the near surface of electric external insulation under low wind speed condition.It is found out that the air on the near surface of insulators is laminar flow under low wind speed condition,and pollution particles in it mainly suffer gravity,buoyancy,aerodynamic drag and Saffman force which is due to the laminar flow.The formulas of related forces and the lagrange equation of the pollution particles are provided.