摘要
建筑物尖端周围大气电场畸变特征研究是大气电学的重要分支之一。假定建筑物为理想导体并与地面充分连接,通过有限差分法计算二维泊松方程,得出建筑物周围的电位空间分布。讨论建筑物尖端的高度、宽度以及相对位置对大气电场畸变的影响,结果表明:最大电场畸变系数λ_i随高度呈线性增加,且线性方程斜率随宽度增加而减小;λ_i随尖端位置沿建筑屋顶的中心线向两边呈对称递增趋势,此趋势随建筑物高度增加更为显著;λ_i随尖端宽度呈指数递减关系,且宽度对畸变系数的影响随高度增加变得尤为显著。
The effects of building tip on atmospheric electric field distortion are an important part of atmospheric electricity, especially in the research of corona layer above the inhomogeneous underlying surface, upward lightning leader and even upward lightning initiated from tall building, and also an influencing factor in lightning protection. For the account that the existing measurements are ineffectual in measuring the elec- tric intensity above the tip, numerical simulation becomes very helpful. Assuming the building to be an ideal conductor and fully connected with earth and the potential is 0, which satisfies the Dirichlet boundary condition~ three other air boundaries all satisfying Numann boundary condition and the electric potential gradient on these boundaries are constants. A two-dimensional finite difference method of calculation is used to obtain the potential distribution around the building and electric intensity near the tip in further. What＇s more, the two-dimensional finite difference equation is solved by successive over-relaxation method. The effects on the atmospheric electric field distortion by the height, width and location of building＇s tip are discussed, respectively. The result shows that ~i （maximum distort coefficient of electric field） is linearly increasing with height and the slope of linear equation is decreasing with width. ）,i shows symmet- rical increasing trend when the tip is located from＇the center to the each edge on the roof of a structure. It grows evidently with the increasing height of structure. Furthermore, Ai is declined exponentially with the tip width, particularly when less than five meters, ;~i has a sensitive response to width, and the effect on ;ti by width is more obviously presented with the increasing height. Taking no account of the extinction effect of corona layer, electric field intensification shows much greater on the top when the structure is taller and thinner. In actual problems, the effects on electric field distortion mainly depend on th
出处
《应用气象学报》
CSCD
北大核心
2013年第2期189-196,共8页
Journal of Applied Meteorological Science
基金
国家自然科学基金项目(41175003
41075003)
公益性行业(气象)科研专项(GYHY200806014
GYHY201006005)
关键词
大气电场畸变
尖端特性
高大建筑物
数值计算
distortion of atmospheric electric field
characteristics of tip
tall building
numerical simulation
