Three-dimensional advection–diffusion equation with steady state was evaluated from continuous point source taking the vertical and crosswind eddy diffusivities as power law of vertical height and downwind distance with constant wind speed to get the concentration in three dimensions. Separation of variables technique and Hankel transform were used to calculate this equation. The proposed analytical solution was compared with diffusion experiment of radioactive Iodine-135 (I¹³⁵) in unstable condition at Inshas, Cairo, Egypt. A good agreement achieved between calculated and observed concentration support our proposed model.

中文翻译：

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三维对流扩散方程解析解的评价

以垂直和侧风涡流扩散率作为恒风速下垂直高度和下风距离的幂律，从连续点源评估稳态三维对流-扩散方程，得到三维浓度。变量分离技术和汉克尔变换用于计算该方程。将提出的解析解与在埃及开罗 Inshas 的不稳定条件下放射性碘 135 ( I ¹³⁵ ) 的扩散实验进行了比较。计算浓度和观测浓度之间达成的良好一致性支持我们提出的模型。