The Effect of Simple Vertical Fraction on Diffusion Equation with Deposition

Abstract

Natur The vertical fraction variation of eddy diffusivity was taken into consideration in the dispersion of pollutants from a point source. A power-law profile was used to describe the variation of wind speed and vertical eddy diffusivity with height above ground surface. The dry deposition of the diffusing particles at the ground surface is taken into account through the boundary conditions. The concentration of pollutants was derived assuming that the vertical diffusion is limited by an elevated inversion layer located at the top of the boundary layer "h". Also, the decay distance of a pollutant along the wind direction was estimated. The resulting analytical solutions have been applied on the emissions from Egypt's First Research Reactor at Inshas in unstable condition and Hanford diffusion experiment in stable condition. Comparisons between proposed and observed concentrations show a good agreement between the proposed and observed concentrations when α=0.81than other fractions and integer value. The results are discussed and presented in illustrative figures.

Solving of Advection-Diffusion Equation in Three Dimensions in all stabilities

“…The observed concentrations of I 131 isotope was obtained from observed experiments of the Second Research Reactor at Egyptian Atomic Energy Authority at Inshas, in the stable condition. The observed samples were from a stack of height 27 m with a roughness length of 0.6 m. The meteorological data during the experiments are considered [7,8] which is given in Table (1). The observed concentrations and predicted concentrations below the plume centreline from Eqs.…”

Studying the Effect of Two Analytical Solutions of Advection-Diffusion Equation on Experimental Data

“…The already existing observed concentrations of iodine I-131 (I131) (Essa, 2009;Essa et al, 2014) were obtained from the experiments performed to collect air samples around the Second Reactor under neutral and stable conditions. The samples were collected at a height of 0.7 m above ground from a stack of 27 m height.…”

“…The samples were collected at a height of 0.7 m above ground from a stack of 27 m height. The meteorological data of I131 isotope during the experiments under neutral and stable conditions were obtained and are presented in Table 4 (Essa, 2009, Essa et al, 2014.…”