Keywords: analytical solutions, Adomian method, radioactive pollution, environmental pollution, pollutant dispersion, LES, large eddy simulation, GILTT, generalised integral Laplace transform technique, advection-diffusion equation, ABL, atmospheric boundary layer, nuclear power plants, NPP, nuclear energy, eddy diffusivity, turbulence modelling, simulation
On the new parameterisation of the eddy diffusivity for radioactive pollutant dispersion
In the present work, starting from the evolution equation for the turbulent energy density spectrum, we develop a new model for the growth of the turbulence in convective boundary layer. We apply dimensional analysis to parameterise the unknown inertial transport and convective source term in the dynamic equation for the three-dimensional spectrum. The non-linear integro-differential equation is solved by Adomian decomposition method. Using the micrometeorological parameters generated by large eddy simulation, for the first time, we employ the vertical component of the energy spectrum to calculate the eddy diffusivity (required in dispersion models). This new eddy diffusivity is used in the GILTT approach to simulate ground-level concentrations considering experimental data of Angra I Nuclear Power Plant.