It is desired to resolve soil contamination with reduced costs. “Insoluble treatment” is a soil improvement method for heavy metal containing soil, which uses soil mixers to mix soil and soil improvement liquid agen...It is desired to resolve soil contamination with reduced costs. “Insoluble treatment” is a soil improvement method for heavy metal containing soil, which uses soil mixers to mix soil and soil improvement liquid agents. To reduce the costs of this method, soil mixers have to be optimized. However, it is not achieved due to the lack of theoretical knowledge on mixing solid with liquid. Therefore, a numerical model to simulate the dynamic behavior of solid and liquid is on the development in this study using Smoothed Particle Hydrodynamics (SPH) method. To validate the numerical model, several experiments were carried out and numerically reproduced. The comparisons of the results showed that the numerical model replicated a liquid flow with an error rate of 2.1% and a seepage flow with an error rate up to 26.1%. Especially, the water distribution in the soil pores was highly improved with absolute gaps in volumetric water content up to 4.4% in the porosity range of 10% - 90%. For the water absorption into dry sand, the simulation result became more realistic by concerning soil suction.展开更多
A numerical model physically based on a formulation of water, vapor, and heat transport in saturated- unsaturated soils coupled with a lower atmosphere boundary layer modelling is presented. The inputs required for t...A numerical model physically based on a formulation of water, vapor, and heat transport in saturated- unsaturated soils coupled with a lower atmosphere boundary layer modelling is presented. The inputs required for the computer simulation are weather data, soil thermal and hydraulic properties. The coupled numerical model is tested separately with the experimental result and analytical solution because of the scarcity of suitable analytical solution for the coupled problem. The agreements of the numerical model with the experimental data and the analytiCal solution are excellent. Numerical experiments are performed to analyse the effects of weather conditions, soil water conductivity K, thermal vapor diffusivity DTV, and isothermal vapor conductivity DHV on the evaporation rate from the soil surface. When the soil is wet, the evaporation rate is more sensitive to the input atmospheric conditions. This is the situation for high ground water table and just after rainfall. The accuracy of the measurement of air humidity has stronger effect on evaporation rate than the roughness length. When the soil is dry enough,the soil water conductivity dominates evaporation rate. Neglecting thermal vapor diffusivity and isothermal vapor conductivity introduces an error less than 2. 5% in evaporation rate.展开更多
文摘It is desired to resolve soil contamination with reduced costs. “Insoluble treatment” is a soil improvement method for heavy metal containing soil, which uses soil mixers to mix soil and soil improvement liquid agents. To reduce the costs of this method, soil mixers have to be optimized. However, it is not achieved due to the lack of theoretical knowledge on mixing solid with liquid. Therefore, a numerical model to simulate the dynamic behavior of solid and liquid is on the development in this study using Smoothed Particle Hydrodynamics (SPH) method. To validate the numerical model, several experiments were carried out and numerically reproduced. The comparisons of the results showed that the numerical model replicated a liquid flow with an error rate of 2.1% and a seepage flow with an error rate up to 26.1%. Especially, the water distribution in the soil pores was highly improved with absolute gaps in volumetric water content up to 4.4% in the porosity range of 10% - 90%. For the water absorption into dry sand, the simulation result became more realistic by concerning soil suction.
文摘A numerical model physically based on a formulation of water, vapor, and heat transport in saturated- unsaturated soils coupled with a lower atmosphere boundary layer modelling is presented. The inputs required for the computer simulation are weather data, soil thermal and hydraulic properties. The coupled numerical model is tested separately with the experimental result and analytical solution because of the scarcity of suitable analytical solution for the coupled problem. The agreements of the numerical model with the experimental data and the analytiCal solution are excellent. Numerical experiments are performed to analyse the effects of weather conditions, soil water conductivity K, thermal vapor diffusivity DTV, and isothermal vapor conductivity DHV on the evaporation rate from the soil surface. When the soil is wet, the evaporation rate is more sensitive to the input atmospheric conditions. This is the situation for high ground water table and just after rainfall. The accuracy of the measurement of air humidity has stronger effect on evaporation rate than the roughness length. When the soil is dry enough,the soil water conductivity dominates evaporation rate. Neglecting thermal vapor diffusivity and isothermal vapor conductivity introduces an error less than 2. 5% in evaporation rate.
