A comprehensive simulation model -- deposition, diffusion, rotation, reaction and aggregation model is presented to simulate the formation processes of ramified clusters on liquid surfaces, where clusters can disuse a...A comprehensive simulation model -- deposition, diffusion, rotation, reaction and aggregation model is presented to simulate the formation processes of ramified clusters on liquid surfaces, where clusters can disuse and rotate easily. The mobility （including diffusion and rotation） of clusters is related to its mass, which is given by Dm = Dos^-γD and θm = θos^-γθ, respectively. The influence of the reaction probability on the kinetics and structure formation is included in the simulation model. We concentrate on revealing dynamic scaling during ramified cluster formation. For this purpose, the time evolution of the cluster density and the weight-average cluster size as well as the cluster-size distribution scaling function at different time are determined for various conditions. The dependence of the cluster density on the deposition flux and time-dependence of fractal dimension are also investigated. The obtained results are helpful in understanding the formation of clusters or thin film growth on liquid surfaces.展开更多
To investigate the convection in a porous medium, a horizontal quiescent layer of one fluid saturating a porous medium heated from bottom is numerically studied using single lattice-Boltzmann method （LBM） and the ge...To investigate the convection in a porous medium, a horizontal quiescent layer of one fluid saturating a porous medium heated from bottom is numerically studied using single lattice-Boltzmann method （LBM） and the generalized Navier Stokes equation proposed by Nithiarasu et al. [P. Nithiarasu, K.M. Seetharamu, and T Sundararajan Int. J. Heat Mass Trans. 40 （1997） 3955]. Due to the rarefaction, the boundary conditions are considered as both temperature jump and velocity slip. The computational results are vahdated against the analytical results, and excellent agreement has been obtained. The results have shown that the Rayleigh number is increased with increasing temperature jump, the stabilization effect of temperature is much more significant than that of velocity slip, and the computation stability of present model is better than that of Darey and Brinkman models.展开更多
We present an inverse analysis of the conductive and radiative heat transfer problem in fibrous porous materials.The porosity and total heat transmission are simultaneously recovered in the finite-volume method and ge...We present an inverse analysis of the conductive and radiative heat transfer problem in fibrous porous materials.The porosity and total heat transmission are simultaneously recovered in the finite-volume method and genetic algorithm scheme for both uniform and nonuniform porosity distributions.We solve the heat transfer equations directly to obtain the total heat transmission that defines the objective function to be minimized in the inverse analysis.The results show that the combined scheme is an effective tool for the inverse analysis of fibrous porous materials.展开更多
基金The project supported by the Natural Science Foundation for Young Scientists of Zhejiang Province of China under Grant No. RC02069 .
文摘A comprehensive simulation model -- deposition, diffusion, rotation, reaction and aggregation model is presented to simulate the formation processes of ramified clusters on liquid surfaces, where clusters can disuse and rotate easily. The mobility （including diffusion and rotation） of clusters is related to its mass, which is given by Dm = Dos^-γD and θm = θos^-γθ, respectively. The influence of the reaction probability on the kinetics and structure formation is included in the simulation model. We concentrate on revealing dynamic scaling during ramified cluster formation. For this purpose, the time evolution of the cluster density and the weight-average cluster size as well as the cluster-size distribution scaling function at different time are determined for various conditions. The dependence of the cluster density on the deposition flux and time-dependence of fractal dimension are also investigated. The obtained results are helpful in understanding the formation of clusters or thin film growth on liquid surfaces.
基金The project supported by National Natural Science Foundation of China under Grant No.10572130the National Basic Research Programs of China under Grant No.2006CB708612+1 种基金the Research Grants Council of the Government of the HKSAR under Grant Nos.PolyU5221/05E and PolyU 5231/06E PolyUNatural Science Foundation of Zhejiang Province of China under Grant No.Y607425
文摘To investigate the convection in a porous medium, a horizontal quiescent layer of one fluid saturating a porous medium heated from bottom is numerically studied using single lattice-Boltzmann method （LBM） and the generalized Navier Stokes equation proposed by Nithiarasu et al. [P. Nithiarasu, K.M. Seetharamu, and T Sundararajan Int. J. Heat Mass Trans. 40 （1997） 3955]. Due to the rarefaction, the boundary conditions are considered as both temperature jump and velocity slip. The computational results are vahdated against the analytical results, and excellent agreement has been obtained. The results have shown that the Rayleigh number is increased with increasing temperature jump, the stabilization effect of temperature is much more significant than that of velocity slip, and the computation stability of present model is better than that of Darey and Brinkman models.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10932010,51176172,11072220 and U1262109。
文摘We present an inverse analysis of the conductive and radiative heat transfer problem in fibrous porous materials.The porosity and total heat transmission are simultaneously recovered in the finite-volume method and genetic algorithm scheme for both uniform and nonuniform porosity distributions.We solve the heat transfer equations directly to obtain the total heat transmission that defines the objective function to be minimized in the inverse analysis.The results show that the combined scheme is an effective tool for the inverse analysis of fibrous porous materials.
