(179c) Study of Mass Transfer Mechanism with Interfacial Convection I: The Simulation Method and Its Validation

Investigation of interfacial mass transfer mechanism by means of computation mass transfer method is prospective with the development of computer technique. As the prerequisite, the mass transfer phenomenon must be correctly simulated to provide reliable data for analyzing, which requires a believable model for describing the overall scene of the mass transfer process. Firstly, the Rayleigh convection is simulated using random disturbance model based on Lattice Boltzmann method (LBM) and the results are compared to the schlieren observation for validation. The approach for simulation is proved believable by detailed analysis from six aspects, and it is recognized that the simulation method is superior both on controlling the numerical diffusion and capturing the characteristics of the absorption process. Furthermoreï¼?analogous to the turbulent small eddy model and surface divergence, two mechanism models to predict the interfacial mass transfer coefficient k_L are proposed with pseudo dissipation rate and surface divergence calculated from velocity field. Simulation results of 12 cases of CO₂ absorption process into different solvents fit the two proposed models well, which implies that eddies affect the interfacial mass transfer in the same manner with turbulent mass transfer, independent of the means how it is generated.

Key words:

Mass transfer; Interfacial convection; Lattice Boltzmann method; Mechanism Model

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