Papers by Keyword: MC Simulation

Abstract: Thin film thermocouple (TFTC) is widely used in high temperature measurement, which is of short response time, less heat residual and integrated structure. Due to the ultra-thin structure of TFTC, the interfacial diffusion has a great influence on its reliability when exposed to high temperature environment, which leads to its performance degradation. Taking thermocouple on the turbine blade as research object, the parallel diffusion model of multilayer thermocouple is proposed based on Fick’s law. The reliability model of the protective layer, the sensitive layer and the insulating layer are established in the basis of the parallel diffusion model. According to the logical correlation among the multilayer films of TFTC, the TTF model of TFTC is given. Finally, an example of reliability model based on multilayer diffusion is simulated by Monte Carlo method, which demonstrates the feasibility of the method and model.

Abstract: The diffusion of particles adsorbed on a patchwise surface with two non-equivalentsites is investigated in the framework of the lattice-gas model. The coverage dependencies of thecenter-of-mass and Fickian diffusion coefficients are calculated for some representative valuesof the lateral interaction. We propose the analytical expressions for the diffusion coefficients.We compare the theoretical dependencies with the numerical data obtained by the kineticMonte Carlo simulations. The good coincidence of the data obtained by the two quite differentmethods corroborates strongly the approach developed to describe the particle migration onsuch complex, heterogeneous lattices.

Abstract: The diffusion of guest molecules in zeolites is investigated in the framework of a onedimensionallattice-gas model with two non-equivalent sites. The concentration dependenciesof the tracer and center-of-mass diffusion coefficients are calculated for some representative valuesof the lateral interaction between the guest molecules. Using simple ideas about moleculesdiffusion we propose analytical expressions for the diffusion coefficients. We compare the theoreticaldependencies with the numerical data obtained by the kinetic Monte Carlo simulations.A very good coincidence of the data obtained by the two quite independent different methodscorroborates strongly the validity of the proposed approach.

Abstract: We have considered the diffusion of particles in a dynamically disordered medium in the framework of a simple lattice-gas model of a reconstructive surface. Using kinetic Monte Carlo simulations we have investigated the diffusion of particles over the host lattice with moving atoms. The dynamic lattice reconstruction increases substantially the particle diffusion coefficient and changes its activation energy.