瓶体内表面制备类金刚石膜流场结构的格子波尔兹曼模拟

Lattice Boltzmann Simulation of Flow Field in Inner Coating of Polythylene Terephthalate Bottles

类金刚石膜(Diamond-like Carbon,DLC)具有优异的气体阻隔性能。在PET瓶体内表面制备DLC阻隔涂层时,阻隔涂层的均匀性会受到瓶体内流场结构(气压分布、速度分布等)的显著影响。本文应用格子波耳兹曼方法(Lattice BoltzmannMethod/Model,LBM)对PET瓶体内制备DLC阻隔涂层时的流场结构进行模拟,研究了送气速度、气体运动粘度系数和装置结构变化时瓶体内部流场结构的变化。研究结果表明,降低进气速度和提高气体运动粘度系数有利于减弱回流而获得层流结构;装置结构的调整能够改变瓶体内的流场结构,采用恰当的异型装置可以获得较理想的流场结构,对实验工作具有一定的指导意义。

The flow field in the growth of diamond-like carbon（DLC）,gas barrier films by RF plasma enhanced chemical vapor deposition（ RFPECVD）on the inner walls of polythylene terephthalate（PET） bottles, was simulated with lattice Boltzmann model（LBM）. The impacts of the flow field characteristics, including pressure distribution, velocity distribution of various gases, coefficients of kinetic viscosity, configuration of the gas inlet nozzle and gas flow rate, on the uniformity of DLC films were studied. The results show that the flow field characteristics significantly affect the uniform deposition of the DLC films. For instance, the back-flow can be reduced to obtain a laminar flow by decreasing the gas flow rate and increasing the coefficient of kinetic viscosity. And the geometry optimization of the gas nozzle strongly affects the flow field, and the uniformity of DLC film deposition.