依据流体力学基本原理和质量、能量守恒定律,建立了方形管流体系中的流体力学和传质模型.同时,利用壁函数和k-ε湍流运动模型,采用SIMPLE算法,在数值计算介质流速场和介质中氧浓度场的基础上,进一步地计算了介质流动产生的表面切应力和氧在流体边界层中的传质系数,研究了表面切应力和传质系数与介质流速、碳钢流动腐蚀速率问的关系.结果表明,介质运动的速度场、能量场(湍流动能和耗散能)和介质中氧的浓度场在流体边界层中的变化特别大.流场变化对近壁处的流体力学参数将产生明显的影响,近壁处的流体力学状况和传质过程与流动腐蚀有着密切的关系.
The numerical hydrodynamic models and mass transfer models for a square flow loop system were defined in accordance with the basic theory of hydrodynamic and conservation principle of mass and energy.The surface shear stress and mass transfer coefficient of oxygen in the square flow loop system were further calculated on the base of velocity field and concentration field which were numerically calculated by SIMPLE with wall function and k-εturbulence model.The relationship of surface shear stress and mass transfer coefficient with velocity of chloride solution and flow induced corrosion rate of carbon steel was also studied.It was found that there were great changes of velocity field,energy field(turbulent kinetic energy and dissipation energy)and concentration field of oxygen in hydrodynamic boundary layer.The changes of velocity field had great influences on the near-wall hydrodynamic parameters.There was a close relationship of near-wall hydrodynamic and mass transfer process with flow induced corrosion.