【摘要】 采用RNG k-ε模型、多重参考系法对平直叶桨搅拌槽内高黏流体湍流流场进行数值模拟,分析搅拌槽内流体的流动特性和混合过程。结果表明:平直叶桨搅拌槽内流体主要做周向运动,流体的轴向运动和径向运动较微弱;增加的上层桨能显著提高下层桨以上流体的流动速度,但不能显著提高下层桨以下流体的流动速度;双层桨距离较近时会互相影响,导致两桨间的循环流现象消失;双层桨搅拌槽内示踪剂在扩散开始阶段主要是以团状的形式绕搅拌轴做旋转运动,之后在铅垂面上以环绕状形式在桨端周围扩散。研究结果为平直叶桨搅拌槽的设计和应用提供参考。更多还原

【Abstract】 The numerical simulation of high-viscous fluid turbulent flow field in a straight-blade agitated tank was carried out by RNG k-ε model and multi-reference frame,and the flow characteristics and mixing process in the stirred tank were analyzed.The results show that the fluid in the straight-blade agitated tank mainly moves in the circumferential direction,and the axial movement and radial movement of the fluid are weak. The increased upper paddle can significantly increases the flow velocity of the fluid above the lower paddle,but can not significantly increases the flow velocity of the fluid below the lower paddle. When the two-layer paddles are close to each other,they will affect each other,resulting in the disappearance of the circulation between the two paddles. The tracer in the double-layer paddle agitated tank mainly rotates around the stirring shaft in the form of agglomerate at the beginning of the diffusion,and then spreads around the paddle in a wraparound manner on the vertical plane. The research results provide reference for the design and application of straight-blade agitated tank.更多还原