摆动式搅拌槽内宏观流场的数值模拟

搅拌设备效率的高低在很大程度上取决于其内部流场的结构,因而对流场的研究就十分重要.采用FLUENT软件对自行设计的摆动式搅拌槽内的流场进行数值模拟,模拟时运用动网格技术来指定搅拌器的运动规律,采用标准k-ε模型对速度场进行了求解.结果表明:槽内的流场为充分发展的湍流,摆动式搅拌为径向流搅拌,桨叶上方的流动以切向剪切为主,下方以径向流为主.

Numerical simulation of the flow field in a stirred tank with a pendulum agitator

The flow field has great influences on the mixing efficiency of stirred equipment. A new kind of pendulum agitator was studied, and some complements were obtained by the application of FLUENT software. A standard k-ε turbulent model was used to predict the flow field, and the dynamic——mesh technique was applied to regulate the motion of the impeller. The simulation results show that the flow field generated by the pendulum agitator is highly complicated turbulence. The flow is mainly tangential and radial, which indicates that a reciprocating stirrer is a kind of radial flow stirrer. The velocity of the flow field in the upper zone of the tank is on average higher than that of the lower zone, which is dominated by tangential flow. The flow is mainly radial near the bottom of the tank.