基于FLUENT的动态高压微射流内部孔道流场的数值模拟

 以动态高压微射流振荡反应腔内部孔道流场为研究对象，建立了反应腔内部孔道的几何模型和网格模型，选择SIMPLEC算法和RNG k-ε模型，运用FLUENT软件对流场进行数值模拟，以揭示流场内各位置上的静压和速度分布。计算结果表明：高速射流撞击增加了流场内的撞击作用力，流速的急剧增加使速度梯度迅速加大，剪切应力极大增强，保证了微射流均质机极佳的作用效果；由于反应腔内部孔道流场的静压与速度变化相反，静压的急剧变化使空穴效应及压力释放效应极大增强，空穴作用力得以强化，对微射流均质机反应腔内的材料产生“腐蚀”作用。设计反应腔内部孔道时，在保证撞击区速度的前提下，应适当减小进料速度和分流管进口拐角角度，并选用较短的出料管。

Numerical Simulation of Microchannel of Dynamic High-Pressure Microfluidization Based on FLUENT

In order to analyze the flow field within the microchannel of dynamic high-pressure microfluidization,the geometric model and mesh model are established,and the pressure and velocity distributions of the flow field in interactive chamber are obtained with SIMPLEC solution algorithm and RNG k-ε model using FLUENT software.The simulated results show that the high-speed jet flow impinging increases the acting force field,and the sharp increment of the flow velocity rapidly increases the velocity gradient and shear stress.All these ensure the excellent effect of the high-pressure microfuidization.In addition,because of the opposite change of the static pressure and velocity in the oscillating chamber,the dramatic changes of static pressure greatly enhance the effect of gas cavity and pressure release,which corrode the material of the interactive chamber.It is desirable to appropriately decrease feeding speed,reduce the fluid separation inlet corner angle,and choose a short discharge nozzle on the condition of ensuring the impinging speed when designing the internal microchannel of interactive chamber.