基于Fluent的9R-40型揉碎机三维流场数值模拟

Numerical simulation on three-dimensional turbulence air flow of 9R-40 rubbing and breaking machine based on Fluent software

为了对揉碎机空气扰动噪声源的产生机理、噪声特性及其规律进行研究,该文运用计算流体力学软件Fluent对9R-40型揉碎机内部的流场进行了三维模拟,直观显示了揉碎机腔体内的流场特性和流动状态,并且对计算所得的风速曲线和试验测得的值进行对比,结果表明,二者最大相对误差小于8%,且得到了转速为2800r/min运动时揉碎机流场的压力分布和内部流场速度分布。通过气流流场模拟结果分析表明,低速气流从进气口经高速旋转的转子作用后,产生了旋转噪声和涡流噪声;另外,在出料直管内形成一个回流区,易造成出料口堵塞,也会产生噪声。

For studying the principle,property and law of air disturbulance noise produced by rubbing and breaking machine,the three dimensional inner flow fields were simulated with Fluent software.The simulated results could directly show its properties and state of the flow fields.Comparing numerical simulation curves with experiment data, the maximum relative error was less than 8%.The distributions of pressure and velocity of flow fields were obtained from the simulated results under the condition of rotating rate at 2 800 r/min.By analyzing the simulated results of flow field,both rotation noise and eddy current noise were produced when the low-speed airflow from inlet was affected by high-speed rotating rotor.In addition,a reversed flow was formed in the outlet,which could cause a block and produce noise.