低噪声罗茨鼓风机的结构设计与内流数值模拟研究

Study on Structural Design of Roots Blower with Low Noise and Numerical Simulation of Interior Flow Field

以罗茨鼓风机为研究对象,通过气流脉动与噪声分析、低噪声结构设计及内部流场数值模拟分析,提出减少风机排气口回流冲击强度、消减气流脉动及紊流是控制气动噪声的主要途径。总结了转子叶轮型线改进、转子串接、转子扭叶、异型排气口、预进气或逆流冷却等低噪声结构设计原则。最后,运用计算流体动力学(CFD)软件FLUENT对风机内流进行数值模拟,证明三叶转子比二叶转子回流冲击强度小,逆流冷却能够大幅度降低气流脉动压力,为低噪声结构优化设计提供了理论基础。

Set the Roots blower as research object,by analyzing the air pulsation and noise,low noise structural design,and numerical simulation of interior flow field,the authors put firstly forward that to reduce the intensity of backflow impact at discharge outlet,and to decrease the flow fluctuation and the pulse flow of vortex were the main method to control air dynamic noise.The design principle of lower noise structure was summarized in the paper,such as the involute profile improvement of rotor,the bunch rotor,the helix rotor,the special-shaped vents,the pre-admission and the counter-current cooling,etc.Finally,the interior flow field of Roots blower was simulated by using the software FLUENT of computational fluid dynamics（CFD）,and it showed that the backflow impact intensity of three-lobe rotor was smaller than two-lobe rotor,and the flow fluctuation pressure of rotor could be greatly reduced by using the backflow of air cooling,which provided an important theoretical base for the optimal design of structure with lower noise level.