一种超高转速风机转频噪声分析与控制

Analysis and Control of Rotating Frequency Noise Induced by High-speed Rotation of Fan Machines

高转速风机具有体积小,效率高,可靠性高等优异特性,在家用产品、高端制造以及航空航天等领域应用前景广阔。随着转速的提高,风机的激励力和噪声将发生很大变化,高转速对噪声设计提出了更高的要求。本文对某型15万转风机的转频噪声进行研究,首先对风机转子系统不平衡力进行分析,随着转速升高转子不平衡力对其振动噪声的影响越发显著,风机低噪设计需要转子系统偏心质量更小,同时指出对转子系统和叶轮进行整体动平衡操作,可以有效降低系统不平衡激励,转频噪声降噪效果更优。进一步地,针对风机进风口来流状态对转频噪声的影响进行讨论,发现进风口不均匀来流会激发叶轮-转子系统产生不平衡激励,从而导致风机转频噪声恶化。因此风机与整机系统匹配设计时,必须考虑风机进风口结构的影响。最后综合风机转子系统的整体动平衡方案及进风口来流均匀设计等措施,该高转速风机转频噪声下降明显,收到良好的降噪效果。

High-speed fans have excellent characteristics such as small size,high efficiency,and high reliability,and have broad application prospects in household products,advanced manufacture,and aerospace engineering.With the increase of speed,the excitation force and noise of the fan have changed greatly compared to traditional low-speed fans.Highspeed design poses higher requirements for noise design.This article focuses on the research of the rotation frequency noise of a 150000 rpm fan.Firstly,the unbalance force of the fan rotor system was analyzed,it was found that the influence of rotor unbalance on vibration noise becomes more critical as the rotation speed increases.The low-noise design of the fan requires a smaller eccentric mass of the rotor system to reduce the size of the system's unbalanced force,and the overall dynamic balance of the rotor system and blade needs to be processed to achieve the best frequency noise reduction effect.Additionally,the article discussed the effect of the inlet flow condition at the fan inlet on the rotation frequency noise,finding that uneven inlet flow can excite the unbalanced excitation of the rotor-blade system,leading to the deterioration of fan rotation frequency noise.Therefore,when designing the matching system between the fan and the whole machine,the design of the fan inlet must be taken into consideration.Finally,comprehensive measures,including overall dynamic balance of the fan rotor system and uniform design of inlet flow,were implemented,resulting in significant reduction of rotation frequency noise in this high-speed fan and a good noise reduction effect.