低A声级贯流风机叶片周向角不等距优化设计

叶轮产生离散噪声的原因是叶片间周向夹角均匀布置,因此降低叶轮离散噪声的有效手段就是破坏叶片周向夹角的均匀布置,通过合理布置各叶片夹角降低叶轮离散噪声。本文提出了采用叶片周向角不等距布置降低叶轮总离散噪声A声级的一种优化设计模型,模型充分考虑了A计权函数与波动力对脉动流场响应参数Sc乘积有关的综合衰减曲线的高低频段衰减较大的特性和人可听域频率范围在20-2000Hz之间的特点,通过算例验证采用该模型可以降低总离散噪声A声级。

An optimization model by using unequal spacing blades for turbine noise reduction

The fundamental cause for the turbine discrete noise is its equally spaced blades. So the most efficient way to reduce the discrete noise is to break the equally spacing fashion of the blades. This paper gives an optimization model to minimize the A-weighted sound level with the blade circumferencial angle as the design variable. The model fully takes into account the low and high frequency attenuation properties of synthesis attenuation curve, which is calculated from the moduct of the A-weighted function and the Sc parameter for the response of the fluctuating force to the fluctuating flow, and the fact the human audible sound frequency range is between 20Hz and 20000Hz. Simulation is given and the validity proved.