Abstract:

Worm tongue is an important component of the centrifugal ventilator. To investigate its influences on the vibration noise of the centrifugal ventilator, numerical simulation is conducted for the aerodynamic actuation of a certain centrifugal ventilator. Through steady computation, it is found that the structure improvement can help to reduce local vortex, which is an important factor contributing to vibration. Through unsteady simulation, it is verified that the impact of the worm tongue structure on the aerodynamic actuation is mainly featured by the amelioration of local pressure fluctuation, especially the decrease of the fluctuation at blade frequency intrigued by the outflow from impeller. Based on the numerical results for the model machine, evaluation on the variation of the vibration noise is made. The results show that improvement of the worm tongue structure is beneficial to the reduction of the vibration noise; Numerical analysis for aerodynamic actuation can provide judgments to evaluate the effectiveness of the low-noise improvement of the ventilator.

摘要：

蜗舌是离心通风机重要部位之一，为研究蜗舌型式对离心通风机振动噪声的影响，本文对某型离心通风机进行气动激励的计算仿真。通过定常计算，发现蜗舌结构型式的改进能够改善局部区域的漩涡，减小诱发振动的激励因素；通过非定常计算，发现蜗舌结构型式的改进对离心通风机气动激励的影响主要体现在局部区域压力脉动的改善，尤其是叶轮出口气流激发的叶频脉动的降低。根据计算分析结果对通风机振动噪声变化进行了预估，试验结果表明，蜗舌结构的改进能够降低通风机振动噪声，气动激励数值分析可为通风机低噪声改进效果提供判断依据。

关键词: 振动与波, 离心通风机, 蜗舌, 压力脉动, 数值模拟