改进的单级风扇单音噪声解析预测模型

An Improved Analytical Prediction Model for Tonal Noise of Single-Stage Fan

关键词:  风扇  叶轮机械  单音噪声  解析预测模型  管道声学

Key words:  Fan  Turbomachine  Tonal noise  Analytical prediction model  Duct acoustic

摘要:

针对单级轴流风扇单音噪声的声模态与声功率(PWL)预测，基于早期的二维叶栅噪声解析预测模型，开发了改进的三维单级风扇噪声解析预测模型。主要目的是可以通过该预测方法快速、准确地给出声场信息以优化风扇设计方案。该模型由模拟转子粘性尾迹，求解静子表面非定常载荷以及模拟管道噪声传播三个部分组成，并采用单级轴流风扇噪声试验数据对该解析预测模型的结果进行了验证。与试验数据相比较，该解析预测模型1BPF单音噪声预测结果误差<1.5dB，2BPF单音噪声预测结果误差<5dB，同时给出了合理的周向与径向模态声场模拟结果。与传统的叶轮机噪声解析预测模型相比，该方法不仅考虑了三维几何，还可以模拟出管道内的声场结构，计算方法更为合理，噪声预测结果也更为可靠，具有很好的工程应用价值。

Abstract:

Based on the early two-dimensional cascades analytical prediction model, an improved three-dimensional single-stage fan tonal noise analytical prediction model was developed for the acoustic mode and sound power level prediction of a single-stage axial fan. The main purpose of this method is to provide the sound field information quickly and accurately so as to optimize the fan design scheme. This model consists of three parts: rotor viscous wake simulation, stator unsteady load computation and noise propagation in the duct. The results of the analytical prediction model were verified by the single-stage axial fan noise test data. Compared with the experimental data, the error of the tonal noise results predicted by the analytical prediction model is less than 1.5dB for 1BPF and 5dB for 2BPF. Besides, the reasonable circumferential and radial modal sound field simulation results were given. Compared with the early turbomachine analytical prediction model for noise, this method not only considers the three-dimensional geometry, but also simulates the sound field structure in duct. It is more reasonable for the calculation method, more credible for the results, hence this method has better engineering application value.