Institute of Sound and Vibration Research, University of Southampton, Southampton, United Kingdom.
J Acoust Soc Am. 2011 Jun;129(6):3521-30. doi: 10.1121/1.3569706.
An analytical model of the sound power radiated from a flat plate airfoil of infinite span in a 2D turbulent flow is presented. The effects of stagger angle on the radiated sound power are included so that the sound power radiated upstream and downstream relative to the fan axis can be predicted. Closed-form asymptotic expressions, valid at low and high frequencies, are provided for the upstream, downstream, and total sound power. A study of the effects of chord length on the total sound power at all reduced frequencies is presented. Excellent agreement for frequencies above a critical frequency is shown between the fast analytical isolated airfoil model presented in this paper and an existing, computationally demanding, cascade model, in which the unsteady loading of the cascade is computed numerically. Reasonable agreement is also observed at low frequencies for low solidity cascade configurations.
本文提出了一种分析模型，用于计算二维湍流中无限展长平板翼型的声功率辐射。该模型考虑了交错角对辐射声功率的影响，因此可以预测相对于风扇轴的上游和下游声功率。本文提供了适用于低频和高频的上游、下游和总声功率的封闭形式渐近表达式。研究了弦长对所有折合频率下总声功率的影响。本文提出的快速解析孤立翼型模型与现有的计算要求较高的叶栅模型在高于临界频率的频率上表现出很好的一致性，其中叶栅的非定常载荷是通过数值计算得到的。对于低稠度叶栅配置，在低频下也观察到了合理的一致性。
