偶极子噪声在均匀流管道中传播的声学模型

通过建立对流FW-H方程与薄壁边界元法相结合的混合声学模型，研究偶极子噪声在均匀流管道中的传播与散射问题.计算均匀流中的声源及其在管道中的传播，采用对流FW-H方程确定均匀流中的声波传输，采用计算流体力学方法所得流场数据确定气动噪声源，采用薄壁边界元法计算声波在管壁上产生的散射声压，并将数值计算结果与Tyler-Sofrin管道声学理论方法及声学实验所得结果进行对比.结果表明，对流FW-H方程与薄壁边界元法相结合的声学模型可用于偶极子噪声在均匀流管道中传播特性的预测，并可准确预测风扇偶极子噪声在机匣内的传播.

An Acoustic Model of Propagation of Dipole Source in Uniform Flow Duct

A convect FW-H/thin-body boundary element method (BEM) hybrid method was established to study the propagation and scattering of the dipole source such as rotor/stator interaction noise source in the uniform flow duct. The acoustic model includes the generation and propagation of the sound source. The sound source is derived from the convect FW-H equation as the existence of the uniform flow and the flow field is calculated using the computational fluid dynamics (CFD) method. The propagation is derived from the thin-body BEM. In comparison to the Tyler-Sofrin duct model, the acoustic model can effectively predict the sound field of the propagation of the dipole sound source in the uniform flow.