Impingement of a propeller-slipstream on a leading edge with a flow-permeable insert: A computational aeroacoustic study
Impingement of a propeller-slipstream on a leading edge with a flow-permeable insert: A computational aeroacoustic study
复制标题
螺旋桨滑流对带有透流插入件的前缘的冲击：计算气动声学研究
DOI：
--
复制
发表时间：
2018
影响因子：
1
通讯作者：
D. Ragni
中科院分区：
文献类型：
--
作者：
F. Avallone;D. Casalino;D. Ragni
本文描述了一个拖拉机螺旋桨滑流对挂架前缘冲击的气动声学计算研究。流场和声场的研究两个挂架前缘：一个固体和一个流动可渗透的。计算设置重复了在德尔夫特理工大学进行的实验。计算结果进行了验证，对测量。结果发现，安装流动可渗透的前缘插入物在塔架的后掠叶片侧产生较厚的边界层。这是由螺旋桨尾流的螺旋运动引起的空气动力学不对称引起的，螺旋桨尾流促进了从挂架的前进叶片侧到后退叶片侧通过空腔的流动运动。可透流的前缘插入件仅在朝向后缘的塔架后退叶片侧减轻表面压力波动的幅度，从而降低结构噪声。此外，它导致近场噪声的减少，只有在塔柱后退叶片侧的上游方向定向的接收器角度。在接收器角度的该范围内，发现可透流的前缘插入件减小了第三和第四叶片通道频率的音调峰值的振幅，但是强烈地增加了高于第七叶片通道频率的频率的宽带噪声。
This manuscript describes an aeroacoustic computational study on the impingement of a tractor-propeller slipstream on the leading edge of a pylon. Both the flow and acoustic fields are studied for two pylon leading edges: a solid and a flow-permeable one. The computational set-up replicates experiments performed at Delft University of Technology. Computational results are validated against measurements. It is found that the installation of the flow-permeable leading-edge insert generates a thicker boundary layer on the retreating blade side of the pylon. This is caused by an aerodynamic asymmetry induced by the helicoidal motion of the propeller wake, which promotes a flow motion through the cavity from the advancing to the retreating blade side of the pylon. The flow-permeable leading-edge insert mitigates the amplitude of the surface pressure fluctuations only on the pylon-retreating blade side towards the trailing edge, thus reducing structure-borne noise. Furthermore, it causes a reduction of the near-field noise only for receiver angles oriented in the upstream direction at the pylon-retreating blade side. In this range of receiver angles, it is found that the flow-permeable leading-edge insert reduces the amplitude of the tonal peaks for the third and fourth blade passage frequency, but strongly increases the broadband noise for frequencies higher that the seventh blade passage frequency.