Sound from boundary layer flow over steps and gaps

作者：Catlett M Ryan^*; Devenport William; Glegg Stewart A L

来源：Journal of Sound and Vibration, 2014, 333(18): 4170-4186.

DOI：10.1016/j.jsv.2014.03.042

This study is concerned with the radiated sound from boundary layer flows over small forward and backward steps and gap configurations of similar dimension. These measurements were performed in the Virginia Tech Anechoic Wall Jet Facility for step heights that ranged from approximately 10 percent to 100 percent of the incoming boundary layer height. The results show the influence of step height and boundary layer edge velocity on the far-field sound from forward and backward steps. Neither source shows clear dipole directivity and at least the larger step heights considered in this study are shown to not be acoustically compact. A new mixed scaling normalization is proposed for the far-field spectra from both types of step. Backward steps are shown to be much weaker producers of far-field sound than similarly sized forward steps. The implications of this behavior are discussed with respect to the far-field sound measured from various gap flows.

• 出版日期2014-9-1