A review of flow-induced noise from finite wall-mounted cylinders

This paper reviews previous studies on the flow around and flow-induced noise produced by a finite wall-mounted cylinder (FWMC) of circular and square cross section. The flow around a square FWMC is somewhat understood. Conversely, the flow around a circular FWMC is not well understood, particularly because of the phenomenon of spanwise cellular shedding. The effect of the aspect ratio (the ratio of cylinder span to diameter) on the near wake structure has been most extensively studied in the literature. However, the effect of the height of the incoming boundary layer on the near wake structure has not been comprehensively investigated and is therefore unclear, despite it being identified as a major influencing parameter on the development of the wake. Similarly, only a few studies have been conducted on the flow-induced noise of FWMCs and there is a general lack of data on the flow-induced noise characteristics and mechanisms of an FWMCs in cross flow. Nevertheless, the amalgamation of the limited data set has led to several noise generation hypotheses: (1) lower frequency tonal noise generation is due to the development of separate structures along the span of both circular and square FWMCs and (2) that increasing the boundary layer thickness will promote tonal noise generation. •The flow-induced noise mechanisms of finite wall-mounted cylinders are reviewed.•The specific noise generation mechanisms are found to be poorly studied.•Cylinder aspect ratio and boundary layer thickness will alter the noise spectra.•Increasing aspect ratio may produce lower frequency tonal noise components.•Increasing boundary layer thickness may promote tonal noise production.