Tubercled Wing Flow Physics and Performance

This chapter provides a review of the current understanding of both the potential performance effects conferred by the application of tubercles as well as our understanding of the mechanisms by which these effects are produced. While it is clear that tubercles can both beneficially and detrimentally affect performance, depending on the flow conditions, the mechanism by which this occurs and the influence of Reynolds number remain active topics of debate. The following discussion describes nine different flow mechanisms that have been proposed to explain the observed performance effects, as well as our state of knowledge of Reynolds number effects. The influence of tubercle geometric parameters such as the amplitude-to-wavelength ratio (A/λ) and amplitude-to-chord ratio (A/c) are shown to be important. Finally, the effects of tubercles on wings of finite aspect ratio (AR) and sweep, both of which influence the large-scale three-dimensionality of the flow, are also discussed.