Meeting Abstract

P3-16   -   A PIV study of the flow around a model owl wing with leading-edge serrations Nafi, AS*; Charland, D; Saussaman, T; Lloyd, C; Gurka, R; Coastal Carolina University; Coastal Carolina University; Coastal Carolina University; Coastal Carolina University; Coastal Carolina University anafi@coastal.edu

Owls’ flight is virtually silent, inaudible to its’ preys as well as to humans. They have special microfeatures on their wings which set them apart from other non-silent bird species. One of these microfeatures is known as leading-edge serrations; rigid miniature hook-like patterns placed at the primaries of leading-edge. Leading-edge serrations encounter the upstream flow before any other segment of the wing, act as a flow control mechanism, and supposedly alter the flow field to generate less noise. Herein, their effects on the flow field around a model owl wing are studied using Particle Image Velocimetry (PIV). Using full-scale measurements from a preserved Barn owl wing, three-dimensional wing models were reconstructed (excluding the microfeatures) and leading-edge serrations were modeled based on their overall shape and orientation. PIV experiments were conducted in a water flume on the model wing with and without leading-edge serrations at different angles of attack (0, 6, 12, 20, and 24 degrees). The Reynolds number for the experiments was 25,000 and the flow measurements were carried out in five different spanwise normal planes around the wing. Differences in the flow characteristics between the serrated and the unmodified wing model were analyzed to evaluate the effects induced by the presence of leading-edge serrations. Based on the near wake data, their aerodynamic performances were estimated and compared to determine the influence of serrations.