Response of passive surface hairs in steady and unsteady Falkner-Skan boundary layers.

Arrays of biologically inspired artificial hair sensors for flow detection are being considered to provide small unmanned aerial vehicles greater platform stability through gust mitigation. Analytical models of hair sensor response to flow conditions have been previously developed, but fundamental assumptions of those models have remained essentially unvalidated. A model adaptation for non-wall-orthogonal fiber deflection was developed due to the geometric nature of the attached fibers. The current work seeks to validate this hair sensor model with wind tunnel testing results of hair sensor response to flows. Because the hair sensor arrays are not yet active, an optical fiber displacement measurement scheme and image analysis algorithms were developed to compute fiber deflection response to steady and unsteady flow conditions. Results indicate agreement between model predictions and experimental results sufficient for future sensor design employing the adapted model.