Interaction Effects in Tandem Configurations of Airfoils with Pitch/Plunging Motion

• Applicant: Professor Dr.-Ing. Cameron Tropea
• Subject Area: Fluid Mechanics
• Term: from 2006 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 27767234

Aerodynamic vortex interaction is encountered frequently in nature, either in swimming or flying and is characterized in its nature and effect by the Reynolds number (Re) and the reduced frequency (k). Whereas the region of insect flight (low Re and high k) has been extensively investigated with application to Micro Air Vehicles (MAV), the intermediate range of Re and k encountered with bird flight and fish swimming has received much less attention, especially experimentally. In this project such a tandem wing-wing facility for the low-speed wind tunnel at the TU Darmstadt has been proposed, which will allow investigation of a wide range of interference effects. By using airfoils with pitch/plunge motion the problem has been simplified to the two-dimensional case, which is advantageous both for the experimental visualization using the time-resolved particle image velocimetry technique (PIV) and for the proposed numerical simulations using Large Eddy Simulations (LES).The aim of the project is to provide insight into the potential augmentation of lift or thrust using vortex interference effects and the associated efficiency. This rather technically orientated goal is felt to be an essential preliminary step in interpreting occurrences of aerodynamic vortex interaction in nature. However also the conditions under which energy extraction from the flow is feasible will be investigated. The initial funding period concentrates on construction and qualification of the experimental facility and numerical code. An initial experimental program has been outlined and possible extensions for further studies have been proposed. In particular the investigation of biologically interesting configurations will be emphasized in the second funding period.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1207: Nature Inspired Fluid Mechanics