| Themes > Science > Physics > Fluid Dynamics > Flying the flag for fluid dynamics > Aerodynamics > Hydro- and Aerodynamics of Animal Swimming and Flight > Low Reynolds number aerodynamics |
The basis of any understanding of animal flight mechanics should be grounded in the fundamental properties of aerofoil properties at, for standard aeronautics applications, quite low, or moderate Reynolds numbers. For 10^3 < Re < 10^5, the aerodynamics are very sensitive to changes in geometry, freestream conditions, and for animals, the wing kinematics. The essential background can be found in a [PL83], a review article that covers many of the phenomena such as laminar and turbulent separation and reattachment that appear ubiquitous in the field. As complex as these phenomena are, the basic principles of flight, properly explained and understood, are occasionally deceptively simple. Peter Lissaman [PL96] has written an informal, illustrated essay that outlines selected, but important facts and fallacies of aerodynamic theory. Another faculty member, Bob Liebeck [Lb78] is responsible for the introduction of a design method that led to the well-known Liebeck high-lift aerofoil where pressure recovery towards the trailing edge occurs as rapidly as possible without incuring large penalties due to premature separation, while still maintaining high lift over much of the forward surface. Attention to both fundamentals and details such as these, informed the successful construction of a full scale reconstruction of a giant flying pterosaur [BMLM85]. This radio-controlled flapping wing model is the subject of a nationally distributed large-format (IMAX) movie, and is on permanent exhibit at the National Aerospace Museum in Washington DC. The development of ornithopter models and the differences and similarities between these and flying animal mechanics and aerodynamics are the subject of a recent review article in [SdL96]. Prof. Peter Lissaman also has experience in the design and formulation of the man-powered Gossamer Condor, frisbees, small-scale ornithopter models, footballs, aerodynamic shields on trucks, and the hull of an America's Cup contestant, to name but a few examples. We expect to expand this section of the document with links to PDF files containing further articles and information. Once again, watch this space. |
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