Presentation on theme: "Flight and other locomotion in birds. Lift of a wing Bernoulli effect – pressure is inversely related to number of particles moving in a single direction."— Presentation transcript:
Lift of a wing Bernoulli effect – pressure is inversely related to number of particles moving in a single direction (fluids). Newton’s 3 rd Law – for every action there is an equal and opposite reaction.
Sanz et al. 1996 Nature Eoalulavis hoyasi Los Hoyas, Spain Goldfinch sized bird 115mya 30my after Archaeopteryx = low speeds = high maneuverability Florescent induced photo Eoaluavis
Drag Resistance caused by friction of air moving over the surface of the wing Induced drag occurs when the air flow separates from the surface of a wing –Air moves from high to low pressures –“fills” vacuums created by wing Profile drag is due to the friction between the air and bird moving through the air –Minimized by “low profile” (aerodynamic anatomy) –i.e. thin leading edge of wing
Induced Drag D i - induced drag A - aspect ratio k - constant L - lift S - wing area V e - airspeed ρ - air density V e - Airspeed D i - drag High speed Low speed
D is the force of drag,force ρ is the density of the fluid*,density v is the velocity of the object relative to the fluid,velocity A is the reference area, andarea Cd is the drag coefficientdrag coefficient Profile Drag Airspeed D
The leading edge Vortex The “LEV” of a swift Low pressure zone On top of wing Wing wants to “fill” the low pressure zone thereby creating lift Can be used for maneuverability (each wing independent) Videler et al. (2004)