Storyboard

The aerodynamics of the airfoil is the central module of the system: it describes how the geometry of the wing (E1, E2) interacts with the fluid (E8) to generate the lift and drag forces (which feed E9). It is the module where geometry becomes force. The equations of this module are the same as those of classical aeronautics, but applied to the specific conditions of birds: intermediate Reynolds numbers (10 - 10), profiles that change geometry in real time, and transient flow conditions during churning.

The Reynolds number (Re = Vc/) is the most important dimensionless parameter to characterize the aerodynamic regime of a bird: it defines the relationship between inertial and viscous forces in the flow. Small birds (hummingbird: Re ~ 10) operate in a regime where air viscosity is very important and boundary layer effects dominate. Large birds (albatrosses: Re ~ 10) operate in a quasi-turbulent regime where inertial effects dominate and profiles function more similar to airplanes.



Central physical principle: L = ½V²S·C_L and D = ½V²S·C_D: lift and drag are proportional to the square of the speed, the wing area and the dimensionless coefficients C_L and C_D. The drag polar C_D = C_D0 + k·C_L² summarizes all the aerodynamics of the wing in a single curve. (L/D)_max = 1/(2·sqrt(k·C_D0)) is the maximum fineness: the most important aerodynamic efficiency parameter of the bird.

>Model

ID:('ky', 287)

Description

ID:(0, 287)