Aerodynamics and animal flight Flashcards
What is Newton’s 2nd law?
Force on an object is the product of the mass and acceleration
- force = mass x acceleration
What is Newton’s 3rd law?
Every action has an equal and opposite reaction
What did Henry Coanda propose?
A moving stream of fluid in contact with a curved surface will tend to follow the curvature of the surface rather than continue travelling in a straight line
What did Daniel Bernoulli propose?
Bernoulli noted that the pressure of fluid is inversely proportional to speed of flow p=1/v
What doesn’t Daniel Bernoulli’s theory propose?
Flat plate lift, upside-down flight, and why the transit time should be the same
What is the relationship between moving air and pressure?
Faster moving air: lower pressure
Slower moving air: higher pressure
What is circulatory lift and the equation to prove this?
Lift to support body weight = Cl x p x V2 x S / 2 - Cl = coefficient of lift - p = air density - V2 = air speed - S = wing area
What is a vortex?
Swirling portion of air
What is a wing tip vortex?
Air leaks around the wing tips from underneath to top = creating a wing tip vortex
- starting vortex in left in the wake
What do vortex rings create?
Lots of momentum
What is the difference between flapping and gliding?
Gliding = resultant drag force reduces speed Flapping = changing the angle of incident air flow. Change in resultant force vector angle balances drag of wings and body
Why is the separate gaits theory incorrect?
Two ends of a continuum
What are consequences for wing design?
Deviation from even downwards distribution increases power requirement
Aerodynamic efficiency of any insect wing morphology can be measured directly and analysed simply with the classical theory
