An electric commuter aeroplane of mass kg flies straight and level at m s in air of…

PHYSICS · Multi-part · Fermi University Physics · Fluids & Continuum Physics · Kinematics, conservation laws and ideal flow · Kinematics, conservation laws and ideal flow

Fluids and Continuum Physics, Ch Bernoulli at work: Venturi meters, Pitot tubes and lift

Problem

An electric commuter aeroplane of mass

3000

kg flies straight and level at

60

m s

^{-1}

in air of density

1.20

kg m

^{-3}

; its wing has planform area

24

^{2}

. Take

g = 9.8

m s

^{-2}

. ((a)) Find the average pressure difference between the lower and upper surfaces of the wing needed to carry the aeroplane. ((b)) Suppose the equal-transit-time story were true, so that air over an upper surface a fraction

\varepsilon

longer than the lower surface travels faster by

\Delta u = \varepsilon U

and produces

\Delta p \approx \rho U\,\Delta u

. What percentage

\varepsilon

would the upper surface have to be longer by to produce the pressure difference found in (a)?

Browse the problem library