Question

A small jet airplane has a total wing area of 62.5 m2 and a mass of 7.03 104 kg.

(a) If this jet is in horizontal flight, determine the pressure difference between the lower and upper surfaces of the wings.

(b) When the speed of air traveling over the wing is 237 m/s, determine the speed of air under the wing. Use 1.29 kg/m3 as the density of air.

Answer 1

Bernoulli's Principle:According to Bernoulli's principle, in an in-compressible inviscid fluid of density , the sum of pressure head, gravitational potential energy and kinetic energy remains constant ;

so, P+* (g )*h +1/2 * *V² = constant ...................................(1)

where P=pressure

h=height from ground level

s=speed of flow

a)

M= mass of jet airplane= 7.03 10⁴ kg.

A = total wing area of 62.5 m²

Therefore, pressure difference between the lower and upper surfaces is: =

   [L=W for there]

  

  

pressure difference between the lower and upper surfaces is 11023.04 Pa

b)

V_{a =}the speed of air traveling over winds =237 m/s

and density of air is =1.29 kg/m³

from the equation number (1)

  

  

The speed of air under the wing 197.68 m/s