Category Archives: Word of the day

Jet Propulsion

Jet propulsion is a means of locomotion whereby a reaction force is imparted to a device by the momentum of ejected matter.

Source: Rocket Propulsion Elements by G. P. Sutton & O. Biblarz

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This is how lift is not always generated

  • Lifting airfoils are designed to have the upper surface longer than the bottom.
  • Air molecules travel faster over the top to meet molecules moving underneath at the trailing edge.
  • The upper flow is faster and from Bernoulli’s equation the pressure is lower. The difference in pressure across the airfoil produces the lift.

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Dead Reckoning

The process of estimating one’s current position based upon a previously determined position, or fix, and advancing that position based upon known speed, elapsed time, and course. Also known as, “not trusting your instruments and wandering aimlessly and hopelessly lost through the sky.”