Trailing edge

Summary

The trailing edge of an aerodynamic surface such as a wing is its rear edge, where the airflow separated by the leading edge meets.[1] Essential flight control surfaces are attached here to control the direction of the departing air flow, and exert a controlling force on the aircraft. Such control surfaces include ailerons on the wings for roll control, elevators on the tailplane controlling pitch, and the rudder on the fin controlling yaw. Elevators and ailerons may be combined as elevons on tailless aircraft.

Cross section of an aerodynamic surface with the trailing edge emphasised
An American Aviation AA-1 Yankee being refuelled. Its wing trailing edge can be seen with aileron (deployed downwards) and flap.

The shape of the trailing edge is of prime importance in the aerodynamic function of any aerodynamic surface. A sharp trailing edge is always employed in an airfoil.[2] George Batchelor has written about:

“ ... the remarkable controlling influence exerted by the sharp trailing edge of an aerofoil on the circulation.”[3]

Extensions edit

Other sharp-edged surfaces that are attached to the trailing edges of wings or control surfaces include:

  • On control surfaces:
  • Other surfaces:

Other equipment that may be attached to the trailing edges of wings include:

Trailing edge shape edit

The trailing edge is where the upper and lower surfaces of a wing meet. They may meet at a finite angle. Alternatively, if the trailing edge angle is zero it is described as a cusped trailing edge.[4]

References edit

  1. ^ Crane, Dale: Dictionary of Aeronautical Terms, third edition, page 521. Aviation Supplies & Academics, 1997. ISBN 1-56027-287-2
  2. ^ “It had been known from the very beginning of flight that wings with a sharp trailing edge must be used in order to obtain a well-defined lift.” von Mises, Richard (1945), Theory of Flight, Section VIII.2, p.179, Dover Publications Inc. ISBN 0-486-60541-8
  3. ^ Batchelor, G. K. (1967), An Introduction to Fluid Dynamics, p.438, Cambridge University Press.
  4. ^ Anderson, John D. (2017). Fundamentals of aerodynamics. United States: McGraw-Hill Education. pp. 332–333. ISBN 978-0-07-339810-5.