Simple def. of taper ratio
 

Does anyone have a simple, plain english definition of wing taper ratio?

Chord at tip divided by chord at root.

... which makes it a fairly useless definition if the wing is not straight tapered (which is typical for most of planes with wing mounted engines). A straight tapered wing is quite rare today, which makes the simple taper ratio a fairly unimportant number.

Volume,

If the "simple" taper ratio provided by DaveReid is a fairly useless definition and a fairly unimportant number for most planes (all your words), then can you tell us how would you use a more complicated definition?

hawk

if you will permit an outsider to jump in ......

The only time one needs to use taper ratio these days would be in the very early project stages when one is estimating fairly basic aerodynamic characteristics. Once the design has progressed beyond the back of an envelope stage there are more sophisticated methods available that account for the "proper" geometry.

In any case, the basic aerodynamics of a wing don't vary all that much with taper ratio for the usual range, so the exact definition is, as Volume says, not Very important.

Taper ratio is a tool used by designers in order approximate elliptical spanwise load distribution, with the ideal taper ratio being about 2.5:1

Wing tip length/wing root length, most basically, determining an average for the surface area flowing.

There must be an alternative formula for wings with a tip chord of zero - Think the elliptical planform of the Spitfire or Thunderbolt, or semi-elliptical derivatives thereof.