Definition
An airfoil shape formed by two flat surfaces meeting at a sharp angle on both the upper and lower sides, producing a cross-section that looks like two wedges joined together. It is designed for efficient flight at supersonic speeds, where sharp leading and trailing edges reduce shock wave drag.
Plain English
A wing cross-section made of straight, flat surfaces that come to sharp points at the front and back, shaped a bit like a stretched diamond. It is built for aircraft that fly faster than the speed of sound.
Context Anchor
Seen in airfoil design diagrams and discussions comparing different wing cross-section shapes.
Derivation
‘Wedge’ comes from Old English ‘wecg,’ meaning a tapered piece that narrows to a thin edge. ‘Double wedge’ simply describes the shape: two wedges back-to-back, giving sharp points at both the front and rear of the airfoil. Knowing this helps you picture the shape from the name alone.
Why Pilots Care
This shape produces lower wave drag than conventional airfoils when an aircraft flies faster than the speed of sound.
Analogy
Imagine the cross-section of a long, slim diamond shape — pointed at both ends with flat sides between. That is roughly the profile of a double wedge airfoil.
Intuition Check
Do not think of a double wedge airfoil as two separate airfoils or as a wedge added onto a wing. It is the shape of one airfoil when you look at a side-view slice through it.
Example Sentence 1
The textbook showed a double wedge airfoil as an example of a shape used on supersonic aircraft.
Example Sentence 2
Pilots studying supersonic design learn that a double wedge airfoil trades low-speed lift for reduced drag at high Mach numbers.