Delta wings
The Indian Air Force recently inducted the French made Dassault Rafale into its fleet. One of the key features of the Rafale is the Delta Wing. The indigenous aircraft LCA Tejas also has delta wings. So what makes delta wings so attractive on a fighter aircraft?
When compared with the other fighter aircraft such as the F/A-18 or the F-15 or F-16, which have a sweptback wing, the delta wing offers a larger wing span area. A higher wing span area results in a lower wing loading which is the ratio of the body mass to the wing area. The benefit of a lower wing loading ensures greater lift capabilities at lower speeds, meaning that the aircraft can take-off and land at lower speeds.
Fighter aircraft travel at supersonic speeds due to which they encounter wave drag, which is a drag component present only at supersonic speeds. The delta wing has a relatively low thickness which reduces wave drag. However, the aspect ratio in delta wings, which is a ratio of the total wing span to the square of the wing area, is low. Consequently, the lower aspect ratio leads to a higher viscous drag. Although it can be argued that delta wings are beneficial only at supersonic speeds, they offer a good compromise for fighter aircraft due to their low speed capabilities.
