For non technical Fanboys here to understand what prominent posters
@Oscar and
@Nilgiri are in discussion here
Let me make simple matter for Fanboys
DELTA WING:
It is one of the most common wing planform that resembles a Triangle or Δ structure.
There are mainly 4 variations of Delta wing configuration.
1. Tail-less Delta (LCA)
2. Tailed Delta (Mig-21)
3. Compound Delta (LCA)
4. Cropped Delta (F-16)
Tailed-Delta has better handling where as Cropped-Delta has better AoA. Compound Delta is used to create high-lift vortex and reduce drag. Although use of canards and control surfaces like Dassault Rafale and EF Typhoon can provide other variations too.
At the beginning Delta wing is experimented on high speed supersonic aircraft to achieve more stability during supersonic flight. But this causes instability in subsonic speed i.e below MacH.Generally Pure Delta configuration is preferred for designing Aircraft with supersonic Interceptor role. But as generation advanced Interceptors are no more required and what we call as Multi-role or Swing-role fighter comes into view. So pure Delta configuration idea is dropped out instead Compound delta and Canard-delta is used now-a-days.
ADVANTAGES:
-The Delta wing reduces the shock wave produced during the transition from subsonic to supersonic mach thus reducing the drag at higher mach. So now aircraft doesn't have to sacrifice any internal energy to compensate for the air drag.
-The delta planform gives the largest total wing area (generating useful lift) for the wing shape, with very low wing per-unit loading, permitting high maneuverability in the airframe at higher mach.
-Also Delta wing aircrafts can carry more internal fuel and ammunition because they are more stronger than swept wing planform as their fuselage Centre of gravity is far in front.
-In delta wing, at higher AoA the leading edge of wing creates a vortex which gives a high stall angle.
-As the delta wing is simple, it can be made very robust, and relatively inexpensive to build as well as simple to manufacture. That's why we see so many aircraft with Delta wing configuration. Mig-21, Typhoon, Rafale, Tejas.
LIMITATION:
-The tail-less delta doesn't provide enough lift and sufficient stability at lower mach or subsonic speed which is very important in dogfight. But it can be compensated by providing a compound delta configuration. The best example is HAL Tejas, which is a tail-less delta but with compound delta configuration.
-In canard-delta i.e EF.Typhoon or D.Rafale as the mach number increases so as the centre of lift shifts. But this is a minor drawback which can be compensated with skilled pilot.
- In T-tail delta configuration it gives rise to deep stall condition as airflow over the wing is reduced
The Tejas is a tailless, compound delta planform. This planform is designed to keep the Tejas small and lightweight. The use of this planform also minimises the control surfaces needed (no tailplanes or fore planes, just a single vertical tailfin), permits carriage of a wider range of external stores, and confers better close-combat, high-speed, and high-alpha performance characteristics than conventional wing designs. Extensive wind tunnel testing on scale models and complex computational fluid dynamics analyses have optimised the aerodynamic configuration of the LCA, giving it minimum supersonic drag, a low wing-loading, and high rates of roll and pitch
