Delta Wings

By: Karthik Govil

Definition:

Delta wings are triangle shaped wings, the name coming from the delta shape.

Introduction:

Delta wings have a long history of being used in aeronautics. They were first used in WW1 too increase efficiency at supersonic speeds. Their shape was progressively modified over time to reduce the high drag produced at low altitudes.

 

Types of Delta wings:

●     Tailless delta : Produces low drag and is structurally simple. Cannot be used in high wing loadings and requires a large wing area compared to aircraft wing.

●     Tailed delta : Another small delta shaped stabilizer at the back is used to optimize the plane for lift off. 

●       Canard Delta: A lifting canard delta offers  less shifting of the center of lift as the speed of the plane approaches the speed of sound.

Advantage:

●        Makes very less noise at supersonic speeds, good for stealth

●        It combines low relative wing thickness with a thick wing spar due to large root chord. This is especially helpful in reducing wave drag at supersonic speeds.

●        Low relative thickness gives high internal fuel volume due to large root chord.

●        With enough leading edge sweep, flow separation can increase lift by producing vortex lift.

●        Does not require a separate tail surface to be stable in pitch

Disadvantage:

●        Produces very high drag at subsonic speeds, to where really powerful engines are needed and a lot of fuel is used to make the plane take off.

●        There is more viscous drag due to the larger surface area (more surface area for wind to attach itself onto the wing), especially when compared to a high aspect ratio wing.

●        Complicated aero devices like fowler flaps are harder to integrate into the wing, due to it's thin and simple design. If integrated, the trailing edge of the wing will produce extreme pitching if deflected.

 

Future of delta wings:

Due to its simple design, delta wings have a lot of modifications that can be made of them. This gives them a lot of future prospects in many different types of planes. Here are some examples:

 

1.       Rafale planes: Rafale is a delta canard military roll combat aircraft. Compared to normal configuration, delta wings have 20% mor efficiency. Canards make the handling more efficient too, and this makes the maneuvering much easier.Currently in F3 Standard, it has improved air frames in this version. The F4 standard is in development, and is expected to launch by 2025.

2.       Gripen planes: Gripen has a delta wing and canard configuration as well. It's design gives it relaxed stability it's controls are electronic configuration fly-by-wire flight controls. It's currently running Gripen E model achieved supersonic speed in 2018, and is continued to be developed by Saab AB as of today.

3.       Eurofighter Typhoon: European Typhoon is an European fighter plane, with twin engines, delta canard configuration, and can perform different roles in combat. It is highly agile and designed to for maneuverability in dogfights. Unlike the other two, this does not classify as a stealth fighter. It's Tranche 4 version is set to be used by the German military, with an order of 38 Tranche 4 already placed by the German government.