What are the advantages and disadvantages of a forward swept wing aircraft?

The forward-swept wing has a unique advantage in aerodynamics, with a high lift-to-drag ratio; It can ensure a better connection between the wing and the fuselage; Conducive to take-off and landing; Moreover, its greatest benefit is maneuverability, and this advantage is most pronounced in the subsonic range. If the forward-swept wing layout is combined with the thrust vectoring control system, the aircraft is even more powerful in air combat. Of course, the forward-swept wing isn't perfect.

For example, its technology is complex, the related technical requirements for it are relatively high, the strength of pneumatic components is large, and the problem of wingtip tremor cannot be completely solved so far. So at the moment there are still very few fighters with this layout. However, it represents a kind of aircraft development direction.

Russian Su-47 "Golden Eagle" forward-swept wing fighter The aircraft uses forward-swept wings to improve controllability when flying at low speeds and improve aerodynamics in all flight conditions. Adopting the aerodynamic layout and thrust vector control technology of three-wing surface, double vertical tail, front and rear full-motion control surfaces, the fuselage is widely made of composite materials, which has good supersonic cruise, super-maneuverability and stealth capabilities. Two AL-41F thrust vectoring turbofan engines are installed, each with a maximum afterburner thrust of 175 kN and a thrust-to-weight ratio of about 10.

The length of the aircraft, the height of the aircraft, the wingspan meters, the maximum take-off weight of 34 tons, the maximum speed of Mach, the ceiling of 18,000 meters, the maximum range of 3,300 kilometers. The on-board equipment includes the most advanced digital multi-channel equipment made in Russia, an automated integrated command system, an integrated navigation system, and a new generation of crew life support and ejection integrated systems. Equipped with advanced radar, LiDAR and rearview radar with TV, thermal infrared, and laser equipment are used.

The cabin can carry ultra-long-range air-to-air missiles and long-range air-to-air missiles, including the KS-172 missile, a two-stage missile that can reach hypersonic speeds and is equipped with a composite guidance system capable of striking air targets up to 400 kilometers away. It can also carry an air-to-ground assault**, while retaining the 30mm cannon. "Golden Eagle" Su--47 (Su-47) Basic data:

Length: m Wingspan: m Full take-off weight:

24 tons Max speed: Mach Max overload: 27g over Su-9 Construction materials:

13% of the weight is made of composite materials, aluminum alloys and titanium alloys.

The aerodynamic characteristics of the forward-swept wing aircraft are superior, and there are many advantages including high critical Mach number, low wave resistance and overcoming wingtip stall, but the problem of torsion is also an obstacle to the widespread practical application of the forward-swept wing aircraft, so composite materials must be used

Trouble, thanks!

The swept wing is mainly used for high-speed aircraft, which effectively reduces drag at high subsonic and supersonic speeds. The front wing can reduce the turbulence of the tail wing and improve the stall characteristics, but it is structurally demanding. The swept wing and the swept wing use the same principle but use the completely opposite method to delay the shock wave, so that the aircraft can enter the supersonic speed better and faster, so the swept wing can completely achieve supersonic cruise, but the airflow of the swept wing is separated at the wing tip, and the swept wing is at the wing root, so the wing of the swept wing is easy to break at high speed, and the best solution is to use composite wings, the Russian Su-47 and the American X-29 technical verification aircraft basically solve this problem, The canard wing is used to solve the lift trim problem and improve the maneuverability, but the combined stealth performance of the canard wing and the forward sweep wing is too poor.

So the vast majority of current aircraft are swept wing.

The forward-swept wing has all the advantages of the swept wing, but also has the advantages that the swept wing does not have, and the forward-swept wing can effectively prevent the stall caused by the aircraft when doing aerobatic maneuvers, which improves the safety factor. Moreover, the lift of the forward-swept wing is greater than that of the back-swept wing of the same area. The reflection interface to the radar is smaller, and the maneuverability is more flexible.

The X29 was the world's first swept wing aircraft, followed by the Su-47

1. The forward-swept wing increases the lift by more than 30 100 compared to the swept wing of the same area.

2. When the speed of the aircraft exceeds the speed of sound, the forward-swept wing is more flexible.

3. Forward-swept wings, faster than backswept wings, it is easier to break through the sound barrier.

<> "What exactly is an airplane's swept wing?"

<> "What exactly is an airplane's swept wing?" Just as birds need wings to soar into the blue sky, fitting an airplane with a pair of useful "wings" has always been a relentless goal. Early airplanes generally had straight wings, but as flight speed increased, the aircraft would disintegrate and crash during high-speed dives.

Later, scientists discovered that when the flight speed is close to the speed of sound, the plane encounters extreme drag, as if hitting an invisible "stone wall". At this time, the plane either struggled to increase its speed, or could not withstand the huge impact and was shattered. This invisible "stone wall" is also called a shock wave.

The front of the shock wave is straight exactly at the speed of sound. As the velocity increases, the front of the shock wave becomes conical, the tilt angle of the cone increases with velocity, and the air behind the front returns to subsonic.

If the straight wing sweeps back like a swallow's wing, "ducking" behind the shock front caused by the nose, the shock drag caused by the wing itself can be avoided. The German Adolf Bussmann proposed the swept wing in the 30s of the last century, but it did not attract the attention of the people at that time. The swept wing of an airplane is a wing with the front and trailing edges extending backwards and is tapered.

The index that characterizes the degree of wing sweep is the sweep angle, which is the angle between the leading edge of the wing and the horizontal line. The so-called swept wing aircraft refers to aircraft with a wing sweep angle of more than 25 degrees. It is no exaggeration to say that the appearance of the swept wing was a major change in the shape of the wing, which had a great impact on the development of the aircraft.

The high subsonic and supersonic aircraft we see today invariably use swept wings or swept delta wings modified by them.

In fact, swept wings are beneficial for both subsonic and supersonic flights. For subsonic flying Hongsen hungry travelers, the swept wing can increase the flight Mach number corresponding to drag divergence; For supersonic flight, the swept wing reduces shock drag. The effect of the swept wing to avoid the shock wave drag caused by the wing itself is already hidden when the speed of the aircraft has not yet reached supersonic speed.

The wing generates lift by accelerating the upper surface airflow to create a velocity difference between the upper and lower surface airflow, which in turn results in a pressure difference.

At high subsonic speeds, the velocity of the airflow on the upper surface of the wing can exceed the speed of sound. With a swept wing, the oncoming airflow is split into components perpendicular to the leading edge of the wing (normal component) and components parallel to the leading edge of the wing (span component) according to the sweep angle, with the normal component generating lift and the spread component not excavating lift. When the sweep angle is equal to zero, the normal component and the heading airflow are equal; The larger the sweep angle, the smaller the normal component.

That is, by using a suitable sweep angle, the airflow on the upper surface of the wing of a high subsonic aircraft can be reduced below the speed of sound in the normal direction, avoiding shock drag. Swept wings are widely used in transonic (in the multi-sonic range) and high subsonic aircraft, such as the J-6 fighter, various Boeing spring limbs, and Airbus airliners.

There are many advantages, such as reduced drag, increased speed, better handling, the disadvantage is that the low-speed performance is not good, in fact, if the jet does not use rectangular wings, only small propeller aircraft use, these aircraft do not need high speed, and the cost is also lower.

Excellent: The swept wing reduces the relative airspeed and delays shock wave generation. The swept wing produces an oblique shock wave with low wave resistance.

Missing: The relative airspeed is small at low speed, and it is easy to stall. Resulting in poor low-speed performance, the take-off and landing speed is too large. The wingtips are prone to stalling and induce high drag.

Therefore, the high-speed ones are swept back, and the low-speed ones are straight. Later airfoil and variable-swept wing technologies were designed to balance the two.