Among the fifth-generation fighter jets, only the J-20 is a unique design, because it adopts a duck-style front wing design. Many people believe that the nose of the J-20 has a canard, which not only affects stealth, but also increases flight drag.

In the fifth-generation fighter of , only J20 is a unique design, because it adopts a duck-style front wing design. Many people believe that the J20 nose has the same potential as the canard wing , which not only affects stealth, but also increases flight drag.

But in fact, the duck-style front wing design is one of the biggest innovations and black technologies of the J-20.

What is the candle layout

fighter Generally speaking, there are three types of aerodynamic layout . Since Wright Brothers invented the first aircraft, designers usually design the horizontal and vertical tail wing of the aircraft behind the wing. This layout has been used to this day and is called a conventional aerodynamic layout.

Triple wing surface aerodynamic layout is a pair of front wings installed on the basis of conventional aerodynamic layout. This aerodynamic layout first appeared in the early 1960s. The -meter Gaoyang Design Bureau used the MiG-21 fighter to be transformed into an E-8 test machine, which is the three-wing surface aerodynamic layout.

Based on the conventional aerodynamic layout, move the horizontal tail wing behind the wing to the front of the wing. The appearance of the aircraft is very similar to a flying duck, so it is called a duck-style aerodynamic layout, and the front wing is also called a canard wing.

From World War II , Soviet designers discovered that the duck-type aerodynamic layout can achieve better handling efficiency with smaller wing surfaces - the canard and wing can generate lift at the same time, and the horizontal tail can generate negative lift when balancing the torque. In a large angle of attack flight state, the canard only needs to reduce lift to generate a head lowering torque, which effectively suppresses the occurrence of excessive head-raising of the aircraft.

In short, using a duck aerodynamic layout can improve the lift-drag ratio of the aircraft in a large angle of attack flight state and save engine thrust. Therefore, the duck aerodynamic layout is an aerodynamic layout that is very suitable for ultrasonic flight.

, but its control difficulty has also increased accordingly, and it requires the support of an advanced flight control system. Because of the high technical difficulty, the fighter jets that tried this type of design in the early stage were not very stable during flight. Therefore, , and many countries have basically adopted normal layouts. Until the 1960s, the American XB-70 Valkyrie bomber took the lead in achieving a breakthrough, proving that the duck-style front wing design has better manipulation, of course, the premise is that the technical level must meet the standards.

Only on the basis of the highly developed aviation technology and in-depth research on the vortex interference mechanism and experiencing the gradual progress from tailless, fixed can we fully master the duck-type layout aircraft.

J-20 candle wings are special

J-20 candle wings are not ordinary candle wings, but lift body side wing duck-style layout. In addition to the medium and low altitude maneuverability of modern advanced fighters, the fifth-generation fighter must also have supersonic cruise capabilities and unconventional maneuverability such as stalls; at the same time, stealth characteristics are also a factor that needs to be considered. Therefore, its aerodynamic layout should reduce its supersonic resistance as much as possible while meeting the external stealth constraints, improve the maximum lift characteristics and stability and controllability at large angles of attack, and take into account the sub-transonic lift resistance characteristics. The development of the duck-style layout of the side strip of the lift body has solved three technical keys: one is the aerodynamic coupling problem between the canard and the medium sweep angle and the medium aspect ratio wing; the second is the coupling problem between the canard, the front strip of the wing and the wing body vortex; the third is the gains and losses of the wing body lift body using the duck-style layout.

After many studies, Chinese researchers found that using canard wings and front strips at the same time not only maintains the lifting effect when using the two lifting devices separately, but also can obtain a higher lift coefficient. This shows that some advantageous coupling effect is created between the canard, the front bar and the wing. The lift body layout with the wing body fusion can use the fuselage to generate lift, and increase the internal volume and improve the stealth characteristics at the cost of less resistance.

When using candle wings, the J-20 flips the candle wings at 90 degrees, and the vertical tail wings have a large angle flip. No fighter can do it at present.The F-22 and F-35, which are currently in service in the US military, have the vertical tail wings that deflect downward when landing, and the horizontal tail wings are at the same time, so as to achieve the deceleration effect; however, their vertical tail wings are all conventional rudder designs, with limited deflection angles and generally cannot exceed 40 degrees, and the lower deflection angle of the horizontal tail wing is also limited. The aerodynamic deceleration effect is far less than that of the 90-degree flip canard.

This is China's original design. The purpose is to make up for our engine disadvantages through a brand new aerodynamic layout and find the optimization of the above design points. Therefore, the J-20 adopts this aerodynamic layout, and the canard is only an integral part of this aerodynamic layout.

American fighter jets will also use canard wings in the future

. The reason why friends have questioned that the J-20 canard wings have affected their stealth performance is because the Americans themselves have eliminated the canard wings. They believe that the layout of canard wings greatly affects the stealth performance of the aircraft, so they look down on the canard design of the fighter aircraft very much. The arrival of the stealth era has made the stealth capability of a fighter an important criterion for evaluating the excellence of a fighter. The Americans even said this: "The canard is best installed on an enemy's plane."

But in fact, at the beginning of design, the first thing the J-20 considers was stealth performance, large range, highlighting the maneuverability of supersonic , highly informatized, omnidirectional threat perception and enhanced multi-spectrum stealth ability, can be said to be the characteristics and advantages of the J-20, which is also the reason why the lift body side wing duck-like layout is adopted.

In fact, the most commendable thing about the fifth-generation fighter of the United States is never the aerodynamic layout. Americans themselves think that their conventional aerodynamic layout is no longer in line with the times. The reason why F22 and F23 use tail wings is because for decades, American aircraft have all tail wing designs. He has rich experience in this area and has a deep understanding. This is his strength. The United States must choose its strengths to develop. Usually, you don’t need to install a candle with a tail wing, and you don’t need to install a tail wing with a candle. This is a matter of choosing one of two, and the United States must choose its own expertise.

The reason why the United States complains about canard wings is because it has weak technical accumulation of canard wings, but the United States' own sixth-generation fighter will also adopt the canard wing design. The concept map of the sixth-generation fighter released by the United States adopts a canard layout and full-move tail design that is very similar to the J-20, which can be said to have slapped some people in the face.

In summary, the aerodynamic design of the J-20 is a collection of the hard work of countless military workers, tens of thousands of wind tunnel tests and simulations, thousands of actual aircraft tests, and the finest of the crystallization from the J9 designed in 1965, representing the advanced level of the world's fighter aerodynamic design.

, supported by advanced omnidirectional sensors and systematic combat data links, cooperates with the world's best power performance long-range air-to-air missile 9, and with excellent high-speed performance, the J-20 is likely to be the world's most capable fighter with the strongest capabilities of BVR in the world, and its excellent aerodynamic design is of great significance.