The J-20 is the first fifth-generation stealth fighter independently developed by the mainland, with excellent stealth performance and strong situational awareness, and its appearance breaks the US military's false claim that China will not have a stealth fighter before 2020. Since it entered service in 2017, the number of J-20 has been close to 300, and it is no exaggeration to say that the J-20 is already the world's largest number of heavy stealth fighters in service. However, in the hearts of the majority of military fans, the current J-20 is not a perfect product, mainly because the J-20 is not equipped with a special turbofan-15 engine, and the flight performance has been limited to a certain extent. The good news is that the latest J-20 has been replaced with two turbofan-15s, and the strongest J-20 has arrived.
Recently, some netizens took pictures of a new J-20 flight test flight that had just left the factory, this J-20 was yellow all over, and it was obviously not coated with stealth paint. The author noticed that the shape and color of the tail nozzle of the new engine of the J-20 are quite different from the turbofan-10C engine equipped with the current J-20, and it is obvious that the new batch of mass-produced J-20 has begun to be replaced with a new engine. Judging from the exposed pictures, the color of the exposed tail nozzle of this new engine is all black, while the tail nozzle of the turbofan-10C engine has two colors: silver and black. Therefore, we have reason to believe that the J-15B, equipped with turbofan-20B, has already achieved mass production and will quickly equip the PLA Air Force units.
Close-up of the turbofan-10C engine
At present, the J-20A equipped with turbofan-10C engine already has supersonic cruise capability, and the super-maneuverability performance is also good, and it is already capable of confronting advanced stealth fighters from countries around the mainland. However, after all, the turbofan-10C is a third-generation engine improved on the basis of the turbofan-10, and there is still a very obvious gap with the fourth-generation F-119 and F-135 engines in the United States in terms of thrust and thrust-to-weight ratio. For example, the maximum thrust of the American F-119 and F-135 engines is 17 tons and 18 tons respectively, while the maximum thrust of the turbofan-10C engine is 14.5 tons, so compared with the American F-22 fighter, the thrust of the J-20A engine is obviously at a disadvantage.
According to public information, the turbofan-15 engine has a maximum thrust of 18.5 tons, a thrust-to-weight ratio of more than 10, and adopts a dual-redundancy full-authority digital electronic control system and a three-way vector tail nozzle, which has obvious advantages over the turbofan-10C in terms of thrust, fuel consumption and electronic control system. After replacing the turbofan-15 engine, the J-20B supersonic cruise speed can reach Mach 1.8 and the maximum flight speed is Mach 2.2, while the supersonic cruise speed of the F-22 fighter is only Mach 1.5, which means that the J-20B is better than the F-22 in flight speed.
In addition to the increase in supersonic cruising speed, the J-20B's super-maneuverability and payload will be improved to a certain extent, and the combat radius is expected to exceed 2,000 kilometers, and the long-distance combat capability will be further improved.
In the following test flight picture, we can see that the fuselage behind the J-20B cockpit has been heightened, which makes the lines behind the J-20 cockpit more smooth and beautiful. It is no wonder that many netizens have reported that the new J-20B is much better looking than the J-20A.
In fact, the original intention of this heightened fuselage is not for aesthetics, but to reduce drag during flight. According to the results of relevant papers, during the cruise of the fighter, a strong shock wave will be generated at the forward windward parts such as the cockpit, and the pressure will gradually recover through the expansion wave after the shock wave, and there will be a reverse pressure gradient area behind the shock wave, which will lead to an increase in the resistance of the whole aircraft. Researchers can optimize the inverse pressure gradient by appropriately heightening the cockpit ridge curve. In this way, the fighter will reduce the transonic flight resistance by about 10%, and the decrease in flight resistance has a positive significance for the fighter's fuel consumption, range and combat radius.
It can be seen that the J-20B has been optimized to the greatest extent in terms of shape and power, and the engine problems that have plagued the J-20 for a long time no longer exist. At present, the turbofan-15 has reached the level of the American F-119 engine, and thanks to the light empty weight and excellent aerodynamic layout, the J-20B's supersonic cruise capability and super-maneuverability are expected to surpass the American F-22 fighter. In addition to the upgrade of the power system, the on-board electronic system of the J-20B has also been greatly upgraded, and we have reason to believe that the situational awareness of the J-20B will continue to lead the world.
Therefore, to sum up, the J-20B has no obvious shortcomings, and has the ability to become the world's strongest stealth fighter, which will help the Chinese Air Force firmly grasp the future air supremacy.