According to a report from the "War Zone" column of the US-based "The Drive" website, after more than three months, the sixth-generation aircraft developed by AVIC Shenyang Institute took to the skies again for test flights. The public finally got to see high-definition images of the Shenyang Institute's sixth-generation aircraft with impressive details and a unique perspective. For the first time, its side weapon bays were revealed, showcasing its cutting-edge aerodynamic layout with its unique lambda-shaped wings and two-dimensional vector nozzles. The network informally refers to Shenyang Institute's sixth-generation fighter as the "J-50".
So far, there is still no definitive conclusion on the aerodynamic configuration of Shenyang Institute's sixth-generation aircraft. However, with the appearance of the Lambda wings and the elimination of vertical tails, along with its relatively flat design, it can be temporarily named "Super Flat Tailless Aerodynamic Configuration". Compared to other aerodynamic layouts, the super flat tailless aerodynamic configuration has the following advantages. First, by eliminating the vertical tail, the highly integrated aerodynamic layout can significantly reduce the aircraft's all-around radar cross-section, enhancing its low observability and stronger omnidirectional stealth capability.
Secondly, the absence of tails eliminates resistance caused by multiple wing surfaces and adverse aerodynamic interference between wing surfaces, while the integration of the wing with the fuselage reduces the total wetted area, thereby improving the overall aerodynamic efficiency. Thirdly, after the elimination of the vertical tail, the weight of the airframe structure is simplified and reduced significantly.
The wing of Shenyang Institute's sixth-generation aircraft can be divided into inner and outer sections. On one hand, the inner wing section must meet the functional requirements of traditional fighter aircraft fuselages—meeting the loading needs of engines, weapons, fuel, avionics systems, etc. On the other hand, it also needs to provide certain lift-to-drag ratio characteristics or ensure longitudinal stability and match the longitudinal moment during cruise flight of the entire aircraft.
The outer wing section is the main component that achieves the aerodynamic characteristics of the entire aircraft. It requires the wing profile to have minimal shock wave drag in transonic and supersonic flight conditions, as well as good stall characteristics at low speeds with large angles of attack. This makes its design concept completely different from the inner wing section, which is also the fundamental reason for the emergence of full-moving wingtip rudders.
According to the latest leaked videos, Shenyang Institute's sixth-generation aircraft adopts a DSI intake duct, which was also given particular attention by the US "The Drive" website. The DSI intake duct has significant advantages in terms of reducing weight, drag, and radar cross-section for flying vehicles. Therefore, it is not surprising that Shenyang Institute adopted it. Additionally, one cannot overlook the fact that the bulge in the DSI intake duct blends seamlessly with the fuselage, which facilitates the integration of the airframe and propulsion system.
The exhaust system is one of the most significant sources of infrared radiation for fighters. The infrared radiation wavelength range is generally between 3 and 5 microns, and due to the high temperature of the engine, the intensity of infrared radiation in the rear region of the aircraft is greatly affected (mainly between 8 and 14 microns). This has become an important part of the infrared stealth design of the flying vehicle.
Through integrated design with the flying vehicle, measures such as using components to block the exhaust system can effectively reduce infrared radiation energy. These include cooling hot components, shielding the exhaust system with the aft fuselage, enhancing mixing of cold and hot airflow, and reducing the reflection of thermal radiation from the cold parts of the fuselage to the hot parts of the engine.
Research studies indicate that compared to traditional axisymmetric nozzles, two-dimensional nozzles offer better mixing effects, which are beneficial for both radar and infrared stealth. Therefore, both Chengdu Aircraft Industry Group's and Shenyang Aircraft Corporation's sixth-generation fighters adopt two-dimensional nozzle designs. However, the specific differences between the two lie in the nozzle shape. For example, Chengdu Aircraft's two-dimensional nozzle is a continuous arc, while Shenyang Aircraft's remains to be further disclosed.
The application of mechanical two-dimensional thrust vectoring nozzles on the F-119 engine by American manufacturers has gradually made this technology familiar to the public. However, it does have the disadvantage of significant thrust loss. With the steady improvement in China's aero-engine technology performance, it indicates that China has minimized the impact of the "significant thrust loss" associated with two-dimensional nozzles. Many people believe that China's sixth-generation aircraft should adopt axisymmetric nozzles. However, compared to two-dimensional nozzles, axisymmetric nozzles have obvious disadvantages, which is why China has only conducted validation installations on the J-10B aircraft, without entering actual equipment deployment.
Some netizens compared the sixth-generation aircraft of the Northern Institute with the J-15 series and J-35 carrier-based fighters, believing that the spacing between the front and rear landing gears of the three aircraft is basically consistent, and the length of the Northern Institute's sixth-generation aircraft is likely ≤ 20 meters. They believe that the Northern Institute's sixth-generation aircraft may be deployed on aircraft carriers in the future, and China's sixth-generation carrier-based aircraft could disrupt the future naval and aerial battlefield landscape.
The models targeted by the J-15 series and J-35 are respectively the F/A-18E/F and J-35B/C. Given that the U.S. Navy will announce its next-generation carrier-based aircraft later this year, the Chinese Navy also has a strong demand for sixth-generation carrier-based aircraft. Considering past development history and current equipment, it is most appropriate for the Northern Institute to undertake the research and development of the sixth-generation carrier-based aircraft. It can be foreseen that besides the land-based version, Shenyang Aircraft Corporation's sixth-generation aircraft will also include a carrier-based variant. In terms of air combat capabilities, Shenyang Aircraft Corporation's sixth-generation aircraft is likely to be more powerful than Chengdu Aircraft's sixth-generation aircraft.
Despite the U.S. making reluctant efforts to promote the narrative that "the U.S. leads China in the sixth-generation aircraft field," it cannot be denied that "China's fighter design and manufacturing capabilities have made incredible progress." Clearly, China has significantly narrowed the gap with the United States in military aviation industrial technology, and even China's top-tier fighter development has begun to lead the United States. Within the next 10 to 15 years, as China's two sixth-generation aircraft enter mass production and service phases, China's aviation industry will transition from being a "follower" to a "leader," potentially rewriting the rules of future naval and aerial warfare with its multiple sixth-generation aircraft.
Original source: https://www.toutiao.com/article/7490360425586934311/
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