Recently, a WeChat account of China’s First Aviation Institute of the Aviation Industry revealed that an aircraft had started to use its own engine, and the outside world speculated that it should be a WS-20 turbocharged turbofan engine used on a Y-20 transporter. Y-20 finally has in its own real engine, and its airdrop and airdrop capabilities will be effectively enhanced.
The outside world noticed that the engine started with the term “engine nacelle”. The engine nacelle is basically a wing crane layout aircraft, and the wing crane layout aircraft are mostly passenger aircraft and transport aircraft. The First Aviation Institute is a development unit of Y-20, so it can be concluded that this time it should be Y-20 to be using WS-20 large bypass turbofan engine. Another strong proof is that before the replacement of the new engine, the technical staff solved the electromagnetic compatibility problem, and the investigation of the photoelectromagnetic interference took 4 days and 3 nights, which shows that the engine uses the full authority digital engine control system (FADEC).
According to military analyst Xiao Feizhu, the D-30KP-2/WS18 engine currently equipped with Y-20 uses a mechanical control system and does not need to consider electromagnetic compatibility issues. And FADEC collects the working state of the engine through sensors and uses a microprocessor to control the operation of the engine, and the electromagnetic compatibility needs to be considered accordingly.
The original design of Y-20 was based on the WS-20 large bypass turbofan engine, but the development progress of WS-20 did not keep up with the plane, so the Russian D-30KP-2 medium bypass turbofan engine was used first, and then it was replaced by China’s domestic model of D-30KP-2 – WS-18. The performance of the D-30KP-2/WS18 is significantly different from that of the WS-20 large bypass turbofan engine, which limits the performance of Y-20.
WS-20 engine adopts high and low-pressure turbine counter-rotating technology. The traditional turbofan engine rotates in the same direction as the high and low turbines. This design is relatively simple, but the disadvantage is that the engine shaft is longer and the weight increases and the aircraft structure weight also increases.
In addition, the rotation of the engine rotor in the same direction will produce a torque on the aircraft, affecting the aircraft handling and maneuverability. Therefore, the new generation of large bypass turbofan engines such as LEAP-1 and GENX all adopt the high and low turbine reverse design.
The turbine reverse design can reduce the engine shafting, reduce the weight of the engine, and thus reduce the weight of the aircraft structure. In addition, the turbine reverse rotation also helps to eliminate the torque from the engine rotor to the aircraft, improve aircraft handling and maneuverability, and China’s domestic and international aero-engine industry generally believes that turbine reverse rotation should be the future development direction of the engine.
Due to the high technical level and advanced system architecture, this laid a solid foundation for the WS-20 performance upgrade. According to relevant information, the WS-20 has plans to develop an improved thrust type, increasing the take-off thrust to more than 15 tons, so that the maximum take-off weight of Y-20 could be further improved, and its load/range performance will see a further step forward.