BAE Systems pays more attention to detail design and highlights stealth performance in its development scheme. Compared with Raven, Raytheon Verification Machine adopts triangular air inlet, and the obviously raised air inlet is somewhat abrupt, in order to effectively ensure the air flow required by the power plant. What is different is that the machine adopts the beaver tail exhaust device, which completely wraps the engine tail nozzle in the machine body to achieve the purpose of reducing radar and infrared signals at the same time. In this way, the machine naturally and smoothly transits from the rhombic section of the front fuselage to the straight section of the rear fuselage, which better meets the requirements of low detectability on the premise of ensuring aerodynamic performance. Raytheon verification machine will adopt static unstable flight control system. Previously, BAE Systems has successfully solved many key problems faced by digital fly-by-wire flight control system through Raven and Hetty verifiers, which can better realize the coupling control of a large number of control surfaces, thus ensuring that the full-scale verifier has static and unstable flight characteristics and can fly autonomously and reliably under various conditions.
The details of the design of the control wing of Raytheon Verification Machine can't be seen from the rough imagination, but the criss-crossing "turtle pattern" on the wing seems to reveal that BAE Systems will try to adopt some more mature pneumatic control technologies. On the raven verification machine tested before, there are only four control surfaces at the trailing edge of the wing, but the retractable "embedded surfaces" are carefully designed on the upper and lower surfaces of the wing, which can realize differentiation according to control instructions and provide yaw moment. At the same time, in the process of taking off and landing, the open landing gear door can play the role of vertical tail, which meets the requirements of course stability in low-speed flight.
In the imaginary picture of Raytheon verification machine, a pair of black round holes appear above the wings on both sides, and even obvious smoke traces are drawn. Therefore, it is possible for BAE system to adopt key technologies such as fluid thrust vector (FTV) and cycle control (CC) on full-scale verification machine. In this way, Raytheon verification machine can effectively control the main flow and secondary flow on both sides of the fuselage, generate vector thrust along the surface of the fuselage, and thus obtain pitch and roll control forces. At the same time, the aircraft can also use the high-pressure air from the trailing edge of the wing to achieve the aerodynamic effect of flap lift, thus further enhancing the stealth performance without flaps. In the overall design, BAE Systems has repeatedly stressed that Raytheon unmanned combat aircraft will have the ability to deliver weapons to another continent. This shows that UCAV has intercontinental voyage and excellent endurance, which not only puts forward higher requirements for overall size, but also has many considerations for the performance of power plant. In this regard, as one of the development contractors involved in this project, rolls royce Company began to consider the engines of UAV and UCAV for FOAS as early as the beginning of 2002, and put forward a development idea: if the investment can be obtained, a special new engine will be developed, otherwise, a compromise scheme can only be maintained, that is, the propulsion system design must be suitable for the latest models such as EJ200 or Adoul MK95 1 engine.
In fact, as early as 2005, BAE Systems Company considered EJ200 turbofan engine as a candidate power plant at the initial stage of UCAV scheme design, and its maximum thrust reached 60kN without afterburner. However, EJ200 engine, as the power device of European fighter typhoon, mainly highlights the air superiority performance in thermal cycle and working parameters, and whether it is suitable for unmanned combat aircraft undertaking ground attack tasks needs more comprehensive research.
BAE Systems Company made a detailed analysis of the effectiveness of EJ200 engine, and thought that its structural size was a little too large, which was not suitable for the overall configuration of the verification machine, especially the demand for airflow might lead to an increase in air intake. In this way, the overall size of the verification machine must be increased by more than 10% or the geometric configuration must be changed, which may lead to a 20% increase in radar reflection cross-sectional area and a great decrease in stealth performance. Based on this conclusion, BAE Systems Company considered choosing a turbofan engine that is more suitable for flight verification, and rolls royce Company suggested adopting the MK95 1 engine of Adoul series. June 5438+October 2006 10, Dassault officially ordered two Adoul MK95 1 engines as the power devices of the neuron verification machine. The first one was delivered for ground test in the summer of 2007, and the second one will be delivered as a backup at the end of 2065 438+ 10 to prepare for the test flight.
Compared with the neuron verification machine, Raytheon verification machine is similar in size and weight, and all indexes of Adoul MK95 1 engine can meet the design performance requirements, which is also in line with the principle of using commercial products as much as possible in the verification scheme. Therefore, BAE Systems decided to use this type of engine as the power device of Raytheon verification machine. According to rolls royce, this engine is a derivative of Adoul MK87 1 engine. The main improvements include: the new fan design provides greater thrust, and the turbine components are made of better materials to improve durability, which not only increases the thrust by 8%, but also reduces the life cycle cost. At the same time, the engine adopts full authority digital engine regulation (FADEC), which can provide anti-surge, automatic control and recovery. From the technical level of SUAVE, one of Raytheon's core tasks is to evaluate whether UCAV's autonomous combat capability can meet the expected battlefield use requirements. For this reason, BAE Systems is designing the autonomous control system of Raytheon Verification Machine with the help of the progress made in system intelligence, with the aim of providing a high level of autonomy and effectively improving operational efficiency.
This system can autonomously control taxiing, take-off and navigation along the search airspace, and at the same time, it can respond to any threats or other emergencies in time. Then, it will determine the best route around the search area, lock the target, and then use the sensor system to transmit a series of images and observations and feed them back to the operator to determine that this is the target of the expected attack. Finally, once the plane is authorized, it will attack the target on its own, then return to the base, land and taxi along the scheduled route.
In UCAV, the British Ministry of Defence still tends to keep the man-in-the-loop control mode to ensure that the operator has the right to make key task decisions, such as confirming enemy targets and launching weapons attacks. The operator can control from the ground station or give instructions from the back seat of the two-seater fighter. Therefore, since 2006, the British Ministry of Defence has implemented the "Autonomous Command and Control" project according to the SUAVE plan, which verified the feasibility of controlling multiple UCAV on a jet fighter on the ground and in the air, but this technology needs to be further matured before it can be put into use. Based on long-term accumulated experience, BAE Systems will adopt an advanced and highly flexible open system structure in the airborne mission system of Raytheon Verification Machine. In the verification stage, the aircraft will be equipped with traditional photoelectric and radar sensors as the basic airborne detection equipment, and the conformal radar being developed by BAE Systems Company may be adopted for a long time. In this way, the Raytheon verification machine can not only meet the current mission concept of deep attack, but also perform long-range reconnaissance and surveillance tasks as needed. Undoubtedly, as an attack platform specially used to verify low-altitude penetration tasks, the verification machine will adopt the design of two built-in weapon cabins, so as to be able to carry ground attack weapons and maintain strong survivability.
BAE Systems only indicated that it would arrange a Raytheon verification machine to simulate the weapon delivery test, and has not planned to implement the weapon delivery test. Therefore, it is still unknown what specific types of weapons UCAV will carry in the future. However, according to relevant reports, British industry is conducting a series of detonation tests on directed energy warheads. The Ministry of National Defense has decided to introduce the directed energy weapon system before 20 1 1, and initially plans to equip this warhead with a storm precursor missile. It is speculated that British UCAV may use high-power laser or microwave weapons as the choice of attack weapons. It is reported that BAE Systems is also considering applying the Image Acquisition and Development (ICE) system in the Raytheon project to undertake aerial surveillance and reconnaissance tasks. The ICE system consists of two wide-angle cameras, and a narrow-angle camera can be installed in the turret, both of which have infrared imaging capabilities. ICE system has the capability of airborne storage and operation, which can be used for post-flight analysis, and can also relay compressed images to the ground through a low-frequency data link, or realize intercontinental transmission through satellites. The ICE system can be organically integrated with the control system of the verifier, which provides greater autonomy and flexibility and can produce complete and accurate plane scenes. The system successfully realizes the autonomous target search of Hetty UAV.