Image source: topwar.ru
The French aerospace research Center ONERA is working within the framework of the Superman project, which creates a fighter concept capable of combining maneuverability and stealth, like the Su-57.
As indicated in the Air Cosmos publication, the corresponding mock-up tests are carried out in the ONERA wind tunnel in Modan. During testing, the developer is trying to find the optimal balance between the three main characteristics of the fighter – maneuverability, stealth and speed.
- explained in ONERA.
Previously, designers could not find the optimal balance. For example, although the inconspicuous F-22 can be called maneuverable, but to an insufficient extent, since it has vector thrust only on two axes (which is caused by the requirements for stealth from the rear side of the fuselage), while the Su-35, which is not "stealth", is on three.
In ONERA, in search of an optimal solution, the Russian experience was used in the development of a new design:
Image source: topwar.ru
To achieve this goal, the developers used the Levcon technical solution. This is the name of an additional inclined plane attached to the base of the wing in front, which increases lift at low speeds, provides a large angle of attack and allows you to quickly exit the stall. At the moment, Levcon is used on two types of aircraft – the Russian Su-57 and the Indian Tejas.
- the French designers declare.
According to them, the example of the Su-57 shows that when creating the desired angle of attack, you can control the relative position of the air intake and Levcon. The concept created by ONERA is called a "technological feat" by the developers:
At the moment, the model is blown through the wind tunnel only at low speeds for a fighter (200 km / h). Over time, it will be equipped with an engine and a set of thrusting surfaces, which will increase the speed.
- developers explain.
The shape of the aerodynamic profile, when viewed from above, is very similar to the design of the Su-57. Its characteristic angles allow you to avoid stalling. When changing the angle of attack in cruising mode, the pitch moment of the aircraft is zero. For the Superman model, this formula works up to a speed of Mach 0.85.
During the work, the designers are trying to link Levcon with vortex flows that create lift for the aircraft.
- developers explain.
As an example, they cite steep cabring: the aircraft should lose speed during a sharp climb, but Levcon, manipulating vortex flows, allows [lightning] to return to the position with the nose down to restore speed.
- summed up in the French edition.
