Russia's National Research Center "Zhukovsky Institute" has patented a new fixed-geometry air intake design intended for future supersonic civilian aircraft. The utility model, registered as RU 245823 U1, was published by Rospatent on September 7, 2026, with the original application filed on June 4.
The Zhukovsky Institute is Russia's leading aerodynamics and flight research body, historically involved in developing Soviet and Russian aircraft including the Tupolev Tu-144, the country's only supersonic passenger jet to enter service. The new patent is aimed at a future successor to that aircraft.
How the design works
The intake is designed to improve engine efficiency and stability across different flight modes, particularly at supersonic speed. Unlike traditional intakes with variable geometry, the new design has no moving parts, which reduces weight and simplifies the powerplant.
Its main feature is a two-stage system for slowing supersonic airflow. The first stage takes the form of a rounded dihedral angle with a wedge angle of 4 to 6 degrees, while the second uses a more complex surface calculated according to the laws of spatial conical flow.
At supersonic speed, this geometry produces three shock waves at once: a flat oblique shock, a conical shock and a closing shock. According to the developers' calculations, this allows air to be compressed more effectively before entering the engine and improves the total pressure recovery coefficient compared with the previous single-stage design.
Shape and boundary layer control
The intake's entrance and throat have a teardrop-shaped cross-section with rounded corners. This shape improves aerodynamics and also makes it easier to fit the intake at the junction of the wing and fuselage, allowing a smooth transition to the engine's circular inlet. The air channel's length is between three and five times the diameter of the engine inlet.
A separate challenge addressed by the design is managing the boundary layer, which is especially critical for intakes mounted above the wing or fuselage. Such placement is being considered for future supersonic passenger aircraft because it can partially shield shock waves and reduce the sonic boom reaching the ground.
To address this, engineers built in a boundary layer control system consisting of a trimmed upper section at the intake entrance and a transverse suction slot in the lower part of the throat. According to the patent's authors, this should prevent airflow separation and provide the engine with the necessary surge margin.
What the institute says
The Zhukovsky Institute said the new scheme would allow the powerplant to maintain stable operation across the full range of flight modes, and that its main advantages would be most fully realized at supersonic speeds.
