The sound of a new supersonic aircraft compared with the slam of the door
New supersonic passenger jet will be a thousand times quieter.
Prospective passenger supersonic aircraft, developed by the American company Lockheed Martin for the project QueSST will be about a thousand times quieter than comparable size conventional aircraft. As reported by Flightglobal, said the head of breakthrough projects in the Skunk Works division of Charles chase.
According to him, the shock wave formed by the new aircraft will be seen by observers on earth as a “dull thump in a car door a few houses down the street.”
The ultimate goal of the project QueSST, within which is created a new aircraft, is the development of quiet supersonic aircraft. This plane will allow supersonic flight over populated land is prohibited today. It is assumed that the shock wave from such an aircraft will not deliver serious concern to the inhabitants on earth. The aeronautical authorities may allow supersonic flights over populated part of the land, if you perceive the noise of passenger aircraft will not exceed 75 decibels.
According to chase, to achieve a significant reduction of the intensity of the sonic boom of a new supersonic aircraft will fail due to a significant lengthening of the fuselage, to smooth the differences between the protruding elements and the use of additional aerodynamic elements.
In particular, the prototype of the new aircraft will receive canards and additional horizontal tail on the vertical tail fin. These elements will “break” the shock wave from the fuselage.
Other details about the new technical solutions developed by the project QueSST, were not disclosed. In flight at supersonic speed, the plane forms a plurality of shock waves of pressure surges. In flight the shock wave is usually produced at the tip of the nose cone on the front and rear edges of the wing, on the leading edges of the tail, in the areas of swirlers flow and on the edges of the air intakes.
Observers on the ground as a loud popping noise perceived shock N-waves. Such waves on the chart resemble the letter N Latin alphabet due to the sharp increase in pressure at the wave front, with a sharp pressure drop and subsequent normalization. New aerodynamic design of the aircraft will generate S-waves smooth and not as significant as N-wave pressure drop. It is assumed that S-waves will be perceived by observers as cotton in a car door.
It is expected that in 2018, Lockheed Martin will begin Assembly of the first prototype of a supersonic passenger plane. In 2019, NASA plans to conduct a critical review of the draft of the aircraft, and in 2020 — for the first time to lift the machine into the air. According to the plans of NASA, the first flight will be conducted additional flight tests of new aircraft, and in 2021, the experts will start the first evaluation flights of QueSST.
Promising “quiet” supersonic aircraft will be performed single engine. Its length is 28,7 meters. He will get the airframe, the fuselage and wing which resemble an inverted plane. On QueSST will install conventional vertical fin and horizontal rudders for maneuvering at low-speed flight. At the top of the keel will be installed a small T-tail. Long nose will significantly limit visibility from the cab. Visual guidance during takeoff and landing, the pilots will produce images obtained from the nose camera of high definition.