X-59 supersonic aircraft
Everyone knows that NASA will build rockets, spacecraft, space probe and other spacecraft. But do you know that this institution has a "traditional craft", that is, to build aircraft or supersonics. This tradition starts with the X-1 aircraft designed in 1946. It is the world's first supersonic aircraft, , with a flight speed of 1,278 kilometers per hour. With a loud noise, humans exceeded the speed of sound for the first time and left the sound behind.
has always been the case, since supersonic aircraft will generate huge sonic booms when flying, so they can only fly in specific airspace. After 70 years, the X-Series has been updated to the X-59 model, and this generation of models may solve the noise problem.
The plane broke through the sound barrier, and the sound explosion instantly!
Why does "sonic boom" occur?
When any object disturbs the air, it will cause changes in the surrounding air pressure. This change is similar to the ripple in water. It will continuously spread outward at a certain speed, forming a barrier, which is also called a sound barrier.
In the air, the sound propagation speed is 344 meters per second. When an object moves in the air faster than the speed of sound propagation, it breaks through this barrier, and then generates a strong shock wave . Our ears will hear the "pop" explosion, which is the sonic boom.
During the flight of a supersonic aircraft, the shock wave generated by the nose will propagate in all directions and will also be superimposed with the shock wave generated in other parts of the aircraft. The end result is that we hear two huge sonic booms on the ground.
As long as the aircraft keeps flying at supersonic speed , a sonic boom will be generated continuously. People at different locations below the plane route will hear the sonic boom at different times. The sound often exceeds 130 decibels within the range affected by the sonic boom. Without protective measures, we hear noises greater than 120 decibels and will suffer permanent hearing damage. It is precisely because of this that supersonic aircraft are limited to their flight range.
X-59 How to fly quietly
How to reduce the impact of supersonic aircraft on the ground to the level of ordinary aircraft? This is a problem that has been difficult to overcome for decades. Fortunately, the advancement of computer-aided design technology has made this idea possible. The X-59 model is a test aircraft using silent supersonic technology. All designs of the
X-59 model are designed to control the position and intensity of shock waves, thereby reducing the sounds that can be heard on the ground and reducing interference to the ground.
In fact, it is impossible to completely eliminate the shock waves generated by supersonic flights. The goal is to allow the shock waves to be evenly distributed along the flight direction. In this way, the shock wave will not superimpose it to form a huge sonic boom, but will attenuate it alone, weakening the sound. The first consideration of the design of the
X-59 model is aerodynamic factors. The length of the fuselage is close to 30 meters, and the pointed nose occupies about one-third of the length. The cockpit does not have a windshield, and a HD display is used to provide the pilot with a field of view, also known as the "external vision system". The
test results show that this design can turn the loud sound of a sonic boom into a hammer-like sound. When the X-59 flew past at a speed of 1,400 kilometers per hour, all people on the ground could hear a slight "bang" sound, and the sound was almost close to the sound of someone closing the car door nearby.
However, the above research content is still in the theoretical stage. Testing of the X-59 model will not begin until early 2023. The test plan is divided into two stages: the first stage, first conducting detailed scientific tests in a specific area of , , California; the second stage, selecting several cities in the United States for actual test reaction research.
focuses on the second stage, because people's responses to noise vary greatly and are not as simple and clear as testing instruments. Finally, whether the noise of the X-59 model is within the public's acceptable range can only be revealed after collecting their actual feedback.
Supersonic Flight 2.0 era begins
If everything goes well, we will witness the second supersonic flight era begins by 2030. It also announced the end of the first era of supersonic flight.
The huge noise limits that once supersonic aircraft can only fly on routes in specific areas. Due to the high cost, airlines do not have enough motivation to research and improve such aircraft.
If the noise is improved, the situation of supersonic flight will be different and will inevitably become the preferred option for all long-haul routes. Next, let’s see if the X-59 model can achieve the expected results.
