Researchers developed a propulsion system that could pave the way for hypersonic flight, such as travel from New York to Los Angeles in less than 30 minutes. They developed a way to stabilize the detonation needed for hypersonic propulsion by creating a special hypersonic reaction chamber for jet engines.
There is an intensifying effort to develop robust propulsion systems for hypersonic and supersonic flight that would allow flight through the atmosphere at very high speeds and also allow efficient entry and exit from planetary atmospheres. Stabilizing a detonation — the most powerful form of intense reaction and energy release — has the potential to advance hypersonic propulsion and energy systems.
The system could allow for air travel at speeds of Mach 6 to 17, which is more than 4,600 to 13,000 miles per hour. The technology harnesses the power of an oblique detonation wave that was formed using an angled ramp inside the reaction chamber to create a detonation-inducing shock wave for propulsion. Unlike rotating detonation waves that spin, oblique detonation waves are stationary and stabilized.
The technology improves jet propulsion engine efficiency so that more power is generated while using less fuel than traditional propulsion engines, thus lightening the fuel load and reducing costs and emissions. In addition to faster air travel, the technology could also be used in rockets for space missions, making them lighter, travel farther, and burn more cleanly.
Detonation propulsion systems have been studied for more than half a century but had not been successful due to the chemical propellants used or the ways they were mixed. Previous work by the research team overcame this problem by carefully balancing the rate of the propellants hydrogen and oxygen released into the engine to create the first experimental evidence of a rotating detonation.
The short duration of the detonation, often occurring for only microseconds or milliseconds, makes them difficult to study and impractical for use. The researchers, however, were able to sustain the duration of a detonation wave for three seconds by creating a new hypersonic reaction chamber, known as a hypersonic high-enthalpy reaction (HyperREACT) facility. The facility contains a chamber with a 30-degree-angle ramp near the propellent mixing chamber that stabilizes the oblique detonation wave.
Next steps for the research are the addition of new diagnostics and measurement tools to gain a deeper understanding of the phenomena. The team will continue exploring more experimental configurations to determine in more detail the criteria with which an oblique detonation wave can be stabilized. If successful in advancing this technology, detonation-based hypersonic propulsion could be implemented into human atmospheric and space travel in the coming decades.