Simple, fuel-efficient rocket engine could enable cheaper, lighter spacecraft

Sending NASA's Space Shuttle into orbit required more than 3.5 million pounds of fuel, which is about 15 times heavier than a blue whale.

But a new type of engine -- called a rotating detonation engine -- promises to make rockets not only more fuel-efficient but also more lightweight and less complicated to construct.

"I tried to recast our results by looking at pattern formations instead of asking an engineering question -- such as how to get the highest performing engine -- and then boom, it turned out that it works."

A conventional rocket engine works by burning propellant and then pushing it out of the back of the engine to create thrust.

"A rotating detonation engine takes a different approach to how it combusts propellant," Koch said.

But in a rotating detonation engine, the shock wave naturally does everything without needing additional help from engine parts.

"The combustion-driven shocks naturally compress the flow as they travel around the combustion chamber," Koch said.

It's so violent."

To try to be able to describe how these engines work, the researchers first developed an experimental rotating detonation engine where they could control different parameters, such as the size of the gap between the cylinders.

Each experiment took only 0.5 seconds to complete, but the researchers recorded these experiments at 240,000 frames per second so they could see what was happening in slow motion.

From there, the researchers developed a mathematical model to mimic what they saw in the videos.

"This is the only model in the literature currently capable of describing the diverse and complex dynamics of these rotating detonation engines that we observe in experiments," said co-author J.