Will the Rotating Detonation Engines Enable Hypersonic Planes?
Disk rotating detonation engines could provide engines that are 10% more efficient, which could enable hypersonic planes. The USA, China, and Russia will be ramping up hypersonic weapon and hypersonic plane spending over ten billions per year each.
Combustion can be performed in two different modes (deﬂagration and detonation). Deﬂagration is usually treated as approximately isobaric combustion. For detonation, its propagating velocity can reach the order of kilometers per second.
Three kinds of detonation based engines are most studied. They are standing detonation engine (SDE), pulse detonation engine (PDE) and continuously rotating detonation engine (CRDE).
* Internal combustion engines are less than 25 percent efficient.
* best aero-derivative gas turbines, such as the H series turbines used for electric power generation, might break 40 percent.
* major challenge for a single-cycle heat engine of any type to achieve 50 percent.
* Gas turbine and steam combined cycles can approach 60 percent.
* With enough pre-compression and efficient components, an RDE (rotating detonation engine) gas turbine by itself might top 50 percent.
* A combined-cycle RDE plant could possibly reach 70 percent efficiency, a goal of current DOE research.
The promises of increased efficiency, simplicity, and high power density are driving the current research focus on rotating detonation engines (RDEs). An engine that uses detonation rather than deflagration could have some key advantages. If harnessed in a gas turbine or rocket, detonation could reduce the need for some expensive hardware, lighten engine weight and increase power output and efficiency.
There is work on annular flow disk rotating detonation engines and radial flow disk rotating detonation engines.