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| Continuous Detonation Engines |
| Several types of engines that utilize detonation waves have been conceptualized, of which the pulsed detonation engine (PDE) has seen the most extensive development. Other types can be categorized as continuous detonation engines (CDEs). One specific CDE concept is known as the oblique detonation wave engine (ODWE), where the inlet and combustor make use of a fixed oblique shock that heats up the fuel/air mixture so it immediately detonates. This engine can operate at hypersonic speeds, but not at low supersonic speeds because the incoming flow must be sufficiently fast enough to create the oblique shock and additionally keep the detonation wave from propagating upstream and out of the engine inlet system. Another relatively unexplored concept (until recently) is the rotating detonation wave engine (RDWE). This engine uses an annulus placed perpendicular to an inlet and nozzle system whereby a detonation wave continuously travels around and detonates the incoming propellants to produce axial thrust. Research into these concepts, with emphasis on the RDWE, is currently in progress via LSAMP funding. A few pictures from the testing of the first RDWE are shown below, with more information to be presented at a conference in 2010. With careful timing of the ignition sequence, the engine was able to produce a rotating wave although only for a few rotations. |
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| Image of the first RDWE during beginning of testing where ignition sequencing is critical. |
Image of the first RDWE towards the end of a test where the burning is deflagration. |
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| The version currently being tested utilizes hydrogen and air/oxygen to initiate the detonation wave in the annular chamber. Smaller and lighter than its predecessor, this engine uses fuel/oxidizer premixing with some new injection approaches. The engine can also easily be converted to use various fuels and oxidizers because of its modular design, and is currently awaiting thrust stand testing. A video is shown below of some of the initial testing of the engine with different fuels. We have tried a few fuel combinations with a variety of mixture ratios along with a free or slightly blocked end. Some of these tests result in deflagration although some appear more promising. |
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| Image of the second RDWE during a hydrogen/oxygen test exhausting into atmospheric conditions. |
Video of initial testing of the second RDWE using different gas mixtures. |
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