General Electric pulse detonation turbofan

[Matej]

On the subject of PDEs - pulse detonation engines - General Electric has just been assigned a US patent for a turbofan that uses a rotating pulse-detonation system, rather than low- and high-pressure turbines, to drive the fan and compressor. Basically, each turbine stage is replaced by a radial array of raked and angled pulse-detonation tubes.

http://www.google.com/patents?id=OJynAAAAEBAJ&dq=7,328,570

 

[blackkite]

Is it applied for manned aircraft?

 

[Matej]

I am not sure if that kind of sorting can be applied. What makes the engine better suitable to manned and what to unmanned applications? Isn't much important the thrust, weight, dimensions, fuel consumption and so rather than used technology?

 

[PNorwood]

If you could eliminate the turbine from the equation that does increase exhaust velocity and overall engine efficiency. It would also allow somewhat higher mach numbers to be achieved.

 

[blackkite]

I understand that PDWE's noise and vibration is too large for manned aircraft.

 

[Sundog]

I understand that PDWE's noise and vibration is too large for manned aircraft.

That's true for a pure PDWE, as designed and tested, so far. What they're proposing is not a pure PDWE. Most of that noise will be "buried" within the engine and mitigated by the PDWE turbine blades. Until it's built and tested, I don;t think we'll know how it compares to a conventional turbofan/turbojet.

 

[quellish]

I understand that PDWE's noise and vibration is too large for manned aircraft.

This is not entirely true for PDEs. There are solutions out there for multi chamber PDEs that solve this problem. For example, with multiple chambers they can be operated out of phase, which can be done to minimize the effects.

There's this too:
http://www.google.com/patents/about?id=Nux2AAAAEBAJ&dq=pulse+detonation

 

[mz]

IIRC there was a large story on both PWR and GE attempts on pulse detonation engines, especially relating to use in place of "burner cans" on jets.
There's a *very rough* analogy for thinking about this:
Think of a piston engine that has some compression ratio. Then you can add a turbocharger into it to increase the compression ratio. Take away now the piston engine and leave just the turbo - now you have a turbine engine that has a lower compression ratio than the piston engine had but better power to weight.
Keep the jet/turbo but substitute a compression engine, PDE, for the piston engine. Now you have a PDE-jet that has a high compression ratio and high efficiency and high thrust to weight.