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.
According to the patent, the first ring of PDE tubes (58) is fired first to start the booster compressor (28) turning. Once the booster is up to speed it provides compressed air to the remaining PDE rings (59), which then fire up to drive the fan (20).
As a PDE ring turns, each tube sequentially passes first a port (50) allowing air into the tube, then a fuel injector (52), then the igniter (54), which initiates a supersonic detonation wave (66) to power the ring's rotation.
Comments (5)
Could this system not be adapted to rotary wing flight? A non-torque reaction inducing rotor, as per the Fairy Rotordyne? It would give the high rotor torque thrust values required of modern six to eight blade rotors.
Posted by Ian Jones | March 5, 2008 8:51 AM
Posted on March 5, 2008 08:51
Hellishly noisy, I suspect - like the Rotodyne
Posted by The Woracle | March 5, 2008 3:12 PM
Posted on March 5, 2008 15:12
It is nearly 50 years since anyone heard a Rotodyne and with '60s and 70's jets not yet heard at that time, I am wondering just how loud it really was. Is there some clear data and can anyone who did hear it give an idea of the problem?
And was any effort made to quieten it during its short life
Posted by John Aislabie | March 8, 2008 1:40 AM
Posted on March 8, 2008 01:40
Good question. My understanding was they had made significant progress in reducing tipjet noise when the Rotodyne was cancelled (for political and not technical reasons).
But Groen is wrestling with tipjet noise on its Heliplane high-speed gyroplane for DARPA, so it's clearly a difficult problem.
Posted by The Woracle | March 8, 2008 2:09 AM
Posted on March 8, 2008 02:09
It seems pretty obvious to me, but I'm not in the "biz".
I've seen a lot about replacing conventional combusters with PDEs over the past year or so.
Posted by Matthew G. Saroff | July 2, 2008 10:12 PM
Posted on July 2, 2008 22:12