Forum: Modern Military Aircraft

count_to_10 wrote:

That's a ram jet.
The CDE I have seen just used compressed air, with the detonation waves traveling around in a circle, not hanging on a surface in a supersonic flow.
http://www.youtube.com/watch?v=QbJgOk2rDbI

So how you going get THAT much compress to run a fighter sized engine?

Given your CDE is using compressed air indicates it's a RAM jet engine yes, but without hyper-sonic speeds, how to you compress air into an open ended engine without letting the shock wave from the detonation from moving back up the inlet?

The model test in the video appears to weigh a lot and is fed compressed air (or gasses) from an external source. More applicable to a rocket design.

When you get CDE to work in an F100 sized motor from zero airspeed/altitude using normal hydro-carbon based fuels give me a call. I don't see this happening in the next few decades in time for any F/A---- ? program.

But good luck! Cheers

TEG

F-16.net Sponsor

I'm not at all involved with the CDE, TEG, I just found information on it looking around for something else. Like I said, my understanding is that it would only replace the combustion chamber, being fed air from a compressor pushed by a turbine. As for for how long it would take to incorporate the concept in to a production engine (or even if it can be made to work), I have no idea. A lot can happen in 20 years, though.

count_to_10 wrote:

it would only replace the combustion chamber, being fed air from a compressor pushed by a turbine.

The temperatures you're talking would be extremely difficult to deal with in a turbine. Likewise getting a compressor to reach that sort of compression/flow would be difficult (to say the least) to obtain. One would also have to consider the shock waves being pushed around inside the combustion chamber and their effects on the exit flow of the compressor. I'm thinking it would be a stall-margin nightmare for a compressor design.

The best application IMO would be in a ram-jet configuration at hyper-sonic speeds.

Cheers

TEG

Actually, the exit temperatures tend to be pretty low (because the compression ratio in the detonation is high), but I do remember that there was a lot of concern about slowing and homogenizing the flow coming out the back.

If pictures are worth a thousand words, what do these pictures say?

http://defense-update.com/20130408_boei ... ghter.html

Looks like a dedicated manned and unmanned version.

Canards?
Is that not as hard on RCS as has been bandied about?
Emphasis on super-cruise?

Canards could definitely allow for flexibility in overall wing layout and planform design, with RCS, performance and low approach speed handling all coming into the calculus. Canards alone shouldn't destroy RCS either, as long as they are designed as part of an overall 'LO' requirement for the concept. Besides, if one is replacing the canted tail with canards, there might even be a net improvement in terms of RCS, no?

As a potential poor mans F/A-XX option, i'd personally like to see an evaluation for an 'F-16XL-type' concept, but conceived for the existing Super Hornet model. Perhaps design an F-23 type wing and all-moving tail to be integrated onto the Super's airframe, and add canard? Integrate the CFT, enhanced F414 engine and the centerline weapons pod and call it a day for about what, 50% the Development and procurement cost!?! Heck, USAF might even want to kick the tires of that thing Wink

Forum: Modern Military Aircraft

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