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Lockheed ADP/NASA Langley 1990 Mach 4 - Mach 5 methane fueled aircraft studies

flateric

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AlAA 90-2151
Airframe/Propulsion Integration of Supersonic Cruise Vehicles
J. Anderson
Lockheed Advanced Development Projects
Burbank, CA

"...A system performance study was conducted by the Lockheed Advanced Development Projects (ADP) organization under a subcontract to Pratt & Whitney in support of the Air Force Enhanced Flow Compressor contract. This study investigated the system performance, impacts of the inlet/lengine match and the implications of engine flow scheduling vs Mach number.
The baseline aircraft used in the study was a derivative of the Mach 5 methane fueled cruise vehicle developed in a joint effort between ADP and NASA Langley - (pics 3 and 4 - Flateric). The derivative aircraft was a Mach 4, JP fueled aircraft. Both aircraft were designed for long range cruise at their respective design Mach numbers. The baseline aircraft was configured with propulsion
nacelles located on the wings. For this study, these nacelles were removed from the aircraft design and replaced with the various new inletlengine combinations being studied."
 

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hesham

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Hi,

here is the Lockheed hypersonic,they called
it Mach 7.

http://books.google.com.eg/books?id=y-QDAAAAMBAJ&pg=PA71&dq=Mach+5+aircraft&hl=ar&ei=dTxATPHYFMuK4QaB8q2nDg&sa=X&oi=book_result&ct=result&resnum=16&ved=0CHMQ6AEwDw#v=onepage&q=Mach%205%20aircraft&f=true
 

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dannydale

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I think it was just listing the speed of the different vehicles, and this one got the 'Mach 7' label. Some of them also look a bit fanciful, like the Akula (I think) submarine's long tail and the weird hydroplane boat. Others like Thrust 2 look nearly dead-on. I was also wondering about the glowing leading edges on Mr. Lockheed Mach 7 in light of the mountains in the background implying he's flying in the dense lower atmosphere. I think an object going M7 at STP would give off intense blue-white or even violet-white light just like an arc welder.

Bravissimo for finding a view of Mr Lockheed's belly. That ranks up there with the various FDL and waverider hypersonics as my favorite unbuilt designs.
 

Colonial-Marine

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Excuse my ignorance, but why methane? I know it has been looked at for powering more conventional aircraft as well as rockets, but what makes it applicable to a Mach 4+ design?
 

Orionblamblam

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Colonial-Marine said:
Excuse my ignorance, but why methane? I know it has been looked at for powering more conventional aircraft as well as rockets, but what makes it applicable to a Mach 4+ design?
1) It's cold. Useful for cooling an aircraft at those speeds.
2) It combusts faster than regualr jet fuel (important when dealing with speeds that put air through engines in *milliseconds*
3) It has more energy per unit mass than regular jet fuel.
4) It's denser than hydrogen.
5) It can be manufactured easily, unlike jet fuel.
6) There's lots of it underground.

Main negative of methane is that it's substantially less dense than regualr jet fuel, and is more difficult to handle.
 

DSE

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Orionblamblam said:
Main negative of methane is that it's substantially less dense than regualr jet fuel, and is more difficult to handle.

Another not so nice property is it's tendency to detonate more easily than say H2.
 

shockonlip

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dannydale said:
Hay guise! I found something that looks suspiciously like an engine nacelle from this beast!
...
Yes, there are a fair number of papers on this study whose titles are unclassified, but the body
of the paper is still secret.

There are also a few papers that are actually published and available via AIAA.

If you want to get excited and then frustrated:
http://www.secretprojects.co.uk/forum/index.php/topic,10338.msg97434.html#msg97434

Regards.
 

shockonlip

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By the way.

The ISABE paper that can be found via the previous link is available via the
ISABE proceedings.

I have a copy. Interesting paper!

The 2-D inlet did not perform as well. A vortex instability on the sidewall from what I
recall. But the axisymmetric inlet did better (see flateric's 2 pix at the start of this
thread).

Also, the design called for the ramjet to cold-flow until it was needed.
I found this very interesting.
 

Mr London 24/7

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dannydale said:
Hay guise! I found something that looks suspiciously like an engine nacelle from this beast!

http://crgis.ndc.nasa.gov/historic/File:1982_Mach_5_Nacelle_Multiple_Expansion_Ramp_Nozzles.jpg
I previously missed this: nice find - I'm sure there is a .pdf on DTIC or NTRS covering Wind Tunnel testing of (what seemed very likely to have been) this Inlet (but it may not have been specifically identified as such)....
 
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