JP-7 - Detailed Research - Part II


Message posted by Kurt on August 13, 2009 at 10:59:48 PST:

Peter Merlin makes a good point in his post (http://www.dreamlandresort.com/forum/messages/29602.html) about testing. I appreciate that. It inspired me to do more research. There have been over 4000 tests of scramjet engines through 2008 at NASA's LaRC Langley, VA facility (http://hapb-www.larc.nasa.gov/Public/Engines/engine_tests.html) and a TBD number of tests at the USAF AECD Arnold AFB, TN (http://www.arnold.af.mil/news/story.asp?id=123160209).

The X-43C was supposed to use a hydrocarbon fuel, perhaps JP-7, but was cancelled before being built. The X-51 uses JP-7 as does Falcon Combined-cycle Engine Technology (FaCET) scramjet. As far as I can determine, ALL other US scramjets used liquid hydrogen for fuel.

Hypersonic wind tunnels are required for scramjet testing. They cannot even run in supersonic wind tunnels. The only other US facility that I can find besides LaRC and AEDC that has hypersonic testing capability is Plum Brook Station (PBS) in Sandusky, OH which is operated by NASA Glenn Research Center (http://www.nasa.gov/centers/glenn/home/index.html). It appears their work is rocket-related and I can find no reference to scramjet testing conducted there. Finally, when hypersonic testing is conducted, the duration of the test is extremely short, in the order of milliseconds. Given the limited number of JP-7 powered scramjet tests, the small size of the engines, and the short run times, I seriously doubt that many thousands of gallons of JP-7 fuel has been, or will be, consumed by those efforts.

I finally tracked down the RFI that I mentioned in my previous posting. It makes for interesting reading. You can read it yourself at (https://www.fbo.gov/index?s=opportunity&mode=form&id=785935551d169339a5f31cbbd16ef89e&tab=core&_cview=1&cck=1&au=&ck=). To quote "The Department of Defense (DOD))is investigating the feasibility of JP-7 fuel requirements of up to 110,000 gallons, or any portion thereof, for delivery starting in the FY10 – FY12 timeframe. Distribution of the 110,000 gallon quantity would be 100,000 gallons to Edwards AFB, CA and the remaining 10,000 gallons to Wright-Patterson AFB, OH. The storage stability requirements outlined in paragraph 4.5.3 of MIL-DTL-38210 will be waived. The PWA-536 lubricity additive required by the specification will be provided by the Government."

So now we have a SUBSTANTIATED requirement for 110,000 gallons. They want it in 2010-2012. There is no possible way that Edwards AFB is using it for ground tests of the X-51 because they don't have a hypersonic wind tunnel. There is no possible way it is going to get consumed by the four planned X-51 flight tests. This is a tiny aircraft (http://www.parabolicarc.com/2009/08/05/x51a-waverider-prepared-december-test-flights/) and (http://www.popularmechanics.com/technology/military_law/4203874.html?page=3). I doubt it holds 20 gallons maximum. Besides, all four planned X-51 tests should be completed by April 2010. And why would a scramjet need the lubricity additive? I believe it was necessary for the J-58 because the fuel was also used as the engine hydraulic fluid. The engine hydraulic system is typically used for actuators such as those working the variable exhaust nozzle.

Something, in addition to the X-51, is using JP-7 and whatever that something is, it's going to need 100,000 gallons of JP-7 over a two year period beginning in 2010. That's really quite a bit of fuel. If it's a scramjet program, it's either a big aircraft, or there are a LOT of flights planned. My guess is this is for some type of prototype or limited initial operating capability testing. The fuel is being used in a similar manner as in the SR-71, thus the PWA-536 additive. That suggests a complex engine, perhaps a turboscramjet or some other combined-cycle type. Finally, additional requirements beyond the 110,000 gallons are possible. The RFI includes the following wording: "State incentives and/or obligations (e.g., R&D, capital investment, investment or production incentives) needed to develop and sustain long-term domestic commitments to produce JP-7 turbine fuel". That further suggests something operational.


In Reply to: Re: JP-7 - Detailed Research posted by RG on August 12, 2009 at 12:45:40 PST:

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