Liquid Rhino

That picture is incredible... but the caption?!? SR-71 on taxi with engines... as opposed to what, without engines? Excuse my military ignorance, but are the engines removable for storage or something, or is it just a figure of speech?

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Richard Paul

With engines on full afterburner.
RG I have a picture like that but can't find it right now. This one leaves something to be desired

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Hymee

Nice piccy. They are a very sleek machine. I've seen one up close at the US Space and Rocket Center, Hunstville AL.

The whole plane looks like a life support system for 2 big honk'n engines and a camera!

Cheers,
Hymee.

rotarygod

It is! Oh yeah there are pilots in there too.

Richard Paul

All it has to be is a fuel tank and control surfaces. And the engines themselves only produce about 25% of the power themselves. the rest is done from the pressure of the intake. Utilizing that spike you see in the inlet. It moves in and out to adjust the pressure into the combustion chamber.

Meaning they use the intake to pressurize and heat the air. We don't know how but they must completly bypass the compressor and just inject fuel into the incoming air and burn it. then inject more fuel into the burning exhaust for afterburner. They fly on afterburner all the time. Unlike say a fighter plane.

Read Ben Rich's book "Skunk Works". You'll have the best time with some of the pilot statments flying the SR 71. I read it in one sitting, couldn't stop. By the way Ben Rich was responsable for the F 117. Kelly Johnson was responsable for something like 36 plane designs by himself. Including the P-38 and U-2. The last being the SR-71. Probably could never have been built if not for that one man. No one else would have the nerve or the authority to propose such a thing to the CIA for funding.

Oh yh, speaking of pilots there RG. Ben Rich designed the air conditioning system. The cocpit skin temp gets to about 800 F. He said if it failed to pilot would be well done in 15 min. med in 10.

Richard Paul

Here's another thing they had to think about. If the intake to exhaust is say 20 feet and you are traveling at mach 3.5 how long does the slug of air going in have to enter get mixed with fuel combusted and spit out the back. Can that prosses happen in that amount of time. We know now that it can but think how they thought.

Speed of sound at -60 f is 2root of 400 x 49= speed in f/s or 980 f/s x 3.5=3430 f/s
so 1 over 3430=.00029 sec for each foot or .0058 sec from entry to exhaust

Can all that chemistry happen in .0058 of a second??
No one had ever flown a jet that fast. All high mach numbers were done with rocket power.

bureau13

Let's give credit where credit is due. We all know the true technological foundation for this thing came from a downed "weather balloon" in Roswell, NM circa 1947. :D

jds

Richard Paul

Didn't they decide that it was some labrotory test dummys that landed there?
They were testing high altitude bail outs.

rotarygod

There were definitely dummies there!

Gomez

Here are my favorite SR-71 stories.... :D

I remember reading something about these aircraft years back......something about them leaking like sieves when refuelled as the tanks didn't fully seal until they were up to temp at high Mach...?

Regards, Gomez.

Turbine_pwr

Thought I would chime in with some additional info on the engine for the SR-71. It's known as the J58 and was/is manufactured by Pratt&Whitney engines. If you look closely at the attached picture.... you will see a set of tubes that come off of the compressor and dump back behind the turbine. In essence this was the first mixed flow turbofan engine. However, only approximately 40% of the core flow was ducted around the rotating machinery. The US Air Force Museum at Wright Patterson AFB in Ohio has the most complete display of this vehicle and it's earlier development models. This is a great museum to visit if you're ever in the area. I think one of the best aircraft musuems in the world... and the price is FREE.

I scarffed this off their web sight at;US Air Force Museum

Pratt and Whitney J58 Turbojet Engine
The J58 engine was developed in the late 1950s by Pratt and Whitney Aircraft Division of United Aircraft Corporation to meet a U.S. Navy requirement. It was designed to operate for extended speeds of Mach 3.0+ and at altitudes of more than 80,000 ft. The J58 was the first engine designed to operate for extended periods using its afterburner, and it was the first engine to be flight-qualified at Mach 3 for the Air Force.

Two J58s power the highly-sophisticated Lockheed SR-71 high-altitude strategic reconnaissance aircraft as well as its forerunner, the Lockheed YF-12A prototype interceptor. In July 1976, J58 engines powered an SR-71 to a world altitude record of 85,069 ft. and another SR-71 to a world speed record of 2,193 mph.

Because of the high-temperature environment in which the engine operates, it uses low-volatility JP-7 fuel which requires a chemical ignition system. The engine on display is a prototype version of the J58 and was used as a ground trainer before being transferred to the Museum.

SPECIFICATIONS
Model: J58
Compressor: 9-stage, axial flow, single spool
Turbine: two-stage axial flow
Thrust: 32,500 lbs. with afterburner
Weight: approx. 6,000 lbs.
Max. operating altitude: above 80,000 ft.

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Turbine_pwr

Some more cool information and a better picture...

Pratt & Whitney J58 Turbojet
The Pratt & Whitney J58 engine was a nine-stage, axial-flow, bypass turbojet originally developed in the late 1950s to meet U.S. Navy requirements. It was the first jet engine designed to operate for extended periods using its afterburner. The J58 generated a maximum thrust of 32,500 pounds -- more than 160,000 shaft horsepower -- and was the most powerful air-breathing aircraft engine yet devised. The J58 was specifically tailored for operation at extreme speeds, altitudes, and temperatures, and was the first aircraft engine to be flight qualified for the Air Force at Mach 3. At maximum output the fuel flow rate in the J58 is about 8,000 gallons per hour and the exhaust-gas temperature is around 3,400 degrees. The J58 was only used on the Lockheed YF-12 interceptor and its descendents, the A-12 and SR-71.

The J58 required the use of a special AG330 engine starter cart to spool the engines up to the proper rotational speed for starting. The cart was powered by two unmuffled Buick Wildcat V-8 racing car engines which delivered a combined 600 horsepower through a common gear box to the starter drive shaft of the aircraft engines. The J58s had to be spun up to about 3,200 RPM for starting.

The variable-geometry inlets for the engines were quite complex and intricate. The most prominent feature was a hydraulically-actuated conical spike which was automatically moved forward or aft by the Air Inlet Computer as required to keep the supersonic shockwave properly positioned in relation to the inlet throat. Working in conjunction with a series of bypass ducts and doors, the spike prevented supersonic air from entering the inlet and maintained a steady flow of subsonic air for the engine. At Mach 3.2 cruise the inlet system itself actually provided 80 percent of the thrust and the engine only 20 percent, making the J58 in reality a turbo-ramjet engine.

At the speeds the SR-71 operated, surface temperatures were extremely high due to aerodynamic heating: 800 degrees at the nose, 1,200 degrees on the engine cowlings, 620 degrees on the cockpit windshield. Because of the operating altitudes, speeds, and temperatures, Lockheed designers were forced to work at the cutting edge of existing aerospace technology, and well beyond in many cases. Many features and systems simply had to be invented as they were needed, since conventional technology was inadequate to the task. New oils, hydraulic fluids, sealants, and insulations were created to cope with the ultra-high temperatures the craft would encounter. A new type of aviation fuel, JP-7, was invented that would not "cook off" at high operating temperatures, having such a low volatility and high flash point that it required the use of triethylborane as a chemical ignitor in order for combustion to take place. The fuel itself was rendered inert by the infusion of nitrogen and then circulated around various components within the airframe as a coolant before being routed into the J58 engines for burning.

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rx8 dx

Too bad we can put one of those monsters in our cars,

bowman

A turbojet will not solve the low torque problem. Go with a gas turbine. A T55-L-714A puts out 4733 shaft hp.

With that hp, you might need some transmission work, though. :D

Hymee

Cool info turbine_pwr. That was a great read!! Love the 2 stand-alone V8s just to spool up the engines!

Gomez,

I also liked another flying/ATC quote I saw... It was about a B52 coming in for an emergeny landing with one engine shut-down. A fighter pilot requested a priority landing clearance due to some malfunction, but was refused due to the B52's problems. The fighter pilot replied "Oh no - the dreaded 7-engine approach!!" ROFLMAO!!

Cheers,
Hymee.

ranger4277

If any of you are in Dayton to check out the AF Museum, let me know. I live right down the street.

Now back to boost.

funk_da_fyd

Show me all the facts, and I'll buy two.

RX8-TX

The Blackbird has been one of my ALL TIME favorite airplanes -since I was probably 9y/o.

Richard Paul

Nice to hear from turbine again. Thought the SR might get you talking.
No one has mentioned that this was the first real use of Titanium. When they desided to use it there was only one company selling it and it was of varying quality. Lockheed had to do the development work in secret. They even had to buy it from the Soviets. They had to set up phony copanys all over the world to hide the fact that they were the end users.

They couldn't drill the stuff or work it. they wound up doing all research on the stuff. They wound up building 13 million separate parts.

Other matirials were, Hastelloy x for ejector flaps, Elgiloy for control cables. plumbing was gold plated.

The piolot story I like best is when we needed to fly over Lebinon after the marine barracks bombing. France wouldn't let us fly over their air space(naturaly).
So going the roundabout way required two air refuelings. When the left for home one engine gave a low oil pressure warning. The pilot pulled back on the throtles and droped down.
They decided to go over France anyway to get back to England faster. All went well for awhile until he saw a French Marage lll off his wing. the guy comes on the radio asking for their diplomatic pass number. Pilot told him to stand by because he had no idea what he was talking about. He asked his backseater who replied don't worry I already gave it to him. What he gave him was the finger. The pilot nailed the afterburners and left the frog standing there. Two minutes later they were over the channel.

Hymee

Rihcadr Pual si very tired :p

RXhusker

This is one of my favorite places in Omaha -- gets your blood pumping every time as you walk into the SAC museum underneath an SR-71 :D

Richard Paul

Your right Himie, dna i'm gonna leev it that whay.

RxHusker, yes it is. Nice pic. Once they did a low flyby at Reno. Then nailed it at the end of the runway. Nobody knew it was coming except they hand wrote it in on the race timing posted in the pits only. So it was a slight supprise to us and a complete one to the crowd. Once I heard those engines it made wonder what I was doing working on a Merlin which seconds ago I though was the greatest thing ever built.

Then an F-15 came down the runway standing on it's tail then goes 90 degrees up into the air over our head. Looking up into those afterburners I said to Zeuschel (whom I was working with on a P-51) what the hell are we working on this thing for? To which he said "because the govm't wouln't let you have one and that 26 year old kid just burned up 4000 lbs of fuel."

olddragger

All these stories are great! Surprising technology? No. What would you say if I told you that I saw plasma TV's 12 yrs ago? There is a lot of stuff I can't talk about.
Keep going Richard I hope your work is proceeding well an there is not any muda.
olddragger

Ajax

I fly an SR-71 to work everyday.

ok.. no... i don't.. that's a lie..

Liquid Rhino

Richard, sorry to digress this thread's current topic of discussion (the SR-71), but I'll be quick... (I Promise! You guys can talk about the Blackbird all you want after this post!)

I understand that you are currently working on another priority project as well as the two prototypes for the 8 that you mentioned earlier.

Basically, I just wanted to remind you while you are still in the development phase of the compressor not to forget about the many automatic underdogs here like many aftermarket companies do when it comes to Induction and/or ECU Tuning. Believe me when I say we probably need these upgrades more than our stick friends, being that we have the lower end of the HP straw.

I'm sure that many auto owners both understand some of the restrictions/issues (tranny holdup, extra ports, etc.) that may amount to not possibly having as much of a boost/hp as manual users, as well as simply want just that little bit more 'push' on their rides.

The truth is, no matter how much some will argue about the true sport this and thats, most sportscar auto owners do this for necessity, such as multiple drivers, price (in the case of the 8), maintenence of the clutch etc., rather than driving preference or knowledge of the tranny. But we should also be able to take advantage of what CAN be available for our cars just the same, and many of us are more than willing to invest in such options.

The last thing I want to accomplish here is to start a posting flood or flame war, although any CONSTRUCTIVE comments on what can/can't work here would be more than appreciated by yourself or the club members.

All I really ask is that, even if it takes a bit longer to perfect, please don't leave us out of the loop, we're more than interested too ! :o

Thanks again for your time, Richard.