From: skunk-works-digest-owner@mail.orst.edu To: skunk-works-digest@mail.orst.edu Subject: Skunk Works Digest V5 #326 Reply-To: skunk-works-digest@mail.orst.edu Errors-To: skunk-works-digest-owner@mail.orst.edu Precedence: bulk Skunk Works Digest Friday, 7 July 1995 Volume 05 : Number 326 In this issue: RE: X-35 Calculating the top speed of SR71 Re: D-21 and SR-71 Bruce Boland Dies and other comments Re: Calculating the top speed of SR71 Bruce Boland Dies and other comm Re: info request for the ufo warning More on Ramjet (SR71) speed limitations Re: More on Ramjet (SR71) speed limitations Me again... :) Re: Skunk Works Digest V5 #325 JP-7 fuel Re: Me again... :) See the end of the digest for information on subscribing to the skunk-works or skunk-works-digest mailing lists and on how to retrieve back issues. ---------------------------------------------------------------------- From: George Allegrezza 06-Jul-1995 0848 Date: Thu, 6 Jul 95 08:57:54 EDT Subject: RE: X-35 I first heard about an X-35 in a Rolling Stone(!) article of a few months ago. The article was about NASA's culture and discussed the uses of Digital workstations in the new JSC Mission Control Center. "X-35" was mentioned as an example of how NASA "young turks" were cutting red tape and getting things done, blah blah, blah. At the time I thought X-35 was a typo, and the author meant X-33. But, it appears X-35 is real, from some comments in sci.space.tech. Apparently it's a lifting body, (HL-10-like, as you said), and intended for resupply for/rescue from the space station. NASA's never been comfortable with the Soyuz as a lifeboat, and it's not surprising that a replacement design is in the works. Whether it'll ever get funded, of course, is another question. George George Allegrezza | Digital Equipment Corporation | "He has a perfect face for radio." Mobile Systems Business | Littleton MA USA | -- from "Quiz Show" allegrezza@ljsrv2.enet.dec.com | ------------------------------ From: Charles_E._Smith.wbst200@xerox.com Date: Thu, 6 Jul 1995 06:18:41 PDT Subject: Calculating the top speed of SR71 Folks, It`s really easy to calculare the top speed (in Mach number) of the SR-71. I`ll leave it as an exercise for some of the AE students here. If you`ve studied gas dynamics it will be a peice of cake. 1) Get a good side photo of a `71 2) Measure the angle of the diffuser cone, 3) Take std. atmosphere conditions for say, 70K feet. 4) Using the theta-beta-M diagram found in any compressible flow handbook, find the Mach number which relates to that angle. (Remember to use 1/2 of the cone angle!) 5) Enjoy! (serves six) Mach six is beyond ram jet range. At this velocity the flow in the combustion chamber would be supersonic. That DEFINITELY doesn`t happen on a SR71. Sorry to be the bearer of bad news. "Why stabbest thou thus at the poet`s heart, vulture, who`s wings are dull realities." -Edgar Allen Poe, "Sonnet to Science" Chuck Smith "Aerospace Engineer to the Stars" ------------------------------ From: Mary Shafer Date: Thu, 6 Jul 1995 10:40:54 -0400 (EDT) Subject: Re: D-21 and SR-71 The SR-71 can go up to about Mach 3.3 or 500 KEAS (fig. 5-3 in the Dash 1). It's an inlet temperature thing. Anything higher is nonsense. The Machmeter only goes to 4, too. Regards, Mary Mary Shafer DoD #0362 KotFR shafer@ursa-major.spdcc.com URL http://www.dfrc.nasa.gov/People/Shafer/mary.html Some days it don't come easy/And some days it don't come hard Some days it don't come at all/And these are the days that never end.... On Thu, 6 Jul 1995, Wei-Jen Su wrote: > Hello. I am majoring in Aerospace Eng. at Polytechnic University > and I wish to share some information to all of you and get some answer > (if you want and can). Since I am new in this mailing list (finally I > found that I was looking for), and I just want to tell the real maximun > range of the Lockheed D-21 drone (I don't know if you know this already). > "This figure was officially classified until very recently. It was > a shock to observers when, at a 1987 meeting, Skunk Works chief Ben Rich > disclosed that the D-21 had an endurance of no less than four hours at > Mach 3.8, translating into a total range of 10,000 miles -eual to that of > a B-52!!!!" (*) > Well, I wish to know the real maximum speed of the SR-71 > Blackbird. I asked to one of my friend that used to fixed the avionics > system of that amazing "Blackbird", he told me: "I don't know... but one > time that I went to fix that aircraft, I found out that the > speedometer was broke at Mach 6. something... I don't know if the > speedometer went crazy or that aircraft really reached that speed and the > speedometer broke at that point..." > Another proof that SR-71 can reach that speed is the following: > "In 1971, Senator Barry Goldwater became one of the first civilians > to take a ride in the SR-71. The SR_71 creator, Clarence L. "Kelly" > Jphnson, was there to brief Goldwater. After the flight-according to > SR-71 pilot Abe Kardong- Goldwater asked Johnson where the next step > would be. > Mach 6, Johnson replied." (*) > (*) This portion I got it from the book: "Aurora" by Bill > Sweetman. > Well, I have a good friend and he told me that he saw a manual of the > SR-71 very reliable whic I can't tell where is from (for security reason), > and it said that is Mach 10!!! I don't know if this is true. > Well, I will appreciate if someone answer me in public or > secrety. And as Mr. Spock used to say: "Live Long and Prosper". > > Su Wei-Jen > e-mail: wsu02@barney.poly.edu > ------------------------------ From: David Lednicer Date: Thu, 6 Jul 1995 08:21:53 -0700 (PDT) Subject: Bruce Boland Dies and other comments I just got a phone call (7/6/95, 0800) from a friend down at the Skunk Works. He tells me that word was getting around that Bruce Boland, one of the primary structural designers at the Skunk Works, now retired, died last night. I don't know the full list of projects he worked on, but he was one of the primary engineers on the F-117. As to why the XB-35/-49 was cancelled - I think I have finally found the REAL reason - the bomb bay wasn't big enough to take the atomic weapons of that period (they have gotten much smaller since then)! - ------------------------------------------------------------------- David Lednicer | "Applied Computational Fluid Dynamics" Analytical Methods, Inc. | email: dave@amiwest.com 2133 152nd Ave NE | tel: (206) 643-9090 Redmond, WA 98052 USA | fax: (206) 746-1299 ------------------------------ From: BaDge Date: Thu, 6 Jul 1995 10:18:57 -0400 (EDT) Subject: Re: Calculating the top speed of SR71 Chuck, Thanks for the post about calculating the speed. Most realize that inlet speed and temp are defining factors. I did hear that a special version of the SR was capable of higher speeds, but again, isn't 'sustained' speed really more important. I would suspect that you could put the plane in a dive and run fairly fast. Once. ;-) regards, BaDge ------------------------------ From: Jay.Waller@analog.com Date: Thu, 6 Jul 95 12:29 EDT Subject: Bruce Boland Dies and other comm I've always heard that politics played a factor in the cancellation of the XB-35/-49 as well as other factors. Is that true or just speculation? Jay ------------------------------ From: Alejo Hausner Date: Thu, 6 Jul 1995 13:58:27 -0400 Subject: Re: info request for the ufo warning Kean Stump writes: > > What other resoureces are available for those who wish to discuss ufo's, > the paranormal and all that? If I'm going to warn people off, it only > seems fair to tell them where they can go, if they choose 8) The FAQ for alt.alien.visitors is an excellent place to start. It's kinda fun to read it, whether you believe that nonsense or not. - -- Alejo Hausner (ah@cs.princeton.edu) ------------------------------ From: Charles_E._Smith.wbst200@xerox.com Date: Thu, 6 Jul 1995 11:21:55 PDT Subject: More on Ramjet (SR71) speed limitations Yes, temp plays a big role, but not so much the ambient as the total temperature. The total temp will be realized along any stagnation streamline. This is beyond the service temp of titanium at hypersonic velocities through the atmosphere. Also, the shock wave may be enough to thermally choke the flow, so no heat addition by combustion, nuke , or any other technology will make you go any faster! Actually, compressible flow is a lot easier than subsonic. Its all pretty much straight-forward algebra, which incidently, is why supersonic craft have boring straight lines and angles. Subsonic flow is a lot more esoteric, And is reflected in the complex curves found in "slow" aircraft. Compare a Harrier to a Tornado. Chuck ------------------------------ From: larry@ichips.intel.com Date: Thu, 6 Jul 1995 14:06:29 -0700 Subject: Re: More on Ramjet (SR71) speed limitations Chuck Smith writes: >Folks, >It`s really easy to calculare the top speed (in Mach number) of the SR-71. I`ll leave it >as an exercise for some of the AE students here. If you`ve studied gas dynamics it >will be a peice of cake. > >1) Get a good side photo of a `71 >2) Measure the angle of the diffuser cone, A photo of the inlet spike retracted full back, that is, as the inlet spike is full back at max cruise. >3) Take std. atmosphere conditions for say, 70K feet. >4) Using the theta-beta-M diagram found in any compressible flow handbook, find >the Mach number which relates to that angle. (Remember to use 1/2 of the cone angle!) To help them a little here, 'that angle' you mention, is the angle that the cone shock off the inlet spike makes when the cone shock off the inlet spike tip meets the inlet cowl lip. At max cruise, that is where the inlet spike shock will be because that is the minimum drag configuration for the spike shock. Measure both angles from the centerline of the spike, or the half-angles as you said. That will give them theta and beta and they can then read Mach No. off the chart. Also, usually the theta-beta-Mach no. charts in compressible flow books are for 2-D wedges and not 3-D cones. It will be close but as we know, cones have another degree of freedom and the angles of shocks through cones are slightly different than for wedge generated shocks. There are charts available for cones if you want to be very precise. >Mach six is beyond ram jet range. At this velocity the flow in the combustion >chamber would be supersonic. Should be supersonic, or would be supersonic? One could design a Mach 6 ramjet, although at that speed, the temperatures after shocking the flow down to low subsonic, would be close to the temperature limits and there would be little headroom to add heat via the fuel in the burner. Mach 6 is therefore near the transition point to scramjet. Perhaps that is what you meant. Scramjets like to run above the autoignition temperature for the fuel they are using unless they are piloted. There has been work with chemical pilots, in fact the first successful scramjet to develop thrust (in 1958) did so with a chemical pilot, or chemical ignition. > That DEFINITELY doesn`t happen on a SR71. >Sorry to be the bearer of bad news. Right. In the Barry Goldwater case that the original poster mentioned, Goldwater was asking about follow-on vehicles and that is what Kelly was talking about - follow-on vehicles, not the SR specifically. >Chuck, > >Thanks for the post about calculating the speed. Most realize that inlet >speed and temp are defining factors. > >I did hear that a special version of the SR was capable of higher speeds, I know of no 'special' SR that was capable of higher speed, beyond the normal variations. Back during the MD-21 program, there were special higher thrust J-58 engines that the SR fleet was slated to get. These engines were 'appropriated' by the MD-21 group for the M-21, due to the acceleration problem the M had going transonic in the MD-21 configuration. >but again, isn't 'sustained' speed really more important. Yes. High speed cruisers, have an on-design speed that they are usually designed for. > I would suspect >that you could put the plane in a dive and run fairly fast. Once. ;-) Actually, eventually, that is how the MD-21 configuration went supersonic. In a very steep dive after attaining altitude. Mary Shafer writes: >The SR-71 can go up to about Mach 3.3 or 500 KEAS (fig. 5-3 in the Dash >1). It's an inlet temperature thing. Anything higher is nonsense. Yes. In fact that is another way of calculating the maximum speed. I can't recall the specifics, but there is a simple rule-of-thumb involving CIT max I think. An SR driver told me this one. Larry ------------------------------ From: Wei-Jen Su Date: Thu, 6 Jul 1995 18:46:36 -0400 (EDT) Subject: Me again... :) Hello "Hot Shots"... I just want your opinion of how the German pilot with his Cessna 172 got in to the Red Square in Moscow. People told me that it is because the Cessna has a radar signiture very low and he was flying very very low. With his very low speed, the radar operator didn't take as treat or didn't see it. From my opinion, I think it was some Stealth technology that was install to the aircraft to test it and then is autodestroy once it reach his targert (Moscow). Su Wei-Jen wsu02@barney.poly.edu ------------------------------ From: Charles Date: Thu, 6 Jul 95 18:04:16 EDT Subject: Re: Skunk Works Digest V5 #325 From: jgladu@bcm.tmc.edu (John Gladu) writes: I'd been lead to believe that they went away because Jack Northrup refused to knuckle under to a government "request" that he merge his company with another (my brain is saying 'Mitchell'), and because of this refusal the 'wings were cancelled. According to "Winged Wonders", by E.T. Wooldridge, published by the National Air and Space Museum (1983), it was Convair. Although Northrop employees offered to finish the YB-49's in their spare time, Northrop had to turn it down, for fear of jeopardizing further military contracts. Stuart Symington was very specific that the YP-49 not exist any more; some say it was Symington's wish that Northrop lose as much money as possible, and thereby be forced to merge with Convair. Hope this helps, Charles ------------------------------ From: albert.dobyns@mwbbs.com (ALBERT DOBYNS) Date: Thu, 06 Jul 95 19:47:00 -0500 Subject: JP-7 fuel > Date: Wed, 5 Jul 95 13:55:01 +0200 > Message-Id: <9507051155.AA00627@glas1.awi-bremerhaven.de> > Subject: Re: SR-71, tail, smoke, h > From: jfiresto@AWI-Bremerhaven.DE (John Firestone) JF> In article uuout@mwbbs.com, albert.dobyns@mwbbs.com writes: > >This Explodes Brightly!! Bad joke, eh? Actually it stands for > >TriEthylBorane although some books use Tetra in place of Tri. It > >is used to ignite the JP-7 fuel used (or that used to be used) in > >the P&W J58 engines.... JF> Out of curiousity, what do they use to thicken the JP-7 to slow the > rate at which it oozes out of the wings? Actually I have never seen JP-7 fuel so I am not sure if it is thicker than other jet fuels. I have read in a few books that a sealer of some sort is injected into the seams of the planes fuel tanks (much of the fuselage and the inner sections of the wings). The sealer slows the leaks to an acceptable value but it can't seal them completely. Also I think the material breaks down after some number of hours of Mach 3 flight so the sealer has to be replaced. I wish I had more concrete numbers to post, but I never had the experience of working on any of those planes. Some of the NASA folks might tell us some numbers or perhaps some of the other major Blackbird fans know the answers. Al -- always looking for the last piece of info on the SR-71. - --- þ SLMR 2.1a þ Nostalgia: the good old days multiplied by a bad memory. ------------------------------ From: megazone@world.std.com (MegaZone) Date: Thu, 6 Jul 1995 23:08:19 -0400 (EDT) Subject: Re: Me again... :) Once upon a time Wei-Jen Su shaped the electrons to say... > From my opinion, I think it was some Stealth technology that was >install to the aircraft to test it and then is autodestroy once it reach >his targert (Moscow). Sorry. 1. You can't passively reduce RCS electronically (unless there is some WAY serious tech out there). You could coat the plane, but not and destroy the entire coating. 2. You can actively jam radar and spoof it - but you *know* when you are being jammed and spoofing creates other targets. 3. The Russians *did* track the aircraft, it was detected. The problem was it was a holiday and most of the air defense people were trashed (drunk). So nothing was done - that is why so many people got in trouble. If the aircraft had snuck in, that is one thing. The system is deficient. But it was seen and not stopped - the people were deliquent in their duty. - -- megazone@world.std.com (508) 752-2164 MegaZone's Waste Of Time Moderator: anime fanfic archive, ftp.std.com /archives/anime-fan-works; rec.arts.anime.stories - Maintainer: Ani Difranco Mailing List - Mail to majordomo@world.std.com with 'subscribe ani-difranco' in the body. ------------------------------ End of Skunk Works Digest V5 #326 ********************************* To subscribe to skunk-works-digest, send the command: subscribe skunk-works-digest in the body of a message to "majordomo@mail.orst.edu". 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