Russian Aerospace Firm Develops Mach 7.5 SCRAMJET engine

a reply to: darksidius

i was told that it's not actually the altitude but the friction of the air that causes the heat.

that got me thinking. why don't they invent a lubricant for the wings? make like opening along the leading edge and pump lubricant onto them while travelling at high speeds? wouldn't that work? it could even have a fancy aerospace name. I'm thinking Astroglide. I'm gunna call the copyright office and see if I can copyright the name. it's catchy.

a reply to: darksidius

Really? You know its top speed and are able to say that with such absolute certainty?

originally posted by: Zaphod58
Interestingly U-2 pilots have been found to have 4 times the volume, and 3 times the frequency of brain lesions as non-pilots. The only factor that is common is the high altitude flights they perform. Since 2006, when flight duration and frequency increased, the number of lesions and pilots with them has increased significantly.

www.medscape.com...

That is interesting since they wore space suits where fighter pilots do not, and only wear pressure suits. The biggest problem is getting the O2 into the blood and so they use a system that forces the O2 into the lungs under pressure at high altitudes that basically pressurizes the lungs to a lower altitude allowing the O2 to enter the blood, but I'm not sure what the limits are, or if they pressurize the cockpit, one would think they do.

BTW forced O2 is extremely tiring...

a reply to: Xtrozero

They pressurize the cockpit, but until about 2012, they pressurized it to 29,000 feet. Starting in 2012, they retrofitted them, and lowered the pressure altitude to 15,000 feet.

You know what else is extremely tiring? Having to move the controls in a U-2. They aren't hydraulically assisted, and require as much as 75 lbs of force to move them IIRC.

originally posted by: Zaphod58
a reply to: Xtrozero

They pressurize the cockpit, but until about 2012, they pressurized it to 29,000 feet. Starting in 2012, they retrofitted them, and lowered the pressure altitude to 15,000 feet.

You know what else is extremely tiring? Having to move the controls in a U-2. They aren't hydraulically assisted, and require as much as 75 lbs of force to move them IIRC.

Big big difference between 29,000 and 15,000. Above 18,000 the deluter/demand O2 system kicks in. I flew in the AF with a prior U2 pilot. I asked him why he left that program and he said that it is the most unforgiving airplane ever made and a pilot much better than him died in one....

a reply to: Xtrozero

There's about 15 knots between stalling, and breaking up due to overspeed, they frequently suffer from the bends and other pressure related issues, 12 hour missions in a non-hydraulically assisted aircraft, and there's a good chance you'll stall and crash on take off.

Yeah, it's a real bitch.

a reply to: BASSPLYR

The Yanks have just done a deal with Reaction Engines Ltd of the UK to share the tech behind the Sabre Engine..

I imagine, given the funding differences between Russia and the West, that we (the west) will have one flying long before the Russians do.

If there are failures at a certain point but with different designs seems to be pointing to a natural cause with airflow.Harmonics and material strength could be a cause or at the 8 minute mark they could be hitting a wall aerodynamically like what happened with the sound barrier back in the 40,s..

originally posted by: Zaphod58
a reply to: Xtrozero

There's about 15 knots between stalling, and breaking up due to overspeed, they frequently suffer from the bends and other pressure related issues, 12 hour missions in a non-hydraulically assisted aircraft, and there's a good chance you'll stall and crash on take off.

Yeah, it's a real bitch.

I was told it is about 3 knots on landing between stalling or doing another go-around in the pattern.

a reply to: Xtrozero

Fifteen knots is with a clean airframe at altitude.

a reply to: Zaphod58

Which, in that light, makes the relatively docile handling of the SR-71 that much more impressive, given it's similar flight envelope.

Although I'm curious about whether the RB-57's and WB-57's were as much of a b*tch to fly as the U-2...

originally posted by: Zaphod58
a reply to: Xtrozero

Fifteen knots is with a clean airframe at altitude.

I understand, my point is just like yours in the margins are so tight that for a simple landing there is just a few knots difference between flying all day or stalling...

a reply to: Zaphod58
No I don't know , may be possible more on mach 4 than mach 7 if you want something survive the heat. I make a little provocation on it

a reply to: darksidius

At which point, why bother with endless headache of a scramjet when much more proven tech like ramjets and turbo-ramjets can more than do the trick for those mach ~4 speeds.

At least, if my assumptions based on altitudes mentioned, observed apparent speeds, and suppositions about why all the SR-71's/A-12's ended up in museums with nary a J58 to be found are correct, the Green Lady already more or less does that using a supposedly much more conventional powerplant with only a couple hop-ups.

a reply to: Barnalby

There is very little conventional about the tricks used in that engine.

a reply to: Zaphod58

Using the car analogy, I figured that if the F-15 was a smallblock-powered 'Vette and the blackbird was a turbocharged W-16 Bugatti Veyron, then scramjets were more like the Chrysler Turbine or the hydrogen fuel cell cars.

Pushing that analogy far past its breaking point while not knowing the specifics, I figured the Green Lady to be more like an alcohol-injected high-pressure turbo with direct injection and electric spool assist, with an electric hybrid kinetic energy recovery system and electric AWD system.

Meaning: a "conventional" powerplant with the most exotic add-ons that you can imagine to recover every last bit of possible performance. It might be TEB, it might be MHD, it might be precooling, and it probably is all of the above and then some. But at it's core, I'm guessing there's probably something that we'd recognize as a jet engine.

a reply to: Barnalby

Putting it that way, I'd agree.

a reply to: Barnalby
So mach 3/4 is the more real world

a reply to: darksidius

Though I'll openly muse about whether the Green Lady was designed as some sort of "low"-tech hedge against against the scramjet-powered Blackswift/SR-72 designs, as the USAF has done in the past (B-52 vs the B-58/70, anyone?).

a reply to: Barnalby

MHD research has been happening down here in Wiltshire for a long time, although when applying the technology to propulsion the Russians beat all of us to it, they were dabbling with that technology back in the 80's. MHD development has gone fairly quiet, it could be because the technology is useful/being used, or it could be because it's just not that good. As for TEB, I'm sure you know TEB is good for igniting things, including things you don't want it to.

Sabre is making lots of very important people in the industry get very excited.

The Russians are working with the Chinese and investing heavily in hypersonic research, Zaph you're right it's hard but the Russian/Chinese alliance is making serious headway. I think Bassplyr is right to be a little bit concerned.

Cheers
Robbie