SR-72

a reply to: nelloh62

You would still have an upper limit, because you'd eventually reach where the turbines just couldn't keep up anymore.

Hypothetically of course.

a reply to: Soylent Green Is People
If you know your chemistry, you can figure it out. And since when do you need running engines to land?

originally posted by: Zaphod58
a reply to: Soylent Green Is People

Hypothetically, imagine what could be done if they were able to remove that turbofan speed limit.

Would some sort of pre-compressor cooling be the way to go or are we talking of a more 'exotic' solution... hypothetically ofcourse...

edit: would it really be a turbofan engine with a bypass? I would think you would go pure turbojet at such high speeds

a reply to: spaceman42

Hypothetically you would use more exotic tech.

originally posted by: Zaphod58
a reply to: spaceman42

Hypothetically you would use more exotic tech.

Hypothetically, a lot of chemistry and hot chemical reactions are involved..hypothetically.

originally posted by: Krakatoa
a reply to: Soylent Green Is People
If you know your chemistry, you can figure it out. And since when do you need running engines to land?

You don't, but I'm talking about a way to get the plane from zero velocity sitting on the runway up to speeds high enough in flight for the ramjet/scramjet to be able to kick in.

The ramjet/scramjet only works when they aircraft is moving at somewhere around Mach 3 to Mach 3.5. Therefore, before that ramjet and scramjet engine that can make the SR-72 move really fast (say Mach 6 or 7, or even faster) can work, the plane needs to be able to get up to speeds exceeding Mach 3. At the moment, it seems the issue is that there are no turbofan jet engines capable of getting the SR-72 moving that fast for the ramjet to kick in (the limit for turbojet engines is somewhere below mach 3 at the moment).

There are other ways the get a plane up to the speeds required for the ramjet to kick in (such as drop it from a separate carrier plane and use rocket thrusters), but it seems what they are looking for from the SR-72 is a single plane that can take off like a normal plane under jet power, then be able to get up to the speeds required for the ramjet to kick in, and then eventually the scramjet.

a reply to: Soylent Green Is People

Combined cycle ramjet. It slices, it dices, it makes julienne fries.

a reply to: spaceman42

wonder if compressed air would work as a pre compressor cooler? Like hypothetically speaking use plasma blooms at specific places right in front of the inlet to act as a virtual inlet cowl compressing the air and cooling it before it goes into the intake? Combine it with New materials inside the turbine that are light and extremely heat resistant. Throw in some chemistry out the back. = really fast engine?

originally posted by: Soylent Green Is People

originally posted by: Krakatoa
a reply to: Soylent Green Is People
If you know your chemistry, you can figure it out. And since when do you need running engines to land?

You don't, but I'm talking about a way to get the plane from zero velocity sitting on the runway up to speeds high enough in flight for the ramjet/scramjet to be able to kick in.

The ramjet/scramjet only works when they aircraft is moving at somewhere around Mach 3 to Mach 3.5. Therefore, before that ramjet and scramjet engine that can make the SR-72 move really fast (say Mach 6 or 7, or even faster) can work, the plane needs to be able to get up to speeds exceeding Mach 3. At the moment, it seems the issue is that there are no turbofan jet engines capable of getting the SR-72 moving that fast for the ramjet to kick in.

There are other ways the get a plane up to the speeds required for the ramjet to kick in (such as drop it from a separate carrier plane and use rocket thrusters), but it seems what they are looking for from the SR-72 is a single plane that can take off like a normal plane under jet power, then be able to get up to the speeds required for the ramjet to kick in, and then eventually the scramjet.

Again, chemistry is your friend...it can span many gaps, especially when it results in a highly reactive display of energy.

a reply to: Krakatoa

I'm wondering how "green" for the environment this chemistry would be. I mean it sounds pretty toxic and dangerous.

originally posted by: BASSPLYR
a reply to: Krakatoa

I'm wondering how "green" for the environment this chemistry would be. I mean it sounds pretty toxic and dangerous.

Yes, very toxic and dangerous. You would probably need a presidential determination that indemnifies its production and use for national security reasons too.....hypothetically of course.

a reply to: Soylent Green Is People

Its all here
www.reactionengines.co.uk...

originally posted by: Krakatoa

originally posted by: Soylent Green Is People

originally posted by: Krakatoa
a reply to: Soylent Green Is People
If you know your chemistry, you can figure it out. And since when do you need running engines to land?

You don't, but I'm talking about a way to get the plane from zero velocity sitting on the runway up to speeds high enough in flight for the ramjet/scramjet to be able to kick in.

The ramjet/scramjet only works when they aircraft is moving at somewhere around Mach 3 to Mach 3.5. Therefore, before that ramjet and scramjet engine that can make the SR-72 move really fast (say Mach 6 or 7, or even faster) can work, the plane needs to be able to get up to speeds exceeding Mach 3. At the moment, it seems the issue is that there are no turbofan jet engines capable of getting the SR-72 moving that fast for the ramjet to kick in.

There are other ways the get a plane up to the speeds required for the ramjet to kick in (such as drop it from a separate carrier plane and use rocket thrusters), but it seems what they are looking for from the SR-72 is a single plane that can take off like a normal plane under jet power, then be able to get up to the speeds required for the ramjet to kick in, and then eventually the scramjet.

Again, chemistry is your friend...it can span many gaps, especially when it results in a highly reactive display of energy.

Fine. But in this case, the designers of the SR-72 are supposedly working with Aerojet Rocketdyne in creating such a jet engine that will get them over what some call that "Mach 3 Chasm" -- i.e., a jet engine that can get them up to the necessary speeds for the ramjet to begin working.

But it will ultimately be the ramjet and scramjet that will allow the SR-72 to fly really fast. The trick is to get if flying sort of fast enough (relatively speaking) for the ramjet and scramjet to begin working.

I'm not sure if chemistry per se is the saving grace here, or if Aerojet Rocketdyne is using mechanical engineering tricks to do the job.

Whatever the solution (mechanics, chemistry, metallurgy, or whatever) that will allow the SR-72 turbojets engines to be able to get up to the speeds required for the ramjet to work, Lockheed and Aerojet Rocketdyne seem confident it is a viable solution.

a reply to: Krakatoa

I bet like most dangerous things on this planet it's probably very pretty to see this chemistry in action.

That's a topic for another thread though. Why is it that most of the times if it's beautiful it's dangerous. Poisonous tree frogs, coral snakes... women.

originally posted by: BASSPLYR
a reply to: spaceman42

wonder if compressed air would work as a pre compressor cooler? Like hypothetically speaking use plasma blooms at specific places right in front of the inlet to act as a virtual inlet cowl compressing the air and cooling it before it goes into the intake? Combine it with New materials inside the turbine that are light and extremely heat resistant. Throw in some chemistry out the back. = really fast engine?

Speaking from only a limited knowledge in Aerospace Engineering from a year of studying the subject in the past and keeping up as a hobbyist, I would imagine that pre compressing and pre cooling the airflow before hitting the actual physical engine inlet and first stage compressors would be a good start. The way that actually could be achieved is way beyond my current knowledge. Temperature would probably be the main limiting factor, but again just an amateurs guess.

originally posted by: BASSPLYR
a reply to: spaceman42

wonder if compressed air would work as a pre compressor cooler? Like hypothetically speaking use plasma blooms at specific places right in front of the inlet to act as a virtual inlet cowl compressing the air and cooling it before it goes into the intake? Combine it with New materials inside the turbine that are light and extremely heat resistant. Throw in some chemistry out the back. = really fast engine?

Well heck, hold on. Hypothetically put these modifications to the sr-71 power unit, and maybe ?

originally posted by: BASSPLYR
a reply to: Krakatoa

I bet like most dangerous things on this planet it's probably very pretty to see this chemistry in action.

That's a topic for another thread though. Why is it that most of the times if it's beautiful it's dangerous. Poisonous tree frogs, coral snakes... women.

Like this lovely here?

dang erous beauty

You might call her the Lady Of Green

a reply to: mbkennel

Aw Yeah!!! Green girls in Leather Bikinis. Always a good combo! Too bad you have to travel all the way to Orion to find one. Guess I can always try and convince my girlfriend to let me spray her green and dress her in leather. Wait I need a girlfriend first. Can you believe a guy like me is single? I'd like to see the equation that explains that Mr. Physicist.

It might be something like this.




Or this.


www.abovetopsecret.com...

Dont be daft we all know its the Aurora...
Blackswift like airframe with much modified Sr-71 engines to run "green" would be my bet.. = Sr-72