How the SR-71's Engine Worked

Credits:
Producer/Writer/Narrator: Brian McManus
Head of Production: Mike Ridolfi
Senior Editor: Dylan Hennessy
Research Assistant: Josi Gold
Cinema 4D Animator: Eli Prenten
Sound and Production Coordinator: Graham Haerther
Thumbnail: Simon Buckmaster
Head of Moral: Shia LeWoof

[romain.guillaume]

The only issue which is not mention in this video is that these types engine do not work at low speed. They already need a super sonic airflow to work properly. THIS is why the J58 engine is so special : it works as a turbo reactor at low speed to progressively become a ram engine (or statoreactor) at supersonic speed.

EDIT: thanks for the clarification brought in the comment. Indeed, at no point this engine work like a ramjet, even though there are several engine configurations optimized for subsonic and supersonic speeds.

[UnbarablePain]

Obviously not enough time to put in a short but the resson the Ram Jet works is because the inlet cone forces the oncoming air into a smaller path, raising the pressure. From Bernoulli's principle, as pressure increases velocity decreases, and vice versa. The inlet cone can change position to keep the supersonic shockwave from its leading edge out of the combustion chamber as the speed increases.

[williamkennedy]

The "cone" is a moving part, it moves forward and back to adjust for conditions. The movement was controlled constantly via a mechanical computer. It's hard to imagine is a monumental understatement.

[MissJean]

When I lived in Okinawa, at Kadena AFB, the Habu (SR71) engine test area was on the main road around the airstrip. They would stop traffic during testing. It was very loud.

The SR71 is incredible to see at take off. Awesome aircraft.

[mathiask]

Keep in mind that this jet was one of the last ones to be completely designed by hand

[TheSleepSteward]

It’s insane how these engines don’t just explode. I mean I know they are kinda exploding but you get what I mean. The entire engine going kaboom. The Cold War era had some of the coolest tech dude.

[smeariestline]

Coolest plane ever. I can’t wait to buy one

[timothy-bf]

I saw an interview with one of the engineers who worked on the engine. They achieved something like 99% efficiency with this design, almost double that of any other engine of the time.

[brainfart]

This made me excited, thinking you were doing another SR-71 video

[DirtCobaine]

Damn it always AMAZES me when I actually think about an engine and how the hell the first engineer to make one even could come up with it. And seeing the engineering behind this type of propulsion is insane. Like it’s actually magic.

[gabedarrett]

You should've mentioned that it was a combined cycle turboramjet engine

[idesofmarchUNIAEA]

These were on the drawing boards in the late 1950s. The first flight I think was in 1964. I am not an engineer, but one of my sisters husbands was a wing designer for Boeing. I think there is a golden ratio application to this, to maximize airflow. Just a thought.
golden ratio, also known as the golden number, golden proportion, or the divine proportion, is a ratio between two numbers that equals approximately 1.618. Usually written as the Greek letter phi, it is strongly associated with the Fibonacci sequence, a series of numbers wherein each number is added to the last.

[ThexBorg]

The shock cone also uses perforations for the Laminar Effect. This allows the air to travel faster over longer surfaces. The lower pressure inside the shock cone is vented out of the top of the nacelle

[krakhedd]

Even in a short like this, it's criminal to neglect to mention the J-58's extendable cone, and its purpose; that's actually rather the most-unique and -impressive thing about it

[truthhadoken]

Don’t forget that the inlet moves forward and backwards depending on speed to compress the supersonic properly also

[themindset]

That is such a simple and brilliant explanation

[orangecounty]

This is the most simplistic beyond the simplified method of explaining the way these jet engines work. That’s like saying how does a tire work on a car, oh, it just spins.

[tervikur]

Fun fact thees engines were basically upgraded vertion of an old engine developed by French army. This plane was called Leduc 022 but couldn't get over mach one bc of the lack of knowledge we hade on aerodynamics physics back then. Hope that helps

[FlamingToaster]

A ramjet, as you could probably guess from the name, relies on ramming the jets

[sbrunner]

So did the SR71 have a ram jet or not? What the heck.