Supersonic Nozzles - What happens next will SHOCK you!

In this video, I want to try and convince you that supersonic nozzles aren't some magical, counter-intuitive device that can only be explained by mathematics.

I've done my best to provide what I think is a good intuitive explanation. It does require a basic knowledge of normal shocks and oblique shocks, but hey, I didn't say it was easy!
In any case, I briefly discuss shocks as well.

Enjoy!

#supersonic #nozzle #rocket #propulsion #shock #shockwave #machdiamond #chokedflow

[mubashirahsan]

BEST FUCKING VIDEO EVER, SAVED MY PROPULSION MID TERMS

[TastySlowCooker]

If I understand correctly you’re saying the reason we have traffic jams is because our speed limits are below the speed of sound

[jonahgimmi]

I'm a freshman in mechanical engineering, looking to go into propulsion, and even though I have heard some of the beginning stuff and some of the later stuff went over my head, this was great! I am absolutely sure I will be coming back to this in the future as a visual aid. Keep up the good work man!

[mxtt]

Ahhh at last, this concept is no longer counterintuitive to me. You sir have helped me greatly in my fluid dynamics exam. Hats off to you from aus 🇦🇺

[alecv]

Hello Lyle, kudos for this interesting and very well done video. Keep it up!!

[kapilsharma-xzos]

Oh man thank you for making me understand about CD nozzles in compressible flow case and ..Most importantly, Pe and PA variations.

[josecarlosribeiro]

Congratulations Master for your beautiful presentation and interesting manter! I learnt so much! Thank's a lot and my best regards! Jacareí-Sao Paulo- Brazil.

[comment]

Great video and very pleasant Canadian accent.

[dhrumil]

It would be really helpful if you can discuss the method of characteristics part.

[ariebos]

Great explanation with very explanatory graphics. Many thanks. A question though: what are design parameters for a nozzle to create certain effects? E.G., if I wanted te create maximum shockwaves, regardless wat happens to the airspeed at the exit, what would that mean for the design of the nozzle?

[Goji-Moji]

The biggest question I have is just “how do you reduce the pressure at nozzle exit?” Does the air coming out of the nozzle play any part in this? I can certainly understand a pressure controlled room or environment, but I don’t think that’s really what’s meant or else it’d be kind of useless.

[CarlosAM]

"What happens next will SHOCK you"
...badum tss

[uninteressant]

Awesome explanation, especially the "supersonic particles interact with particles of the same speed" and normal/diagonal information sending. That makes everything much clearer.

I have a question: In rocket engines we accelerate mass to high speed in order to get a high impulse from them. But where exactly does the impulse exchange between the accelerated particles and the nozzle occur.

An as a bonus: How does this work in aerospike engines.


Normal Nozzles are inefficient when they are not expanding enough, leaving a pressure difference between inside and outside that also "adds" to the thrust (F=deltap*Area) but less than if it were perfectly expanded (assuming bell with no weight blabla). And the outgoing gas stream is not perfectly straight further hurting efficiency or is that already accounted for?

Anyways with aerospikes supposedly going around this problem, where exactly is the thrust exchanged on an aerospike, especially when it is in thinner atmosphere where the outgoing gas should pretty much look as "bad" as the traditional nozzle. (As in, expanding almost normal to the rocket axis as we know it from 1st stages in higher atmospheres)

Does the thrust exchange work beyond the nozzle? Probably not because the flow is supersonic, so does it exchange "diagonally" from the last part of the nozzle?

[JoseGonzalez-tdtv]

Thank you very much for sharing this with us. I was wondering whether this behavior may similarly occur for nozzles immersed in pressurized fluid-chambers or if the same effect is observable instead for inlet pressure increments for a fixed exit pressure. If immersed, What will be the conditions for the shock waves to happen within the surrounding fluid?

[paperclips]

Does YouTube also put cookies in my brain because I literally thought of this " ok the math says so but what's the reason for supersonic flow".

[loretacancela]

Hi! I'm currently designing a Nozzle for a CubeSat, I used MOC to obtain the design of the wall. I then passed it to ANSYS and i have an underexpansion effect which was expected if my ambient pressure is 0. So, I want to know how much I can expand the exit area to get the pressures to balance. I want to model this just like your video where I can have two charts and see the change in Mach and Pressure changing the velocity and exit area, what program do you use or what can you recommend for this. Thank you!

[chibuezendiokwelu]

I have a question, u mentioned that pressure at the exit nozzle must match the atmospheric pressure. So how do you reduce the atmospheric pressure. Also the part abt shock was a bit confusing

Looking forward to your reply

[wiictorr]

OMG THIS VIDEO SAVED ME IN HYPERSONIC Thanks from Brazil🟢🟡

[rat_king-]

tanh(x)for fluid supersonic.
cosh(x) for object driven in why?

[chibuezendiokwelu]

Hi I left a comment on your follow up comment looking forward to ur response