Understanding Shock Waves in Aerospace Applications

Рет қаралды 124,793

ESG PEV Spring 2015

Күн бұрын

David Sherwood
Created 5/3/15
This educational video is a student production of MIT's Experimental Study Group with assistance from the Department of Aeronautics and Astronautics. The purpose is to provide an exciting and interesting introduction to shock waves and their applications in supersonic flight for individuals at the undergraduate level.
With assistance from Professor David Darmofal, I introduce the concepts behind shock wave formation and delve into the difference between the three main types of shocks. Placing this analysis in the context of aircraft design helps students draw conclusions and hopefully sparks their interest about this crucial
topic.
For Additional information visit MIT OCW Aerodynamics:
ocw.mit.edu/courses/aeronautic...
Soundtrack - Kevin MacLeod (incompetech.com/wordpress/auth...)
SR-71 Animation - TechLaboratories ( / @techlaboratories )
Traffic Animation - Andrew Marr (kzfaq.infoUCn2lg...)
Aircraft footage courtesy of Tails22 ( / @tails22x )
Special Thanks to Dave Custer, Graham Ramsay, and David Darmofal

Пікірлер: 81

@najeebrazeq4807 8 жыл бұрын

I learned more in this 8 minute than in the 4 lectures with prof

@233kosta 7 жыл бұрын

Your professor isn't very good then

@banama1758 5 жыл бұрын

bullshit

@backandforthpoet1612 5 жыл бұрын

maybe you should put ypur phone away during lectures

@nutritionfacts6429 5 жыл бұрын

you are wasting 40K of tuition for something that you can get from youtube, dear stranger if you think this guy can provide better education. oh i forgot, you need the paper :P

@rudhdamshende8696 3 жыл бұрын

True brother. I have Test tomorrow. Pray for me 🙏🏻😂

@MrClijun 3 жыл бұрын

5:16 I don't remember the that the velocity downstream (after) the shock increases higher than the upstream (before) the shock, it's actually the opposite. from what I studied is the velocity component parallel to the shock will be the same before and after an oblique shock, but the velocity upstream will make an angle (Beta) with the shock, and downstream will make an angle (Beta - Theta) which causes the component normal to the shock of V2 will be less than its counterpart in V1, which make the magnitude of V2 less than V1

@professorcuppoletti5336 2 жыл бұрын

Yes, this is correct. I also realized that this video incorrectly states that the air velocity "speeds" up through oblique shocks and that oblique shocks have "little effect on drag". This is incorrect. Oblique shocks create less drag and flow deceleration than normal shocks or bow shocks, but the Mach number always decreases across an oblique shock. For a normal shock the Mach number after the shock must always be subsonic but through an oblique shock, supersonic flow can be maintained, but the Mach number will still decrease.

@watermenlon3617 Жыл бұрын

that is true, the velocity of the air only speeds up at convex corners which creates expansion waves. the complete opposite of oblique shockwaves. expansion waves are often referred to as the antithesis of oblique shock waves.

@samspade8612 11 ай бұрын

Best explanation of Shock Waves I've ever heard or seen. Bravo!

@vikrantvijit1436 2 жыл бұрын

Superb conceptual representation of knowledge based Shockwave phenomena, principles and patterns surfacing design decisions focused on applications areas.

@WorldEagleKW 6 жыл бұрын

Great video, short and concise explanation!

@firestorm734 5 жыл бұрын

This video is absolutely fantastic!

@hakeemnaa 2 жыл бұрын

2:30 thanks always relate what you understood to something you know and you will never forget

@jithu9484 2 жыл бұрын

What a superb video. So helpful

@villiamo3861 Жыл бұрын

Superb video. Thank you.

@ethanloewenthal6528 5 жыл бұрын

6:50. My understanding is that wing sweep is used to avoid shocks all together, not create oblique shocks instead of normal shocks.

@Kebab_with_extra_garlic_mayo 4 жыл бұрын

thats true as it increases the percieved chord of the wing, I'm suprised by how many errors this video has

@peterterwilliger8190 4 жыл бұрын

@@Kebab_with_extra_garlic_mayo The bad part is that he sounded so very sure of himself. Even worse, some people will believe him without checking his figures .

@theboatcheat1204 2 жыл бұрын

I think you might be thinking of the sweep being used to keep the wing leading edge behind the oblique shock from the nose. He was referring to an oblique shock on the leading edge of the wing I think - but still don’t agree that it accelerates the air!

@Thompsonje 6 жыл бұрын

Terrific presentation for understanding shock waves.

@salvatorelucanieddu3417 4 жыл бұрын

many things in this video are wrong

@CharlesVanNoland 2 жыл бұрын

@5:40 I know I'm 7 years late but this diagram of the engine doesn't take into consideration that when it's in flight the cone lifts up straight. It is pointed down as a side-effect of the spring loaded mechanism that causes airflow to retract it to optimize compression on air intake - and when it retracts it straightens out and no longer points downward. The downward slant of a stationary SR-71 engine cone is just a side effect of the retraction mechanism. It's basically just dangling out there when not cruising through the sky.

@WildBillCox13 4 жыл бұрын

Fascinating. Thanks for posting. Liked and linked.

@flyworldwide8961 3 жыл бұрын

Best explanation ever thank you.

@Fickoch 2 жыл бұрын

I have to say it… all this talk about waves and your audio for this video is killing my synapses!!!

@paolomaldini3082 4 жыл бұрын

Sorry you were mistaken about oblique shockwaves. M2T1, P2>P1 and rho2>rho1

@andreamarchionni2560 8 жыл бұрын

This is a very simple but amazing way to demonstrate this phenomenon

@rajveerramesh956 5 жыл бұрын

I LEARNT MORE OVER HERE THAN MY ACTUAL CLASS THANK YOU!!!!!!!!!!!!!!!!!!!!!!!

@salvatorelucanieddu3417 4 жыл бұрын

everything is wrong here dude

@sujangowda6230 5 жыл бұрын

Good explanation

@womineer 8 жыл бұрын

@6:34 Shouldn't it be M>1 not M>0 for supersonic and vice versa for subsonic?

@abhishekverma1422 8 жыл бұрын

ya it should be M>1

@johno9507 Жыл бұрын

I remember my aero engineering instructor telling us after we had just studied subsonic aerodynamics to forget everything we just learnt as supersonic aerodynamics is completely backwards.

@ManualMaestro 5 жыл бұрын

4:46 looks like the notation on theta and beta is reversed

@adnenmez 6 жыл бұрын

5:15 you should revise that statement

@gerardoespino4382 5 жыл бұрын

I agree, I believe M1>M2. Per my understanding, through an oblique wave, M2 will still be supersonic, but lower than M1. Good video though.

@SergioHidalgoAero 5 жыл бұрын

@@gerardoespino4382 it dependes on the angle of the shock wave and on the M1, there is no a general way to say " After the oblique shock wave the air is always subsonic"

@varun3681 4 жыл бұрын

Can u explain that part im confused

@MrClijun 3 жыл бұрын

exactly!

@Burrahboy 8 жыл бұрын

Thank-you, concise and interesting.

@alexrosellverges8345 5 жыл бұрын

Really good video, thanks!

@fulmen67 5 жыл бұрын

Oblique shocks decelerate the flow. The expansion waves are the oblique waves which increase the mach number instead.

@ethanloewenthal6528 5 жыл бұрын

3:50. Almost all of that is a "mach wave" traveling at the speed of sound. Only the area very near the ball is a "shock wave" traveling greater than the speed of sound, i.e. with the ball.

@erinlucassen 3 жыл бұрын

At 6.55; "swept wings such that normal shocks behave like oblique shocks" is quite a glaring mistake. But other than that thank you for a very informative video!

@pureawesome01able 6 жыл бұрын

Very informative video, although there are slight errors, overall the video is very helpful

@LordBagdanoff 2 жыл бұрын

Why does the bigger fan suck more air and becomes slower in speed?

@MrGonerman 4 жыл бұрын

oblique shockwave decrease the Mach but is still supersonic please correct this video

@jonnyueland7790 2 ай бұрын

The expert in the first part, soundwaves/pressurewaves? Dont go faster than the wing they are simply just pushed out of the way.

@dennywey9816 3 жыл бұрын

Have to point out another mistake. Supersonic means faster than the speed of sound, i.e. the speed at which mechanical wave propagates, NOT the speed of air molecules. This is a common misunderstanding

@comradelevothyroxine5133 3 ай бұрын

this guy still alive?

@427SuperSnake1 6 жыл бұрын

That F-22 was not supersonic...

@peterterwilliger8190 4 жыл бұрын

427 SuperSnake1 Thank you, Yes, it was just loud .

@thethirdman225 4 жыл бұрын

Sound edit.

@benmax1295 3 жыл бұрын

thumbnail shows this guy was literally shocked

@Kebab_with_extra_garlic_mayo 4 жыл бұрын

this vdeos should be taken with some grains of salt, lots of simple errors here

@MrFraGal 6 жыл бұрын

This viedo is full of big mistakes. M

@gamersvalley 4 жыл бұрын

It's actually 0.3

@139skylab931 3 жыл бұрын

@@gamersvalley M=0.3 is a boundary of compressible/incompressible flow

@crimsonwreb3132 3 жыл бұрын

Great video, it has some mistakes like the comment says but if the one watching has some logical thinking he will easily see that it’s a mistake. The biggest one that can misdirect people is the fact that you say the flow will accelerate past oblique shockwaves, this isn’t true. Airflow always decelerates with the encounter of a shockwave!!!