For The First Time Ever, NASA Captures Images of Supersonic Shockwaves Merging in Air

Science Alert ^ | 7 MAR 2019 | CARLY CASSELLA

[amorphous]

Here's one of my favorite pics of Thrust SSC breaking the sound barrier.

Yep, that's a great picture, and it illustrates what I'm seeing even better. The shock-wave has to be traveling faster than sound for it to have such a perpendicular departure? No/little curvature in your pic either.

[Ol' Dan Tucker]

Look at the shock wave in your diagram. It's at a 45 degree angle at Mach 1, which is what it should be - sound waves traveling 1 for 1 from its source at Mach 1 (i.e., 45 degree angle).

But in the image posted by the OP, the waves are at least 80 degrees perpendicular to the aircraft! So what's up with the NASA image of two aircraft flying faster than the speed of sound?

First, it's just a diagram. the shock wave is exaggerated for effect. Shock waves develop perpendicular to the airstream. Since Thrust SSC was just at the speed of sound when that photo was taken, the shock wave is nearly 90 degrees. Since the jets are traveling at supersonic speeds, the shock wave is angled rearward.

Below is a shot done the same way that shows the bow wave.

Here's a web site that provides a simple explanation of the pressure wave generated by the airplane traveling through the air. (See: High-Speed Aerodynamics – Shock Waves)

[DUMBGRUNT]

Thank you!
That was good.
I like to see a bit of the ‘underlying form’.

From your link:

“The new cameras are digital, but the high resolution images they grab at 1,400 frames per second – more than 20 times the fastest setting on many personal cameras – can fill up the system’s available memory in just three seconds.”

[amorphous]

I'm trying to wrap my tiny brain around the perpendicular aspect. May just have to write a simple simulator or find one someone's already written, to help me visualize what's taking place.

Thanks!

[CJ Wolf]

Well. Technically they are computer generated.

[GOPJ]

WOW - beautiful...

[amorphous]

Found an online simulator:

oPhysics: Interactive Physics Simulations

https://ophysics.com/waves11.html

I get it now! :)

[amorphous]

The further an object travels at exactly the speed of sound, the more perpendicular the shock wave becomes due to sound waves expanding.