F-15’s Shock Diamonds At Night And In Slow Motion-Absolutely MESMERIZING

Nothing Is As Picturesque As This.

A few weeks ago, the USAF managed to capture a really neat phenomenon. Often called shock diamonds (aka Mach disks, Mach rings and doughnut trails), they’re a common phenomenon but not one that we’ve ever seen so beautifully captured on camera.

First thing’s first. If you’re wondering, this footage was taken at the Mountain Home Air Force Base in Idaho. As part of an exercise of the 336th Fighter Wing, F-15 Eagles were taking off just a the sun was setting. As you can see, it’s quite a sight, especially the blue background perfectly contrasted their shock diamonds.

In case you want to feel really smart, here’s how you’d measure the distance of the first shock diamond from the nozzle “x = 0.67 D_0\sqrt{\frac{P_0}{P_1}}”

This brings us to a little lesson if you folks are interested. Shock diamonds appear “from a complex flow field and are visible due to the abrupt changes in local density and pressure caused by standing shock waves.” That’s quite a mouthful, but it’s basically excess fuel that increases temperature when exiting a nozzle ignites while passing through the a normal shock wave.

Check it out. It’s quite a spectacle.