super Sonic Rocket

Home built model that goes to mach 1.o in less than 15 seconds.
Watch the fins warp at top speed.

Category:

Howto & Style

Tags:

• rocket
• supersonic

[flyparks]

I don't think the fins are actually warping. I've flown a lot of r/c airplanes with video cameras on board, and on occasion vibration will make waves in the video. Besides, if the fins are aluminum, they would stay warped. Unless they are made by Rubbermaid!

[stuman1159]

That sounds right to me...I don't know exactly what the fins were made of...could've been some type of plastic.

[Blutarsky90]

what are the fins made of?

[stuman1159]

Aluminum

[r0ck3tsm0k3]

Wonder why the fins dont warp again as it comes back below transonic speed.

[stuman1159]

the parachute probably scrubs off a lot of airspeed.

[JetJockey87]

Sonic Boom would only be apparent to a ground observer. As the sound waves collect behind the object approaching the speed of sound they build up and when it surpasses the sound barrier is when you hear the boom, but you wont hear it if your in the object.

[PassionStone]

I'm guessing that the altitude/apogee was approx. 20,000' and avg speed during burn was 1000 fps, with a max speed of 1350 fps on final stage with max thrust prior to burnout. The fins remained motionless, suggesting it was 7075/T6 Al...not many synthetic materials could withstand that force. I would not be surprised if the tube was thin wall T6. The velocity, integrity, & stability make this a VERY impressive launch.

[mathmyster]

@flyparks 2 posibilities

1. Flutter, the aluminium fins are being elastically twisted (possible even with this amount of distortion) due to aero elastic effects

2. the density change due to the shock wave is causing a lensing effect which make the fins look bent. the "flapping" is caused by the movement of the shock wave forward and aft. as the rocket accelerates only way to tell would be to put strain gauges on the blades (and a DAQ on the rocket) or perhaps pattern matching from the ground.

[DuckHunt20]

@stuman1159 the fins warped because of the forces acting upon it, and reaching MACH 1, probably made out of some sort of fiberglass or plastic, or even metal. awesome rocket!

[Reptile789]

Ok really stunman the fins were made out of fiberglass. This is a Quantum Leap model rocket from Public Missiles. The fins were fluttering as they would call it since it is going well past mach. Its crazy to believe that they would even bend like that. Btw supersonic speeds are Mach 1.2 and up. Mach 1-1.19 is transonic

[superskullmaster]

@stuman1159 Not only do you not know that, you don't know that supersonic speeds are quite a bit over mach 1. More like 1.05 and up.

[molinobeer]

@JetJockey87

...just a correction in front and not "behind" the object. ;)

[zyoungson]

okay that was BLOODY COOL

[botagAD]

the warping fins are a bi-product of the type of camera recording sensor and vibration most likely from speed...take a picture of a rotating fan with your phone camera and you will see the same effect but in a still picture....

[ZenonDorinPower]

@stuman1159 There is no material that could warp so. It's the camera vibrating,maybe caused by passing the sound barrier.

[jmar1371]

For those that want to know... That is a PML Quantum Leap model. The fins are G10 fiberglass with a carbon fiber overlay. What you are seeing in the video is caused by the conversion process. Those fins didn't do that. They can't.