Hybrid Rocket Motor Aerospike Nozzle Tests

This is a combination of 3 test firings of an Aerospike nozzle for my Senior Project in Aerospace Engineering from California Polytechnic State University in San Luis Obispo.

The test bed hybrid uses gaseous oxygen, GOX, and a 2" dia Plexiglas tube as the solid fuel. The Oxygen is at 100psi.

The first test run was not choked, which was expected for the throat area is ~10 times greater than what the ideal area should be. The ideal gap between the spike and the compression cowl needed to be .003", yes, 3 thousands of an inch. However, if this were too small, this could produce a thermal choke well in front of the actual physical choke, which would reduce the performance of the rocket. I machined the compression cowl to have a gap of .053" instead. This would have allowed me to re-machine it smaller to maximize the thrust of the rocket.

I planned to fire the test for only 10 seconds, however I got distracted and allowed it to fire for 20 seconds, 2-3 seconds shy of turning the two piece nozzle into 3 or more pieces, that's what all the sparks are at the end.

This nozzle was machined out of 4140 Chrome-Molly. What took over 32 hours of CNC machining only took 20 seconds to destroy.

The second set of fires is with the newer nozzle design which reduced the stagnation zones that burnt up the first nozzle. As you can see, this one produced over twice as much thrust than the first nozzle, this one was machined to have a throat gap of .013" which may have over choked this nozzle which leads to this being thermally choked which may explain why you can't see any fire out the end. However, it is a reusable aerospike nozzle. Thanks for looking.

Now you know why they call this rocket science.

Видео Hybrid Rocket Motor Aerospike Nozzle Tests канала ragobgar