Unlucky Test #13!

Over the past two days there have been 7 unsuccessful attempts for Test #13. Is the number cursed? Our experience seems to indicate that it indeed may be! This is our first test of an entirely new 10lbf paraffin motor.


We've uncovered two major problems:

• Only getting gaseous nitrous oxide; no liquid
• Computer control malfunction

There's so much here that those two major problems are going to get their own entries. For now, here's some of our secondary issues:

Igniters:
We are out of igniters, and don't have all the supplies (namely nichrome) to make new ones. Our pyrogen is also running low. Thankfully the guy that made the igniters for WARRIORS II is still around, and is willing to make us a new batch when we have everything.

Paraffin:
This batch of paraffin didn't have any specifications associated with it as it is sold for arts&crafts purposes. We already have a large quantity of high-grade paraffin ordered and are just waiting for it to arrive.

Core diameter:
Our current grains have a 1/2 inch diameter bore. To speed up the nitrous velocity, we would need to reduce that to around 0.33 - 0.38 inches. To slow down the nitrous velocity, we would have to increase it, probably in the 0.6-0.7 range. Would changing it improve the motor's ability to ignite, and at what penalty to overall thrust?

Grain augmentation:

• Is it needed? (can the igniter do it on its own)
  
• Where should it be applied? (core, mixing chamber)
  
• What should it be? (kno3, standard AP solid composite, pyrogen, sorbitol/potassium nitrate, etc)

Additives:
Right now all our tests have been done with 2% (by mass) of lamp black / charcoal. This slightly suppresses the combustion. Should our tests next week still use this, straight paraffin, or have an accelerant added?

Timing:
Right now we have no idea what the best ignition sequence is for paraffin. The three options are:

1. ignition/delay/flow
2. simultaneous ignition & flow
3. preflow prior to ignition

Data Acquisition
On the plus side, the LabView interface is working great now. No buffer overruns, data can be displayed in realtime with high refresh rate, not all data has to be stored to the hard drive, etc. Its really slick now, and getting to the point where it may replace the linux laptop & perl script for the actual motor control. No, the outputs from the controller for event recording hasn't been completed yet -- I've been kinda busy with higher priorities.

We certainly have our work cut out for us!