This test will use a propellant formulated from 65% KNO3 (prilled), 32% Sugar, and 3% Magnesium shavings. This is more just out of curiosity than anything else. I suspect the Mg shavings will make for a bright flame. Strand burn tests indicated a burn rate similar to standard sugar propellant using powdered KNO3, so my T-2 motor should handle the propellant fine. You can see the test results of the propellant strand tests at my Experimental Propellants 2 page.
I needed to make some test grains when I cast the propellant, and I ended up mixing too small of a batch. So the grains are a little shorter than would normally be used in the T-2 motor. The grains totaled just under 1 pound of propellant. Had the grains been full length an additional 16.46 grams of propellant would have been added to the propellant weight.
Grain 1) Length 5.125"; Weight 223.7 grams
Grain 2) Length 5.25"; Weight 230.9 grams
Burn Time: 1.267 seconds
Total Impulse: 137.125 pound seconds
Isp: 138
Maximum Thrust: 297.47 pounds
Here is the thrust time curve chart for the test.
Here is the motor at full thrust. The white smoke hides the flame, which is also white.
Here at the tail end of the burn you can see some of the white flame.
This was an interesting test. A recorded Isp of 138 is very good. Burn time of 1.2 seconds is faster than the propellant without the Mg, but still relatively slow. The flame was white, but hard to see with all the white smoke. Software analysis of the propellant gives me a combustion temperature of 2,658 F., that's pushing the limits for a steel motor with no thermal protection, but should should still be within safe limits. The C* is 2,930.7 and the Isp is 148.4. After one static test, it seems Mg may be a good additive for sugar propellant, I can't see any real draw backs at this time.