Test 1: (which Potassium Nitrate: Sucrose ratio is most powerful)
We tested 2 motors (21.5 mm diameter, 5 inches in length with 4 mm core and nozzle) :
- The First with a 75:25 ratio mixture(KNO3, C12H22O11)
- The Second with a 65:35 ratio mixture(KNO3, C12H22O11)
Results: The 75:25 ratio motor burned but generated minimal thrust and the 65:35 motor burned in a similar fashion however generated huge amounts more thrust.
In Conclusion we have found that the 65:35 ratio mixture is better as it produces more thrust per gram than the 75:25 mixture.
Test 2: (which design of motor is better, a core burner or an end burner)
We tested 2 motors (21.5 mm diameter, 5 inches in length with 4 mm core and nozzle :
- The First with a 4 mm core and nozzle
- The Second with a no core and a 4 mm nozzle
Results: The cored motor produced over 10 Newton’s of thrust for 1.5 seconds and the end burner produced negligible (50g) thrust for roughly 15-20 seconds.
In Conclusion we have found that core burners are more suitable for our model rockets as they produce a short burst of thrust to get the rocket off the ground. The end burner would not get the rocket off the launch pad and thus is not suitable for our current needs
Test 3: (which nozzle diameter produces the most thrust)
We tested 3 motors (21.5 mm diameter, 5 inches in length and with a 6 mm nozzle) :
- The First with a 6 mm nozzle
- The Second with a 7 mm nozzle
- the Third with a 8 mm nozzle
Results: All 3 motors produced similar amounts of thrust. The 6 mm nozzle motor produced 14.5 Newton’s of thrust, the 7 mm produced 10.4 N and the 8 mm produced 11.6N.
In Conclusion we have found that we need to do more testing on this area however it does seem that the smaller nozzle produced more thrust. Our next test may be to test a 4, 6 and 8 mm nozzle motors.
We have now reached the limit of testing this fuel type as we must abide by the laws and regulations to keep our work safe