Solid propellants based on potassium nitrate (KNO 3) and sucrose are widely used in rocketry, because they are inexpensive and easily obtainable compounds and also generate high specific thrust. In this study, the performance of propellants based on a mixture of 65 wt% KNO 3 and 35 wt% sucrose, named KNSu, was evaluated.Aluminum waste particles were loading at 2.5 wt%, 5 wt% and 7.5 wt%. Aluminum was used as a powder with an average particle size of 35 μm. Rocket engines were developed and the thrust versus time curves obtained for the samples studied. The results showed that the utilization of 5 wt% caused a 30% increase in both the specific impulse and the average gas ejection velocity when compared to KNSu. The incorporation of 2.5 wt% and 7.5 wt% caused a reduction in the specific impulse and other properties evaluated when compared to KNSu. Based on the results obtained, it is possible to state that the insertion of aluminum waste from the metalworking industry may contribute to the increase of the performance of rockets that use KNSu as a solid propellant.

The purpose of this work is to present the development of a static test bench for amateur rocket engines. This bench has electronic load cell assembled with four calibrated springs in order to measure the impulse and predict the rocket thrust with different dimensions of combustion chambers, nozzles and new kinds of fuel for amateur rockets. This static test bench has a vertical assembly projected in SolidWorks ® , and a computer interface using the LabView ®. The bench was tested using commercial rocket engines from C class, that must presented a total impulse of 5.01-10 N.s. The tests were done in triplicate. The results of thrust (2.41 ± 0.07 N) and total impulse (6.02 ± 0.29 N.s) are in agreement with others values from the literature. The bench demonstrated to be safe and the obtained results are satisfactory for test rocket motors with a total impulse lower than 10 N.s.