HTP/PLA test on August 24, 2022
In this test there was a peak combustion pressure of ~140 psia with a linear decline to ~110 psia and a peak thrust of ~35 N declining to ~24 N. I believe the peak pressure and thrust were due to a brief plug of PLA in the throat. This is clearly visible in the video of the test. Ignition occurred in about 1.3 sec with a burn time of 3.0 sec. Although I had a really good thrust, my c* efficiency and thrust coefficient efficiency was ~74% and ~66% respectively. However, my O/F ratio was ~7.5, way to high (theoretical at 2.75). Theoretically, a high oxidizer to fuel ratio leads to poorer performance.