Characterizing the Dynamic Behavior of Novel Energetic Materials for Space Propulsion
Motivation
- To develop a commercially viable method of measuring burning surface admittances of high-energy-density solid propellants at high frequencies and pressures
- Solid rocket engines are prone to high-frequency combustion instabilities that cannot be accurately predicted
- Current measurement techniques lack the ability to measure instabilities above 2 kHz
- The inability to predict and measure instabilities requires that all rockets be built and tested at full scale
Approach
- Since combustion gases are weakly ionized, a large applied magnetic field induces voltage in sensing electrodes
- The measured voltage corresponds directly to combusting mass passing through the electrode plane
- To provoke instabilities, a piezo-electric actuator changes exhaust orifice area at 20kHz introducing large pressure oscillations
Results
- Magnetic and electrode circuit have successfully measured mass-flow corresponding with pressure oscillations
- Experimentation is commencing on different propellants with known instabilities
