Dynamic ICP® Pressure Sensors for Detection of Combustion Instability and High Intensity Acoustics

Rocket motor combustion instability is caused by pressure fluctuations and acoustic resonances in the combustion chamber, which may reduce engine performance, induce structural vibration, and possibly lead to catastrophic failure by a break-down of the thermal insulating boundary layer of the nozzle or other engine component. It is difficult to model in three dimensions during rocket motor design, even with modern computing power, and can be hard to eliminate. Dynamic quartz piezoelectric pressure sensors are available to assist design engineers in studying combustion instability problems. Piezoelectric ICP® (Integrated Circuit Piezoelectric) pressure sensors are rugged, hermetically sealed, and structured with acceleration-compensated quartz sensing elements that detect rapid pressure transients, pulsations, turbulence, noise, and spikes. Quartz piezoelectric pressure sensors monitor dynamic pressure while subjected to high static background pressure. ICP® output features on-board electronics to provide conditioned output signal and ease of use. Many physical configurations are available with various Aerospace Standard fitting sizes. This paper will discuss their effectiveness in helping a design engineer to study rocket motor combustion instabilities, and assist in proper sensor selection.