%0 Journal Article %A Blomshield, Fred S. %D 2011 %I Begell House %K combustion instability, thrust oscillations, oscillations, pressure oscillations, solid rocket performance %N 6 %P 469-485 %R 10.1615/IntJEnergeticMaterialsChemProp.2012005612 %T RELATIONSHIP BETWEEN PRESSURE AND THRUST OSCILLATIONS %U https://www.dl.begellhouse.com/journals/17bbb47e377ce023,00f43b2a20d2c30f,0298e4e80333f97f.html %V 10 %X Solid combustion instability is the study of combustion and fluid dynamic coupling with the natural acoustic resonant modes inside the chamber of a solid rocket motor. Usually, it is expressed by peak-to-peak measurements of the internal acoustic pressure determined by high-response pressure transducers. These measurements, if done properly, are very precise. This combustion-driven acoustic behavior is well understood in terms of how it affects a motor's ballistics. However, rocket motors do not exist by themselves and are almost always part of a complicated system of components. These components include the warhead, guidance sections, thrust vector control, control surfaces, actuators, fusing, arming, data connections, and additional structure to hold it all together. The real question when dealing with combustion instability is what is the effect of the internal pressure oscillations on the system. From a systems perspective, the primary effect of interest is both mean and oscillatory thrust changes. These thrust oscillations can be very severe and lead to motor failure. Even with low levels of acoustic pressure oscillations there can be significant effects on the system. This paper presents various ways to approximate the thrust oscillations from a given pressure oscillation. Both analytical and experimental results show that the severity of the thrust oscillation can be considerably higher than the internal pressure oscillation. It will be shown that thrust oscillations tend to be higher later in the motor firing. Finally, some suggestions and guidelines are presented on how best to determine acceptable specification limits on pressure oscillations in a solid rocket motor. %8 2012-12-11