| The objective of this study was to characterize the effect of various motor design parameters on pulse-triggered instability and provide a database for comparison with existing and future nonlinear theories.; Data from 45 motor-firings was evaluated in the time-domain. The stability rating of a motor configuration based on fraction of dc shift and wave strength, was not always consistent; the fraction of dc shift was judged superior. It was shown that oxidizer particle size distribution and the presence of a stability additive affected pulse-triggered instability. In addition, it was shown that instability tended to increase with pressure, that cylindrical grains tended to be less stable than star grains, that shorter motors tended to be less stable than longer ones, and that smaller motors tended to be less stable than larger ones.; A new analysis methodology was successfully developed for the frequency-domain. It was demonstrated that transverse pressure waves were always present during fully developed pulse-triggered instability, although modal content varied. In addition, evidence was found that indicated that these transverse waves were driven by the propagating shock wave and that, with the shock wave, they contributed to the increase in time-averaged pressure associated with pulse-triggered behaviour. |
