Theoretical, Numerical and Experimental Investigation of Secondary Injection with a Novel Pyrogenic Pulser

In this paper, a novel pyrogenic pulser was designed both analytically and numerically and evaluated with empirical tests. The motivation of this study was the need for active control of the aero acoustic pressure oscillations by injecting the secondary flow into the solid rocket motor. First, in brief, pyrotechnic and pyrogenic pulsers have been introduced, and then analytical governing equations have been presented in three transient, sinusoidal and Hercules methods. In order to understand the internal pressure of the pulsar and its plume length, the injection flow field has been evaluated using the ANSYS-Fluent software with both 𝑘 − 𝜔 SST and 𝑘 − 𝜀 Realizable models both at ambient and motor pressure. After that, the design and manufacturing of the pulser hardware and the test process have been described. Finally, analytical, numerical and experimental results have been discussed. The results show that there is a good correlation between the transient analysis in theory and the numerical solution by the k-ω SST model and the empirical test data. In addition, pyrogenic pulsers design depends on various parameters of motor and pulser charge performance prediction. The quality of pulser charge bonding to its insulator and erosion of its throat path due to injection have an important role to obtain a desirable pulser mass flow rate and plume length.