Aluminum combustion instabilities: Dimensionless numbers controlling the instability in solid rocket motors

This article is focused on the analysis of aluminum combustion dynamics, induced by acoustic oscillations, in solid rocket motors. dynamics expected to drive self-sustained pressure oscillations which can lead structural damages rocket. In order control this thermoacoustic instability, theoretical developments are presented paper highlight main parameters source. These new based a linear model source has been verified with numerical simulation previously published work. With some assumptions and reductions, clearly demonstrates that (i) depends 4 dimensionless numbers (Sherwood number, Stokes Strouhal flow number), (ii) if be split into two contributions (flame around an evaporating droplet end-dynamics), both have different tendencies, (iii) acceleration mean along motor leads instability. Under (aluminum model, or weakly nonlinear dynamics), these results make it possible instability motor.