Effects of Cavity on Thrust Oscillations in Subscale Solid Rocket Motors

Model for Acoustic Induced Aluminum Combustion Fluctuations in Solid Rocket Motors

“…In that case, large-scale vortical structures are produced by interactions of the flow with solid protruding obstacles by changes of the propellant geometry at angles or in the boundary layer along the solid propellant itself. Pressure oscillations, driving high-thrust oscillations, result, in turn, due to vortex transport close to nozzle cavity [7][8][9], vortex ingestion in the nozzle [10,11], and vortex shedding [12,13].…”

Influence of Nozzle Cavity on Indirect Vortex- and Entropy-Sound Production

“…It is striking that, in theLP9 subscale model experiments with the combustion of nonmetalized propellant reported by Gallier et al [7], the self sustained pressure pulsation amplitude increases by an order of magnitude in the presence of a nozzle cavity as shown in Fig. 3.…”

“…For vortex driven self sustained pressure pulsations, the presence of a cavity around the nozzle inlet (as in integrated nozzles) has been demonstrated to have a major influence [1, 4,6,7]. Indeed, cold gas scale experiments of a scale model of the Ariane 5 SRM show that the limit cycle amplitude of vortex driven self sustained pressure pulsations is proportional to the nozzle cavity volume [6].…”

“…III. The results are also used to offer a new interpretation of LP9 subscale model experiments with the combustion of non metalized propellant [7].…”

Combustion Instability and Pressure Oscillation Numerical Simulation in a Solid Rocket Motor

“…In these simulations, following the ideas of Gallier-et-al 11 the large aft cavity, due to the presence of the submerged nozzle, may be responsible for part of the instabilities in the hydrodynamic calculation. According to Anthoine 12,13 an aft-cavity can produce significant acoustic power.…”