Analytical model for the prediction of pulsations in a cold-gas scale-model of a Solid Rocket Motor

Abstract

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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].…”

“…This approximation simplifies the source terms S g and S p in Eq. (8). When the droplet diameter reaches the critical value of D D r , the convective heat flux Q v around inert aluminum oxide particles is modeled as in Ref.…”

“…Combining the momentum conservation with the mass conservation of the droplet phase [Eqs. (5)(6)(7)(8)] leads to the following transport equation along the axial direction for the droplet velocity:…”

“…Combining the transport equations [Eqs. (5)(6)(7)(8)] for the mass of the droplet phase α p ρ p and for the number N p of particles per unit volume with the definition of the droplet diameter D given by Eq. (10) yields a transport equation for the droplet diameter in an Eulerian framework:…”

An analytical model for acoustic induced heat release disturbances from aluminum combustion in solid rocket motors

“…For larger motors, pressure oscillations are often due to hydrodynamic instabilities, as in Ariane 5 [2,3]. In that case, large scale vortical structures are produced by the interaction of the flow with obstacles or a change of the propellant geometry at angles, or by the solid propellant injection itself and the pressure oscillation production is mainly due to vortex transport close to nozzle cavity [9][10][11], vortex ingestion in the nozzle [12,13] and vortex shedding [14][15][16].…”