Large solid rocket motors can exhibit sustained pressure and thrust oscillations during the quasi-steady operative condition. These fluctuations are characterized by a frequency close to the first acoustic mode, or one of its multiple, of the combustion chamber. The origin of this phenomenon is the coupling between shear layer instabilities, and acoustic feedback, resulting from the destruction of vorticity by some geometrical features of combustion chamber, as port area variations or nozzle walls. In the present work, a quasi-onedimensional model for the analysis of solid propellant rocket motor aero-acoustic phenomena is described. The proposed model is derived formally from the Euler conservation laws and it is implemented into a code named AGAR (Aerodynamically Generated Acoustic Resonance). AGAR model is here applied to the P80 SRM, first stage of the European VEGA launcher. The demonstration test, P80 DM, exhibits four phases of pressure oscillations.
Pressure oscillations simulation in P80 SRM first stage VEGA launcher / Ferretti, Viviana; Favini, Bernardo; Cavallini, Enrico; F., Serraglia; DI GIACINTO, Maurizio. - (2011). (Intervento presentato al convegno 47th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit 2011 tenutosi a San Diego, CA nel 31 July 2011 through 3 August 2011) [10.2514/6.2011-6055].
Pressure oscillations simulation in P80 SRM first stage VEGA launcher
FERRETTI, VIVIANA;FAVINI, Bernardo;CAVALLINI, ENRICO;DI GIACINTO, Maurizio
2011
Abstract
Large solid rocket motors can exhibit sustained pressure and thrust oscillations during the quasi-steady operative condition. These fluctuations are characterized by a frequency close to the first acoustic mode, or one of its multiple, of the combustion chamber. The origin of this phenomenon is the coupling between shear layer instabilities, and acoustic feedback, resulting from the destruction of vorticity by some geometrical features of combustion chamber, as port area variations or nozzle walls. In the present work, a quasi-onedimensional model for the analysis of solid propellant rocket motor aero-acoustic phenomena is described. The proposed model is derived formally from the Euler conservation laws and it is implemented into a code named AGAR (Aerodynamically Generated Acoustic Resonance). AGAR model is here applied to the P80 SRM, first stage of the European VEGA launcher. The demonstration test, P80 DM, exhibits four phases of pressure oscillations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
