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.
|Titolo:||Pressure oscillations simulation in P80 SRM first stage VEGA launcher|
|Data di pubblicazione:||2011|
|Appartiene alla tipologia:||04b Atto di convegno in volume|