A linear model for the analysis of longitudinal fluid dynamic oscillations in solid rocket motors is developed and applied to the Ariane 5 boosters. The natural frequencies are corrected as proposed by Culick in order to account for the effects of mean flow, mass addition from the burning grain, pressure coupling, nozzle admittance, and internal geometry of the combustion chamber. In segmented solid rocket motors, the main driving source of acoustic oscillations is often represented by the coupling between the vortices shed by the inhibitors at the intersegments and the acoustic field in the combustion chamber. This interaction is analyzed using Flandro's model, which provides the vortex-related contribution to the amplificationldamping of the acoustic oscillations. The natural acoustic frequencies are considered as known inputs for vortex development in the shear layer, which is described by means of classical linear stability theory of parallel flows. The risk assessment of vortex-inducedfluid dynamic instabilities in a small scale and full size configuration of the Ariane 5 boosters is carried out for the leading modes at several burn times. Model predictions are in good agreement with the available experimental results for the scaled configuration.
|Titolo:||Linear Analysis of Vortex-Shedding Induced Longitudinal Oscillations in Segmented Solid Rocket Motors|
|Anno del prodotto:||1993|
|Appare nelle tipologie:||4.1 Contributo in Atti di convegno|