Use of modern modelling technologies to master the dynamic behaviour of solid rocket motors

Paper number

IAC-08.C4.2.12

Author

Mr. Alain Mercier, Snecma Propulsion Solide, France

Coauthor

Mr. Dominique Ribereau, Snecma Propulsion Solide, France

Coauthor

Mr. Olivier DiFrancesco, Snecma Propulsion Solide, France

Coauthor

Mr. Jean-Claude Tauzin, Snecma Propulsion Solide, France

Coauthor

Mr. Cedric Rey, Snecma Propulsion Solide, France

Coauthor

Mr. Thierry Pevergne, Snecma Propulsion Solide, France

Year

2008

Abstract

The development of modelling techniques has reached a point where the dimensionning of the solid rocket motors to static loads is well mastered throughout different countries. The engineers have now at their disposal numerical models well correlated to experiment and accurate enough to optimise their design in a satisfactory extent. Modelling is now used for both performance and mechanical predictions, allowing a full coupled optimisation of the motor. As a gain, the development duration and cost have been significantly lowered by the reduction of the necessary development and qualification tests. 

Nevertheless, some part of the motor behaviour is still observed during the tests although having some significant impacts on the use of the motor in the launcher system behaviour. Generally, the dynamic loads induced by the motor ignition or combustion are still recorded during the tests and do not allow to optimise the motor design in the way of reducing their impact onto the payload.

Snecma Propulsion Solide has oriented the evolution of its modelling techniques toward the mastering of the prediction of these dynamic loads in order to better take into account their impact on the system earlier in the development phase.

First, some effort has been put to the predictions of the ignition transients. Aerodynamic models have been developed to describe the pressure rise in the motor and study its sensitivity  to parameters like pressurisation (pressure and gas type) and igniter performance. Correlation of test results to models are presented in this paper. 

Subsequently, the effort has been set onto the integration of these models into the mechanical modelling of the motor. Coupling of the two numerical codes has been performed in order to reach a full integrated modelling of the ignition transient. This coupling allowed to better understand the parameters influent on the loads generated during the ignition. The methodology which has been developed as well as the correlation to full scale results are presented here.

This publication is still pending french autorities agreement.

Abstract document

IAC-08.C4.2.12.pdf

Manuscript document

IAC-08.C4.2.12.pdf (🔒 authorized access only).

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