Investigating the effective stress function algorithm for the thermostructural analysis and design of liquid rocket engines thrust chambers

Abstract

The thermostructural behavior of a regeneratively cooled thrust chamber for aerospace applications is strongly non-linear as plastic and creep phenomena come into play. Indeed, the fuel combustion inside the thrust chamber generates high heat fluxes and, then, elevated temperatures are expected in the inner copper structure of the chamber which is made of cooling channels separating the hot gases from the coolant flow. Since the analysis of those non-linear phenomena requires the adoption of very complex and heavy numerical models, it is crucial to employ very efficient numerical algorithms such as the Effective Stress Function algorithm; such an algorithm allows to obtain accurate results in terms of stresses in finite element thermostructural analyses taking into account both plastic and creep phenomena. The aim of the current paper is, then, to demonstrate that the Effective Stress Function algorithm is well suited for the analysis of the thrust chamber providing accurate results in a reasonable amount of computation time. The numerical results obtained are very similar to those achieved with the classical approach adopted by finite element commercial codes with significant computation time savings.

Keywords:

• Creep
• effective stress function algorithm
• elastoplasticity
• thrust chamber
• thermo-mechanical analyses

Additional information

Funding

This research has been supported by the Italian Ministry of University and Research (MIUR), in the frame of the Hyprob Program.