ATA ENGINEERING, INC. — National Aeronautics and Space Administration STTR Phase I: T1.02

Description

Mitigation of dynamic combustion instability is one of the most difficult engineering challenges facing NASA and industry in the development of new continuous-flow combustion systems such as the combustion chambers in liquid-fueled rocket engines (LREs). Combustion instabilities are spontaneous, self-sustaining oscillations that tie the combustor acoustics to the combustion reaction itself. These oscillations can lead to a wide range of problems from off-design performance to catastrophic failure. Efforts to predict instabilities at design-time is hindered by the complex, multi-physics nature of the acoustics and chemistry, typically requiring multiple iterations of time and resource intensive system prototyping. The proposed Phase I STTR project aims to develop a simulation framework that will enable accurate, design-time prediction of instabilities. This framework will leverage the capabilities of Loci/CHEM for massively parallel, multi-physics flow simulations to generate low-order, independent models of combustion and acoustic response to perturbations. By solving for simultaneous solutions of these low-order perturbation models, it will be possible to numerically map the acoustic modes of the system to their stability characteristics, providing a means to predict instability. Phase I will develop critical additions to Loci/CHEM's combustion modeling capabilities, develop the appropriate acoustic models, develop a test plan for experimental validation of the combustion model, and conclude with a proof-of-concept demonstration of the full framework. In Phase II, an experimental campaign will be carried out to validate the combustion modeling tools developed in Phase I and augment the simulation framework with multi-phase modeling appropriate for full-scale LRE combustion chambers.