Award Data

ABSTRACT: Combustion instability (aka thermoacoustic instability) is a significant issue in propulsion systems including augmentors. Oscillations can increase heat transfer to walls 10 fold and cause vibration damage to the propulsion system and the surrounding system. This damage can occur very rapidly. Combustion instability (CI) is challenging to design for due to the complex interactions betw ...

ABSTRACT:The SBIR primary objective will be to show the feasibility of advance modeling for simulating and predicting the surface corrosion leading to fatigue damage. This capability will produce early-life stage models which will enhance state of the art corrosion analysis. The SBIR conceptual modeling method must address small damage, in a corroded microstructure for fatigue crack growth. The me ...

ABSTRACT:The damage tolerance approach is used widely in the aerospace industry and has a physics-based foundation in fracture mechanics. The fatigue crack growth rate can be determined by calculating the SIF (stress intensity factor) and knowing empirically derived material parameters. Similitude is achieved for different loads, different crack sizes, and different crack shapes. The down side to ...

Building upon the successful use of the Universal Combustion Device Stability (UCDS) process to resolve NASAs Ares I thrust oscillation issue, the proposed effort will optimize UCDS for application to the oxygen-rich staged combustion (ORSC) cycle under development by the Air Force.  This will be accomplished by refining the way UCDS models the propellant injection into the chamber.  By providin ...

Current aircraft design approaches incorporate the use of many high fidelity models for point solutions of individual disciplines. Sophisticated model integration techniques are not yet readily available and a significant amount of individual discipline stovepiping exists. Individual handoffs of point solutions between disciplines often results in repeated individual data interpretations.  These ...

The proposed approach will build on existing probabilistic micromechanics model for failure analysis to include gradient microstructures. This effort will develop physics based damage models for the gradient microstructures focusing on complete damage evolution of the transition zone between the bore (fine grain) and the rim (coarse grain). The mechanisms considered will include 1) fatigue, 2) cra ...

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