Rocket Stability Design Tool Enhancement

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 providing a more precise representation of the actual conditions expected in ORSC engines, the fidelity of the UCDS predictions will be increased. The UCDS Process is the culmination of over 40 years of research into combustion instability phenomena and provides unprecedented insight into the dynamic environment in a combustion chamber.  With UCDS, it is now possible to accurately determine the oscillatory characteristics of propulsion devices, including pressure oscillation amplitudes and waveforms, unsteady surface heat transfer rates, and mean property excursions.  UCDS achieves this predictive capability by including all verifiable energy gain and loss mechanisms, and using only measurable or known parameters in the modeling. BENEFITS: The Air Force faces a steep and expensive learning curve if it follows the traditional develop path for the next generation hydrocarbon boost engines due to a lack of heritage and effective scaling rules.  However, UCDS offers the means to understand the complex dynamic processes at work in liquid rocket engine, and thereby eliminate the need for trial-and-error during engine development.  With the proposed refinements, it will be possible to achieve a more precise representation of a liquid rocket engine, thereby allowing UCDS to generate higher fidelity results.  This increased fidelity will aid in the development of the hydrocarbon boost engines. In addition to the Air Force hydrocarbon boost program, UCDS can be applied to practically any propulsion development program to eliminate the risks from combustion instability that all such programs share.  Since UCDS is built from a general formulation, it can be used on practically any combustion device, including rockets (liquid, solid, hybrid), turbojets (combustors, augmentors), ramjets, scramjets, combined cycle engines and so on.  As such, potential customers for UCDS services include government agencies, such as NASA, Air Force, Army, Navy, MDA, and DARPA, and propulsion system developers, such as ATK, Aerojet, Pratt & Whitney, Rolls-Royce, and many others.