Chemical Kinetic Pathway Effects in Turbulent Reacting Flows
The Army is very interested in accurate simulations of combustion in devices such as rockets and gas turbines, Otto and Diesel cycle IC engines, scramjet engines, rotating detonation engines, etc.
The performance of weapons systems using these devices directly affect casualty/loss rates and the ability to win wars as well as procurement decisions and program costs. Accurate and computationally-affordable chemically reacting Computational Fluid Dynamics (CFD) is needed to design new, smaller, lighter, more efficient and less costly combustion systems and assess their operability before encountering costly problems.
Unfortunately, accurate modeling of turbulent combustion generally requires sophisticated and computationally expensive kinetic mechanisms and turbulence models to capture important turbulence-chemistry interactions.Happily, there is a new, efficient turbulent combustion modeling approach that can not only accurately capture the effect of turbulence on combustion heat release, but is also insensitive to the size of the chemical kinetic mechanism employed.This combustion model holds great promise in not only improving reacting flow simulation efficiency and accuracy, but also helping us understand the nature of the turbulence-chemistry interaction.Success in this effort will allow this approach to be used on a wide variety of turbulent combustion problems and is expected to be commercially valuable.
Other Reaction Systems Projects
The development of weapons that can travel at hypersonic speeds is becoming a high priority to the US Air Force. A key technology needed for the continued development of these propulsion systems is the ability to cool the combustor by flowing fuel through channels machined in the walls.
Aircraft and missiles capable of rapid global strike and reconnaissance must fly at hypersonic speeds to achieve their performance goals. Future air-breathing hypersonic aircraft and missiles are expected to be powered by supersonic combustion ramjet (scramjet) engines.
The surfaces of rocket engines are exposed to high pressure combustion products at temperatures up to 6000?F. Regenerative cooling can cause coke to form on the heat exchanger surfaces.
The development of new, robust, lightweight life support systems is currently a crucial need for NASA in order to continue making advances in space exploration, particularly in the development of Lunar outposts.
Reducing the allowable concentration of carbon dioxide (CO2) in spacecraft is a critical need for NASA.
Scramjet engines, which likely will provide the next generation propulsion capability, operate at extremely high temperatures and air velocities, conditions that are very difficult to reach in a laboratory.
Reaction Systems, Inc. has developed a new line of robust high temperature ceramic choked flow venturis for use in oxidizing and reducing atmospheres at temperatures up to 2700?F (1480?C).