A Software Toolkit to Accelerate Emission Predictions for Turboelectric/Hybrid Electric Aircraft Propulsion

This product addresses NASA Aeronautics Research Mission Directorate (ARMD) core needs for enabling safe and reliable operation of next-generation (e.g., N+3 generation and beyond) ultra low-emission power turboelectric and hybrid electric aircraft propulsion, where gas turbine engines will continue to play a critical role. With increasingly stringent environmental regulations, reduction of emissions, including NOx, remains a key concern, in particular for larger aircrafts operating in the mega-watt range. This product also addresses core needs of NASA?s vision for next-generation aircraft systems with hybrid integrated wing/body systems that feature significant improvements in engine performance, emissions and noise reduction. Since low-emission gas turbine engines/generators tend to operate at fuel lean conditions near the flame lean blow-out limit while avoiding the occurrence of combustion instability, a detailed understanding of flame dynamics and unsteady combustion effects is required to develop fuel-efficient, low-emission, stable combustor designs. In this regard, advanced CFD design tools can provide fundamental physical insight that is difficult or cost-prohibitive to obtain experimentally. Given the inherent modularity of the LEM-CF approach, interfacing with the National Combustion Code (NCC) will provide NASA with a powerful design support tool.

The commercial market for this product includes the broad aerospace, power-generation and defense industry. The primary driver for the commercial market for this product is represented by commercial aircraft gas turbine engines. The proposed software toolkit directly addresses the resulting increased demand for high-fidelity design tools that accurately characterize emissions and unsteady combustion effects and will benefit commercial gas turbine OEMs (both commercial and military) by providing them with a powerful and tractable supplement to minimize the need for experimental testing. Other applications encompass power-generation turbines and internal combustion, HCCI and diesel engines, e.g., using engine recirculation (EGR) devices to mitigate harmful NOx production. DoD applications include the design of gas-turbine engines, scramjets, pulse-detonation-engines (PDEs), augmentors, UAVs propulsion systems and rocket engines. Of particular relevance is the Army single fuel policy mandate to use jet fuel in ground vehicle diesel engines to simplify the supply chain logistics in the battle space and to strengthen domestic energy security. Also noteworthy is the DoD growing interest in fuel blends with alternative or renewable fuels, e.g., synthetic paraffinic kerosene or camelina-derived bio-fuel, as an acceptable form of "drop-in" fuels. More »