Development of Demonstrably Predictive Models for Emissions from Alternative Fuels Based Aircraft Engines
WP-2151
Objective
Domestically obtained alternative fuels can not only provide energy security but also can reduce the environmental impact of burning hydrocarbon fuels. However, the diverse sources from which alternative fuels can be derived leads to considerable uncertainty regarding the performance and emissions in aircraft engines. Predictive computational tools can significantly reduce engine design time for a variety of fuels leading to substantial cost benefit to the Department of Defense (DoD). Unfortunately, due to the complex physical and chemical processes that generate soot and NOx in these engines, currently available models for these pollutants are incapable of providing acceptable levels of accuracy.
The objective of this project is to develop demonstrably predictive computational tools for soot and NOx emissions from alternative fuel combustion.
Technical Approach
A novel experiment-driven model development strategy called the search-and-destroy (SAD) approach will be used to minimize errors in modeling emissions. Fundamental kinetic models will be developed for soot including detailed soot precursor evolution for alternative fuels, soot nucleation and surface growth, and surface oxidation processes. Detailed models for soot evolution and NOx formation in targeted alternative fuels will be developed in the context of the large eddy simulation (LES) methodology. This method will incorporate the interaction between soot and gas phase turbulent combustion, as well as soot-soot interactions. Further, the influence of soot-based radiation on NOx evolution will also be modeled. Using the SAD approach, a suite of experimental measurements will be developed to validate individual models and their interactions in the LES context. Experiments of jet-flame in crossflow will provide detail on joint measurements of soot volume fraction and gas phase velocity, temperature, and a mixture fraction. Mean NOx concentration will also be measured. The enhanced SAD validation approach will point out the source of modeling error. Based on this information, more targeted experiments with altered operational conditions will be carried out.
Benefits
The fundamental kinetic modeling of pollutants will provide insight into the formation mechanisms that can be used to design better alternative fuel blends. The comprehensively validated computational models can be used directly for simulating aircraft engines burning alternative fuels, and the experimental data can be used for future model development and validation. (Anticipated Project Completion - 2015)
Points of Contact
Principal Investigator
Dr. Venkatramanan Raman
The University of Texas at Austin
Phone: 512-471-4743
Document Types
- Fact Sheet - Brief project summary with links to related documents and points of contact.
- Final Report - Comprehensive report for every completed SERDP and ESTCP project that contains all technical results.
- Cost & Performance Report - Overview of ESTCP demonstration activities, results, and conclusions, standardized to facilitate implementation decisions.
- Technical Report - Additional interim reports, laboratory reports, demonstration reports, and technology survey reports.
- Guidance - Instructional information on technical topics such as protocols and user’s guides.
- Workshop Report - Summary of workshop discussion and findings.
- Multimedia - On demand videos, animations, and webcasts highlighting featured initiatives or technologies.
- Model/Software - Computer programs and applications available for download.
- Database - Digitally organized collection of data available to search and access.