Objective

Engine companies use computational fluid dynamics (CFD) and empirical models to design low emissions gas turbine combustors (GTCs) burning JP-8 fuel. The models do a good job in estimating emissions trends for different GTC designs, but, for some emissions such as non-volatile PM2.5 (soot) and hazardous air pollutants (HAPs), the errors are so large they are not usually calculated. It is difficult to identify and focus on the cause of the errors because of the strong coupling between the chemical and physical (e.g., turbulence, fuel vaporization) processes, and the results published by independent researchers cannot be readily integrated into a uniform theory because of mismatched experimental conditions. These problems have been successfully addressed following a new approach in a SERDP soot science project (WP-1577). This approach has been so successful that a transition to a soot design model for JP-8 fuel could start in 2011. A similar approach could be used to establish a science base for alternative fuels that can lead to emissions design models and a methodology for selecting—or limiting—future alternative fuels.

The objectives of this project are to: (1) establish the science base needed to develop accurate models for total unburned hydrocarbons (UHC), HAPs, non-volatile particulate emissions (PM), carbon monoxide (CO), and oxides of nitrogen (NOx) emissions from military gas turbine engines burning alternative fuels, and (2) establish a science-based methodology for selecting practical alternative fuels that minimize emissions.