Reaction Design, a leading developer of combustion simulation software, is adding the ability to accurately simulate soot particle size distributions, as well as total particulate-matter emissions to the FORTÉ computational fluid dynamics (CFD) package for realistic 3D modeling of fuel effects in internal combustion engines. (Earlier post.)
The new technology in FORTÉ was inspired by the accomplishments of the Model Fuels Consortium (MFC). Founded in 2005 by Reaction Design, the MFC is an industry-led project for the development of cleaner burning, higher-mileage vehicles. The MFC’s work focuses on creating software models and tools that enable engine designers to better determine the fuel effects on efficiency and emissions.
Soot formation occurs when fuels don’t fully combust, and recent studies show that soot particles smaller than 100 nanometers can be especially harmful to human health. In the past decade, engine exhaust regulations have been focused on limiting the total amount of soot (and NOx) emissions. Future particulate matter (PM) regulations, such as the European Union’s extended Euro 6 standard and the California Air Resources Board’s proposed Ambient Air Quality Standards require soot particle size and number limits in addition to total emissions mass limits. Such requirements are particularly challenging for engine designers.—Ellen Meeks, vice president of product development at Reaction Design
In Europe, Euro 5b/6 legislation introduced a particle number (PN) emission limit (6.0×1011/km) in addition to the mass-based limits for compression ignition engines. A particle number emission limit for gasoline vehicles—spurred by the adoption of gasoline direct injection engines—is to be defined by 1 September 2014.
Earlier this year, the Japanese Ministry of the Environment released the results of a 2010 study of micro particulate matter of less than 2.5 micrometers in diameter (PM2.5) which is known to cause respiratory issues that can range in severity from asthma to lung cancer. The study showed that most of the locations that were measured, particularly those near a main roadway, had average levels of PM2.5 that exceeded the current standard of less than 15 micrograms/cubic meter.
The MFC and Reaction Design have been working proactively to develop soot modeling approaches that can help reduce these harmful emissions, as we anticipate that more regulations will follow with increasingly strict limits on particle size and number. The ability to predict soot particle sizes and track their progress from formation through agglomeration and reduction in an engine is of significant benefit for engine developers, who will not only be able to better address air quality regulations, but also shave time from their design cycle.—Bernie Rosenthal, CEO of Reaction Design
When coupled with an accurate soot chemistry mechanism, such as the one developed by the MFC, the FORTÉ soot model provides engine designers with an accurate, physics-based approach to the prediction of soot size and mass emissions trends.