Comparison of Exhaust Emissions from Application of the Ramped Modal Cycle and Steady-State Nonroad Test 2005-01-1615
With input from industry, the United States Environmental Protection Agency (US EPA) has developed ramped modal versions of its steady-state certification duty cycles for land-based nonroad diesel engines. The Ramped Modal Cycle (RMC) calls for gathering gaseous and particulate emissions continuously over the cycle, while the steady-state test specifies that samples be taken for only a portion of the time at each mode. The RMC test was developed in part to capture discrete regeneration events associated with advanced catalyst systems like NOx adsorbers that are anticipated to meet future nonroad emission standards.1 To compare the emission levels between these two tests, a 5.9 liter medium-heavy-duty on-highway diesel engine rated for 260 hp @ 2500 rpm, was run at EPA's National Vehicle and Fuel Emissions Laboratory (NVFEL), derated to 180 hp @ 2500 rpm, to simulate the configuration of a typical nonroad engine. This engine was equipped with both PM and NOx control devices that are likely to be applied for meeting future long-term emission standards. The goal of this testing was to determine if the RMC emissions with a 2014-like engine and catalytic system correlated to the established 8-mode steady-state test.
Citation: Jackson, C., Sze, C., Schenk, C., Olson, B. et al., "Comparison of Exhaust Emissions from Application of the Ramped Modal Cycle and Steady-State Nonroad Test," SAE Technical Paper 2005-01-1615, 2005, https://doi.org/10.4271/2005-01-1615. Download Citation
Cleophas Jackson, Chien Sze, Charles Schenk, Brian Olson, Christopher Laroo
U.S. EPA - Office of Transportation and Air Quality