An ML-Enhanced Laser-Based Methane Slip Sensor Using Wavelength Modulation Spectroscopy.

Natural gas (NG) is a promising alternative to diesel for sustainable transport, potentially reducing GHG and air quality emissions significantly. However, the GHG benefits hinge on managing methane slip, the unburned methane in the exhaust of NG engines, which carries a significant global warming potential. The CH slip from NG engines is highly dependent on engine type and operation, and effective greenhouse gas emission mitigation requires that the actual operation of real-world engines is monitored.

Optical characterization of stratified-premixed natural gas direct-injection combustion regimes.

Gaseous fuels for heavy-duty internal combustion engines provide inherent advantages for reducing CO, particulate matter (PM), and NO emissions. Pilot-ignited direct-injected NG (PIDING) combustion uses a small pilot injection of diesel to ignite a late-cycle main direct injection of NG, resulting in significant reduction of unburned CH emissions relative to port-injected NG. Previous works have identified NG premixing as a critical parameter establishing indicated efficiency and emissions performance.

Heat release rate and emissions regimes of stratified pilot-ignited direct-injection natural gas combustion.

Natural gas (NG) is an attractive fuel for heavy-duty internal combustion engines because of its potential for reduced CO, particulate, and NO emissions and lower cost of ownership. Pilot-ignited direct-injected NG (PIDING) combustion uses a small pilot injection of diesel to ignite a main direct injection of NG. Recent studies have demonstrated that increased NG premixing is a viable strategy to increase PIDING indicated efficiency and further reduce particulate and CO emissions while maintaining low CH emissions.