Combustion Visualization

Exploring combustion using advanced imaging techniques

GM Diesel Test Cell

To meet stringent EPA emissions standards while maintaining high fuel efficiency and power density, detailed information about combustion is needed. Utilizing endoscopes, advanced cameras and fiber-optic tools, detailed information about combustion can be acquired. Information such as soot formation, presence of intermediate combustion reaction species, in-cylinder mixing, fuel spray characterization, and combustion temperature are explored using advanced imaging techniques.

These projects provide detailed combustion information, using real-world engines and technologies, that give automobile and truck manufacturers the data they need to build environmentally friendly vehicles. All manufacturers are exploring non-traditional combustion regimes that produce low temperature combustion (LTC), allowing for very low NOx emissions, which significantly eases the burden on exhaust aftertreatment systems. With the tools described below, Argonne can test the influence of advanced technologies on combustion and emissions and still utilize real-world, production hardware.

In the photo, the GM diesel test cell is shown with vehicle exhaust aftertreatment (DPF and DOC) along with other advanced technology hardware - such as a variable geometry turbocharger, cooled EGR and a common-rail fuel injection system.

Argonne's combusion research projects

Hydrogen Combustion OH Chemiluminescence

Natural Combustion Luminosity. Using an endoscope, this technique provides a 2-Dimensional look at several combustion characteristics; such as soot radiation data for soot volume fraction and soot temperature, or chemical information for combustion species emission in the visible wavelength band. In addition, information such as ignition location and timing, spray/air interactions are measured. The photo at right depicts a 2-D image of hydrogen combustion visualized by using OH* chemiluminescence inside a running engine. The image provides qualitative information about hydrogen combustion intensity, location and temperature.

Combustion Visualization

OH*/CH* Spectroscopy. Using fiber optics, very high resolution measurements of the radiation emission of excited chemical species in the combustion reaction zone. This allows for a combustion temperature estimation to be calculated as a highly resolved function of time, providing a temperature profile of the combustion event from beginning to end. The image at left shows diesel combustion from inside the engine combustion chamber using visible light soot radiation. The injector tip and injection sprays can be clearly seen, along with combustion. Images like this can be analyzed to calculate soot volume fraction and soot radiation temperature.

May 2008