The combustion processes of homogeneous charge compression ignition （HCCI） engines whose piston surfaces have been coated with catalyst （rhodium or platinum） were numerically investigated. A singlezone model and a...The combustion processes of homogeneous charge compression ignition （HCCI） engines whose piston surfaces have been coated with catalyst （rhodium or platinum） were numerically investigated. A singlezone model and a multi-zone model were developed. The effects of catalytic combustion on the ignition timing of the HCCI engine were analyzed through the single-zone model. The results showed that the ignition timing of the HCCI engine was advanced by the catalysis. The effects of catalytic combustion on HC, CO and NOx emissions of the HCCI engine were analyzed through the multi-zone model. The results showed that the emissions of HC and CO （using platinum （Pt） as catalyst） were decreased, while the emissions of NOx were elevated by catalytic combustion. Compared with catalyst Pt, the HC emissions were lower with catalyst rhodium （Rh） on the piston surface, but the emissions of NOx and CO were higher.展开更多
Bifurcation analysis of ignition and extinction of catalytic combustion in a short micro-channel is carded out with the laminar flow model incorporated as the flow model. The square of transverse Thiele modulus and th...Bifurcation analysis of ignition and extinction of catalytic combustion in a short micro-channel is carded out with the laminar flow model incorporated as the flow model. The square of transverse Thiele modulus and the residence time are used as bifurcation parameters. The influences of different parameters on ignition and extinction behavior are investigated. It is shown that all these parameters have great effects on the bifurcation behaviors of ignition and extinction in the short micro-channel. The effects of flow models on bifurcation behaviors of combustion are also analyzed. The results show that in comparison with the flat velocity profile model, for the case of the laminar flow model, the temperatures of ignition and extinction of combustion are higher and the unsteady multiple solution region is larger.展开更多
基金the National Key Basic Research Development Project of China (2001CB209201)
文摘The combustion processes of homogeneous charge compression ignition （HCCI） engines whose piston surfaces have been coated with catalyst （rhodium or platinum） were numerically investigated. A singlezone model and a multi-zone model were developed. The effects of catalytic combustion on the ignition timing of the HCCI engine were analyzed through the single-zone model. The results showed that the ignition timing of the HCCI engine was advanced by the catalysis. The effects of catalytic combustion on HC, CO and NOx emissions of the HCCI engine were analyzed through the multi-zone model. The results showed that the emissions of HC and CO （using platinum （Pt） as catalyst） were decreased, while the emissions of NOx were elevated by catalytic combustion. Compared with catalyst Pt, the HC emissions were lower with catalyst rhodium （Rh） on the piston surface, but the emissions of NOx and CO were higher.
基金the National Key Basic Research Project of China(No.2001CB209201)
文摘Bifurcation analysis of ignition and extinction of catalytic combustion in a short micro-channel is carded out with the laminar flow model incorporated as the flow model. The square of transverse Thiele modulus and the residence time are used as bifurcation parameters. The influences of different parameters on ignition and extinction behavior are investigated. It is shown that all these parameters have great effects on the bifurcation behaviors of ignition and extinction in the short micro-channel. The effects of flow models on bifurcation behaviors of combustion are also analyzed. The results show that in comparison with the flat velocity profile model, for the case of the laminar flow model, the temperatures of ignition and extinction of combustion are higher and the unsteady multiple solution region is larger.
