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The partially stratified charge (PSC) injection ignition strategy aims to improve thermal efficiency and reduce emissions of lean-burn spark-ignited internal combustion engines by extending the lean limit of operation. The object of the current study is to characterize the pre-ignition formation of the fuel plume in the vicinity of the PSC spark plug, using a complementary experimental and numerical approach. Visualization of the PSC plume was conducted using Schlieren motion photography in a constant volume pressure chamber at various injection pressures and signal durations. Inlet conditions were determined with 1-D and 2-D numerical models derived from experimental conditions. Subsequently, the 3-D numerical study was carried out with FLUENT using the SST k-ω turbulence model. It was found that the simulation results were adequate in representing the experimental data in terms of injection angle and jet penetration.

This paper presents a comprehensive steady-state numerical study for an occupant-loaded vehicle seat with internal heating under severe winter conditions. A participant-based postural study showed that the nominal peak occupant seat pressure was 6kPa on the seat cushion, and 2.5kPa on the backrest. Uni-axial compression tests also indicated non-linear stress-strain behaviors in seating. Using an internally developed 3-D numerical model, it was found that the thermal resistance from contact and clothing was uniform (hc=144W·K−1·m−2) throughout the occupied regions. Their contribution to the overall thermal resistance was relatively minor, however, compared to that of skin (hoverall=27.2W·K−1·m−2). The thermal-mechanical simulations were conducted at heat input levels between 20W and 80W, using I-DEAS 10 and the TMG package as the simulation platform. Comparisons was also made between occupied seat with deflected and non-deflected mesh.