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In this study, a new method to calculate the spray collapse in multiple-hole gasoline injectors was developed. The theoretical calculation method was proposed by applying the extended spray momentum theory. In this theoretical calculation method, the deflection of the spray direction toward the injector axis was calculated serially based on the imbalance of the momentum of backward gas-flow surrounding sprays. The calculation and spray observation for validation against the calculation result were performed under conditions with and without flash boiling.

In case of electric vehicle (EV), as there are various thermal system configurations in each automotive manufacturer, suppliers should take a huge amount of time to select the best components for each OEM system. To solve this problem, a model-based development (MBD) method switching components easily and estimating their benefits efficiently is needed. In this study, the vehicle energy flow model was developed to select appropriate system configuration and components to balance cabin comfort and battery lifetime. To realize required accuracy and computing time, a 1D model, which has a motor, an air-cooling battery, a coolant circuit and heating ventilation and air-conditioning (HVAC) in a cabin, based on C-segment vehicle, was developed.

In a Diesel engine with a Diesel particulate filter (DPF) system, high-sulfur fuel causes white smoke containing odorous and harmful pollutants during DPF regeneration. This study investigates the conditions and mechanisms of sulfur-related white smoke generation. Engine and vehicle tests found that sulfur compounds emitted from the engine accumulated on the catalysts in the DPF system and were emitted as white smoke during DPF regeneration. The white smoke was observed when the catalyst temperature was more than 450°C, under conditions such as the early stage of DPF regeneration. Model gas tests were conducted to clarify the mechanism of the white smoke. It was found that SO2 emitted from the engine was oxidized to SO3 on the catalyst, which was then mainly absorbed on the oxidation catalyst support (Al2O3). Then, the absorbed SO3 was desorbed and converted into white smoke.