Ammonia is a kind of energy carrier of hydrogen, and its use as engine fuel has been studied. However, it requires overcoming shortcomings of low combustion speed. We focus that the laminar combustion velocity of gasoline mixture with an excess air ratio at 2.0 is the same as that of ammonia. The combustion of ammonia was simulated by using gasoline experiments under lean-burn conditions and the experimental engine with the sub-chamber and the glow plug. Through experiments, data such as the optimal ignition angle and NOx emissions during lean combustion are obtained. Based on the above experimental data, authors did the co-combustion experiment of gasoline/ammonia/air. Under the conditions of excess air ratio of 1.1, 1.2, 1.3, maximum ammonia content is 33%NH3, the engine could be operated with less than 10% variation in IMEP.
The use of laser irradiation for heating is characterized by localized heating and high power density heating, which make the method suitable for conducting thermal propagation tests for battery packs for electrified vehicles. This paper demonstrates a thermal propagation test for battery packs for PHEVs using laser irradiation. It describes one example of the practicality of using laser irradiation as an initiation method for thermal propagation tests for large battery packs for electrified vehicles. One of the advantages of laser irradiation, which is that thermal runaway occurs with minimal heating of adjacent cells, was confirmed to be maintained for the pack level test.
Initiation methods for thermal propagation tests are being discussed in the EVS-GTR. In this paper, laser irradiation was compared with nail penetration and heater heating using a prismatic Li-ion battery module from the viewpoint of heat energy transfer to adjacent cells. Such transfer with laser irradiation was 0.025% of that of heater heating and the adjacent cell’s temperature rise was less than 1°C by thermal runaway of the target cell. This result demonstrates that laser irradiation is a rational method in terms of replicating single cell thermal runaway only due to the cell’s own energy.
In this study, the influence of traffic environment on collision risk assessed by driving behavior indices of right turns at intersections were investigated. A driving simulator (DS) experiment and a risk simulation using the data obtained in the DS experiment were performed to investigate the influence. As a result of the investigation, the influence of the traffic environment on the relationship between the driving behavior indices and collision risk was clarified. Moreover, factors related to the influence, and a solution to consider the influence in risk assessment methods were discussed.
As concerns grow over the security of the Controller Area Network (CAN) bus used in modern cars, researchers are developing technologies to mitigate potential cyberattacks on it. Some of those technologies rely on CAN messages’ arrival timestamp (i.e., the point of time when a receiving node first observes the CAN frame) to measure slight differences between the clock references of Electronic Control Units (ECUs). Those technologies are promising, but several unknown factors still limit their efficiency and accuracy. Therefore, we investigated the properties of arrival timestamps of CAN messages and studied how network properties can impact them. First, we established a mathematical model for the case of two separate ECUs sending a message each. Then, we verified that model with a network simulator that can simulate an arbitrary number of ECUs sending arbitrary messages with different clock references. Finally, we verified those results on actual hardware and observed arrival timestamps for various scenarios. We concluded that the standard deviation of the arrival timestamp of periodic messages is a dynamic source of information about the physical network, rather than a static property of the sending ECU, as usually modeled. Those results can help researchers improve technologies that rely on CAN messages’ arrival timestamps.