Exploring pathways to negate safety concerns and improve public acceptance of alternative fuelled electric vehicles

Restricted emission regulations force the transportation sector to seek a better vehicle fuel solution, and the uptake of Electric Vehicle is to be encouraged because it has no exhaust emission. Previous literature had shown that range freedom and cost were the main barriers and safety aspects were often considered as technological issues. Recent research indicates that early adopters of innovative EVs do have concerns about safety issues although it was not on top of the list. However, research into the public perception of alternative fuelled EVs in terms of safety has been limited to date. In this paper, a quantitative study is undertaken to investigate the public safety concern of three types of vehicle powertrain: the internal combustion engine, the hybrid electric and the solely electric vehicle. The survey consisted of two identical sets of questionnaires (one was in English, and another in Chinese) to collect data from people with different cultural background. It was expected that this would provide a reasonable number of responses to reflect the public. This study indicates that the main safety concerns are associated with the level of vehicle knowledge and the power supply components despite the powertrain type. The high awareness of mechanical failure is only evident in the conventional fuel powertrain and gradually reduced when moving towards solely electric powertrain to compensate for the rise of electrical failure awareness. It also indicates that the awareness of the specifics of hydrogen fuel cell vehicles is not widespread amongst the public as almost all the participants considered that the electric vehicle is powered by batteries only. As a result, this paper suggests that there is a need to educate the drivers with the desired knowledge while simply driving the vehicle could potentially be an effective way to improve public acceptance of any alternative fuel vehicl

The influence of driver's psychological states on the safety perception of hydrogen electric vehicles

The environmental and sustainable problems caused by automotive exhaust emission have received more attention than ever. Innovative vehicle technologies, such as hydrogen fuel cell and electric vehicles, have been developed a long time ago to cope with the problem. Public acceptance of these electric vehicle technologies is critical to their successful replacement of the internal combustion engine vehicles and thus reduce the emissions. Previous researches had shown that the main barriers were the lack of support infrastructures, high vehicle purchase cost and vehicle reliability with respect to safety. However, studies into the public safety perception of hydrogen-fuelled vehicles have still been limited to date. In this paper, a quantitative survey was developed to investigate the public safety concerns of three types of vehicle powertrain: the internal combustion engine, the hybrid electric and the solely electric vehicle. The study indicates the root cause of the low safety perception at present. The survey results also indicate that that driving freedom is nowadays not just a problem of infrastructure only but is gradually becoming a psychological issue in terms of increased driver’s mental stress, and thus, the overall driving safety is affected. Furthermore, this paper states the existence of an evaluation chain to determine the driver’s safety perception. In the end, this paper proposed a comprehensive framework of the negation of driver’s safety concerns regarding the hydrogen-fuelled electric vehicle, based on the results from the survey and a review of psychological effects. This framework intends to explain the perceived safety perception from a wider angle with some in-depth

Simulations of engine knock flow field and wave-induced fatigue of a downsized gasoline engine

A mathematical correlation is developed, based on the thermodynamic model of a downsized gasoline engine, to establish the numerical relationship among the thermodynamic parameters of the combustion chamber. In the developed numerical model, the in-cylinder pressure curves of various operation condition are simulated by varying the air-fuel ratio in the cylinder, and the associated knock characteristics are recorded. The accuracy of the numerical simulation results is verified against the knock excitation experiment. Then, based on the Rover K16 gasoline engine, a simulation model is developed to simulate the engine knock in the combustion chamber and observe the force acting on the top surface of the piston. The results show that the forces act on the piston top surface are varying at various locations at the same time, and the largest forces occur at the edge of the piston and followed by the piston centre. Then, by comparing the thermo-mechanical coupling strength of the piston under different operating conditions, the results show that the occurrence of the knocking does not exceed the piston's strength limit. However, the stress and deformation value of the piston is increased significantly, and the failure point of the piston position is changed. Finally, based on the calibrated strength results, the piston durability is predicted for various engine knock conditions. The results show that the initial damage of piston in the process of detonation at the surface of the piston pin hole and the joint of the piston cavity. The gasoline engine finally has a predicted mileage of 253,440 km continuously which meet the prescribed mileage of 220,000 km

Simulation study of particle–fluid two-phase coupling flow field and its influencing factors of crystallization process

Obtaining the morphology of two-phase flow field accurately through experiments is very challenging, due to the complexity and the drainage area diversity of particle–fluid two-phase flow. Depending on the particle concentration, size, flow velocity, and so on, the two-phase flow tends to be in a more complex form, known as coupled flow status. Crystallisation process within a crystalliser is a typical engineering application of particle–fluid two-phase flow, and hence, the flow field within a potassium salt crystallizer is implemented to simulate the crystal suspension and to mix flow state during a continuous crystallisation process. Because the two-fluid model treats the particle phase and fluid phase as two distinct continuous media, this simulation model takes the effect of virtual mass force into considerations. The enhanced two-fluid model is then applied to investigate the influencing factors of the coupled flow field between the potassium salt particles and the fluid in the crystalliser under various operating conditions. The results indicated that the stirring speed, the concentration of the feed particles, and the particle size affected the distribution of coupled flow field at different levels and, thus, affected the crystallisation phenomena of a potassium salt. Among those factors, the stirring speed appears to have the most obvious effect on the flow field, as it affects the velocity of the two-phase flow. In the conditions listed in this paper, the minimum stirring speed is roughly 50 rpm to form a stable and circular flow field in the crystallizer, and the maximum particle size is controlled at around 12 mm and the feed particle concentration of roughly 32% to ensure cyclic crystallization. The research method used in this article provides a baseline for the study of the coupled flow field of particle–fluid two-phase flow and its influencing factors. This research also states theoretical guidance for the optimisation of operating conditions in the production and application of potassium salt crystallizer

How safe is your hydrogen-powered car? - some safety and human factors issues

Scientists have shown that the causes of climate change are mainly due to carbon dioxide (CO2) and other emission gases generated by burning fossil fuels. Amongst all sectors, tailpipe pollution is always a keyword that cannot be avoided in any climate-related conversations. It has been considered a significant contributor to global air pollution and eventually global warming. Industrial professionals, researchers, and engineers advocate hydrogen as a potential fuel for delivering energy instead of fossil fuel due to its chemical nature. Nowadays, various models and sizes of Hydrogen Fuel Cell Vehicles (HFCVs) are running on the road.However, the safe retrofitting of fuel cells into areas with little prior experience with hydrogen, especially domestic environments, can raise many new issues. In transport applications, people are most likely to associate hydrogen fuel with the Hindenburg disaster (1937) and mistakenly attribute the explosion to hydrogen. This misunderstanding may steer public perception about hydrogen fuel and mislead the safety judgement. With the growing awareness of HFCVs among a broader audience, extending beyond the Subject Matter Experts (SMEs), their safety has become an ongoing debate to the general public. Therefore, this thesis aims to study the safety issues related to hydrogen fuel cell vehicles from a human factor perspective. The ultimate goal is to understand the potential impacts of HFCV usage on the future road transport system with regard to safety.The first study of this research is a quantitative study investigating the public safety concern of different vehicle powertrains. It revealed that the awareness of the specifics of hydrogen fuel cell vehicles is not widespread amongst the general public. It is difficult for people to comment on any specific aspect of HFCV safety concerns as they have not had such an experience. Hence, the outcomes of this study also suggested that the second study should provide participants with a certain level of HFCV driving experiences.The second study of this research assesses the changes in drivers’ perceptions of the HFCV and associated consequences before and after an HFCV test drive. The outcomes of this study revealed that experiencing vehicle performance differences and being able to know hydrogen-related knowledge are the two key factors that cause drivers’ behaviour changes. The impacts of different perception changes are discussed, and potential improvement strategies are also suggested.The third study of this research investigates the UK emergency responders’ perceptions of hydrogen fuel cell vehicles. This is because, when a Road Traffic Collision (RTC) occurs involving an HFCV, the public will rely on emergency personnel to handle the collision and ensure the safety and efficient rescue of the drivers, passengers, and other road users. However, emergency responders’ perceptions have never been explored and better understood. The results revealed that firefighters have different perceptions of the HFCVs than the general public. Further analysis indicates the differences between their perceptions of HFCV safety and engineers/general public perceptions. Recommendations to address these concerns are discussed as well as the political implications.Finally, all the findings from these studies are summarised, discussed, and concluded according to the scope of the thesis and research questions, including descriptions of the limitations and identifications of potential improvement pathways.</p

Emergency responders' perceptions of Hydrogen Fuel Cell Vehicle: A qualitative study on the U.K. fire and rescue services

Due to the fast growth of the Hydrogen Fuel Cell Vehicle (HFCV) market, the chances of these vehicles being involved in road crashes is also likely to increase. However, to date, studies into the Emergency Responders' perceptions of the HFCV have been limited. This paper investigates such perceptions of HFCVs through the interviews with firefighters. Through a pilot study results, initial findings suggest that firefighters are the ones who work next to the HFCV in post-crash scenarios, hence, they can provide more insightful information. As a result, 19 themes regarding their perceptions were discovered. The results show that the firefighters have different perceptions of the HFCV regarding the “economic cost”. Further analysis indicates the contradictions in their perceptions, and also shows they had more concerns about rescue-oriented safety rather than the fire-oriented safety. Finally, recommendations to address these concerns are discussed as well as the political implications of the results

Anti-penetration performance of high entropy alloy–ceramic gradient composites

A high-entropy alloy–ceramic gradient composite of TiC–TiB 2 /75vol% Al 0.3 CoCrFeNi was successfully prepared by combustion synthesis under an ultra-high gravity field, which is a low-cost method with high efficiency. The ceramic particles were gradient distributed in the Al 0.3 CoCrFeNi matrix, and the hardness of the composite material gradually decreased along the thickness direction. The anti-penetration performance of the gradient composites was simulated using the ANSYS/LS-DYNA explicit simulation program. The results demonstrate that the distribution of the ceramic particles strongly affected the mechanical properties and the anti-penetration performance of the composites. With the same total ceramic volume fraction, the gradient composites exhibit better anti-penetration performance than the corresponding ceramic–metal interlayer composites. The more uneven the ceramic distribution, the greater the elastic modulus and yield stress of the surface layer and, thus, the better the anti-penetration performance