Search Results (7)

Controlling vehicle speed is crucial for reducing exhaust emissions and ensuring the sustainable development of road transportation. Currently, speed limits on expressways are primarily set from a safety perspective, with limited research addressing speed limits from an environmental protection standpoint. In this study, based on real-world vehicle experiments and a vehicle flow exhaust emission model, we investigated the exhaust emission characteristics of light passenger vehicles (categorized as M1) and freight vehicles (categorized as N, including N1-minivans, N2-light heavy-duty vehicles, N3-medium heavy-duty vehicles, and N4-large heavy-duty vehicles) both individually and in traffic flows at varying speeds. We take carbon monoxide (CO), nitrogen oxides (NOx), particular matter (PM), and hydrocarbons (HCs) as representative emission components. The emission rate ranking of typical exhaust factors differs between M1-light passenger vehicles and N-freight vehicles. For M1-light passenger vehicles, the order is CO > HC > NOx > PM2.5, while for N-freight vehicles, it is NOx > CO > PM2.5 > HC. Conversely, for freight vehicles, higher speeds correlate with increased exhaust emissions in general, although carbon emissions specifically decrease as the speed increases. The results indicate the following speed limits conducive to sustainable road transportation development and low exhaust and carbon emissions: 90–110 km/h for light passenger vehicles and 80–100 km/h for freight vehicles. Full article

To validate active human body models for investigating occupant safety in autonomous cars, it is crucial to comprehend the responses of vehicle occupants during evasive maneuvers. This study sought to quantify the behavior of midsize male and small female passenger seat occupants in both upright and reclined postures during three types of vehicle maneuvers. Volunteer tests were conducted using a minivan, where vehicle kinematics were measured with a DGPS sensor and occupant kinematics were captured with a stereo-vision motion capture system. Seatbelt loads, belt pull-out, and footrest reaction forces were also documented. The interior of the vehicle was 3D-scanned for modeling purposes. Results indicated that seatback angles significantly affected occupant kinematics, with small female volunteers displaying reduced head and torso movements, except during emergency braking with a upright posture seatback. Lane-change maneuvers revealed that maximum lateral head excursions varied depending on the maneuver’s direction. The study concluded that seatback angles were crucial in determining the extent of occupant movement, with notable variations in head and torso excursions observed. The collected data assist in understanding occupant behavior during evasive maneuvers and contribute to the validation of human body models, offering essential insights for enhancing safety systems in autonomous vehicles. Full article

Air pollution, particularly from particulate matter (PM_2.5) and black carbon (eBC), has been implicated in airway pathologies. This study aims to assess the relationship between exposure to these pollutants and respiratory function in various populations, including healthy individuals, while seeking an accurate assessment method. A cross-sectional study was conducted in Bogotá, evaluating respiratory function in the users of bicycles, minivans, and buses through spirometry and impulse oscillometry. Measurements were taken along two main avenues, assessing the PM_2.5 and eBC concentrations. The results reveal higher pollutant levels on AVE KR 9, correlating with changes in oscillometry values post-travel. Cyclists exhibited differing pre- and post-travel values compared to bus and minivan users, suggesting aerobic exercise mitigates pollutant impacts. However, no statistically significant spirometry or impulse oscillometry variations were observed among routes or modes. Public transport and minivan users showed greater PM_2.5 and eBC exposure, yet no significant changes associated with environmental contaminants were found in respiratory function values. These findings underscore the importance of further research on pollutant effects and respiratory health in urban environments, particularly concerning different transport modes. Full article

With the introduction of “carbon neutrality”, promoting carbon peaking and carbon neutrality has become contingent upon the vigorous development of pure electric vehicles. The development of electric minivans is receiving substantial backing from the government as China’s logistics vehicle market undergoes a transformation. The drivers of electric minivans in China’s Shanxi Province are the objects of this research, whose purpose was to establish a service model based on the four elements of service design and grounded theory to clarify the key factors of user guarantee for electric minivans. We conducted a pilot study using questionnaires, user patterns, user interviews, and a user journey map to determine the user needs for electric minivan user service guarantees. NVivo was used to analyze and code the user interview data qualitatively. The research findings can serve as a resource for entrepreneurs, service providers, managers, and designers of electric minivans. Full article

To reduce aerodynamic drag of a minivan, non-smooth surfaces are applied to the minivan’s roof panel design. A steady computational fluid dynamics (CFD) method is used to investigate the aerodynamic drag characteristics. The accuracy of the numerical method is validated by wind tunnel test. The drag reduction effects of rectangle, rhombus and arithmetic progression arrangement for circular concaves are investigated numerically, and then the aerodynamic drag coefficient of the rectangle arrangement with a better drag reduction effect is chosen as the optimization objective. Three parameters, that is, the diameter D of the circular concave, the width W and the longitudinal distance L among the circular concaves, are selected as design variables. A 20-level design of an experimental study using a Latin Hypercube scheme is conducted. The responses of 20 groups of sample points are obtained by CFD simulation, based on which a Kriging model is chosen to create the surrogate-model. The multi-island genetic algorithm is employed to find the optimum solution. The result shows that maximum drag reduction effects up to 7.71% can be achieved with a rectangle circular concaves arrangement. The reduction mechanism of the roof with the circular concaves was discussed. The circular concaves decrease friction resistance of the roof and change the flow characteristics of the recirculation area in the wake of the minivan. The roof with the circular concaves reduces the differential pressure drag of the front and rear of the minivan. Full article

In this work, a structured design method, the Stylistic Design Engineering (SDE), is applied for the construction of a new minivan car, in particular a new city car, which we will call FIAT 600 Omega. The SDE, or Stylistic Design Engineering, is a structured engineering method for carrying out automotive design projects. The SDE method consists of six different phases: (1) Analysis of stylistic trends; (2) Sketches; (3) 2D Computer Aided Design (CAD) drawings; (4) 3D CAD models; (5) Rendering; (6) Solid stylistic model (also called style maquette). This project deals with the external redesign of the Fiat 600 multiple, a small minivan which was very successful in the 1950s and 1960s. SDE is a methodology consisting of various technologies and design methodologies that will be further explained in detail, such as the Pininfarina method, the Quality Function Deployment (QFD) method, Benchmarking (BM), and Top Flop Analysis (TPA). The work was organized according to the different phases. Initially, the Fiat style was studied, in particular the style of the FIAT 600 MULTI PURPOUSE VEHICLE (MPV). This step is essential to better understand the characteristics of the brand and also the main characteristics carried out over the decades. Then we moved on to the freehand sketching phase, based on what we learned in the previous phase of the study. When a satisfactory shape was found for the new car, by analyzing and discarding the different proposals of the various types of style, we proceeded to the evaluation of the proportions and dimensions through two-dimensional drawings and finally we obtained the three-dimensional shape of the new car thanks to 3D CAD software and rendering software. Many advantages in the industrial world SDE takes together with its development. In fact, until the early 2000s, car design and styling was considered quite a craft activity, not a technical or scientific one, mostly based on the great capability of famous car designers and masters, just like Giugiaro, Zagato, Bertone, Pininfarina, Stephenson, Bangle, etc. Then, thanks to the industrial activity of Eng. Lorenzo Ramacciotti, former CEO of Pininfarina Spa and Mechanical Engineer, and also thanks to the academic studies developed at ALMA MATER STUDIORUM University of Bologna, SDE became the object of attention, because it is able to systematize the car design process and reduce costs. With SDE, a good design research or an industrial product development team can complete a car design project, also without the presence of a mentor. Car Design Process finally becomes with SDE a scientific method; Car Design becomes with SDE an industrial method. Industrial needs are nice products made in a short time; SDE is structured to attend these issues. Industrial challenges follow innovation, in shape and functionality; SDE is able to recognize innovation. Industrial benefits can be reached with SDE, ensuring beautiful aesthetic projects are realized systematically and with low costs. Full article

Objectives: We report on a patient with whiplash injury who had central pain, due to injury of the spinothalamic tract (STT), but who was misdiagnosed as complex regional pain syndrome (CRPS). Case description: While a minivan in which a 43-year-old female was seated in the passenger seat was stopped for a signal, a truck collided with the minivan from behind, and the minivan then repeatedly collided with trucks in front and behind the minivan. Her head repeatedly struck the minivan seat resulting in whiplash injuries. After onset, she felt pain in both legs with mild motor weakness in all four extremities and memory impairment. Eight years after onset, she was diagnosed at a university hospital as CRPS type 1 with the clinical features of hyperalgesia and mild edema and motor weakness of both legs. She visited another university hospital nine years after onset and complained of pain in the right arm and both legs, constant tingling and burning pain along with allodynia and hyperalgesia. She also showed mild weakness in the four extremities, mild edema of both legs, and memory impairment. On diffusion tensor tractography (DTT), the left spinothalamic tract (STT) showed marked narrowing, and the right STT revealed mild narrowing and partial tearing. In addition, partial tears were observed in both corticospinal tracts and the right corticoreticulospinal tract. Discontinuations were observed in the left corticoreticulospinal tract and the left fornical crus. Conclusion: Injury of the STT was demonstrated on DTT in a patient with central pain following whiplash injury. Previously, the patient was misdiagnosed as CRPS. Full article