Experiments on Waste Heat Thermoelectric Generation for Passenger Vehicles

In order to utilize waste heat from passenger vehicles by a thermoelectric generator (TEG), a lab-scale TEG with a sufficient low-pressure drop was designed and tested. The waste heat from a 2.0 L petrol engine was simulated by using an air-circulation channel with an adjustable electric heater and a speed control motor. The TEG consisted of an integrated molding designed aluminum-finned heat collector, twenty thermoelectric modules, and a set of water-cooled heat sinks. Experiments were conducted in terms of power load feature, pressure drop, heat collection efficiency, thermoelectric efficiency and overall efficiency. It was found that the hot-end temperature was much lower (46.9%) than the flue gas temperature because the trade-off between fin area and pressure drop had to be considered. The obtained maximum electric power was 36.4 W, and the corresponding pressure drop was 36 Pa. The corresponding heat collection efficiency was 46.5%, and the thermoelectric efficiency was 2.88%, which agreed well with the theoretical prediction of 3.38%. As a result, an overall efficiency of 1.21% was reached. The present work firstly demonstrated a waste-heat-recovering TEG prototype with a balanced overall efficiency of over 1%, and a pressure drop of less than 50 Pa. On the other hand, the maximum electric power was difficult to fully extract. The charging power to a battery with a maximum power point tracking direct current–direct current converter was experimentally verified to work at a much higher conversion efficiency (15.3% higher) than regular converters.

The Effect of Afterbody Geometry on Passenger Vehicles in Platoon

It is well known that platoons of closely spaced passenger cars can reduce their aerodynamic drag yielding substantial savings in energy consumption and reduced emissions as a system. Most published research has focused on platoons of identical vehicles which can arguably be justified by some evidence that geometric variety has little to no effect on the overall flow characteristics in platoons of three vehicles or more. It is known that much of the aerodynamic benefit from platooning is gained by the leading two cars, so operating as vehicle pairs could potentially achieve similar environmental benefits whilst addressing many of the practical challenges associated with the safe operation of long platoons on public roads. However, it has been reported that unlike long platoons, the effect of geometry and arrangement is critical if the drag reduction of a pair is to be optimised. This paper describes a parametric study based on three geometric variants of the popular DrivAer model with different combinations and spacings. It is confirmed that vehicle geometry crucially affects the results with the best combinations matching those of long platoons and others creating a net drag increase.

Drag reduction mechanisms on a generic square-back vehicle using an optimised yaw-insensitive base cavity

Regulations on global greenhouse gas emission are driving the development of more energy-efficient passenger vehicles. One of the key factors influencing energy consumption is the aerodynamic drag where a large portion of the drag is associated with the base wake. Environmental conditions such as wind can increase the drag associated with the separated base flow. This paper investigates an optimised yaw-insensitive base cavity on a square-back vehicle in steady crosswind. The test object is a simplified model scale bluff body, the Windsor geometry, with wheels. The model is tested experimentally with a straight cavity and a tapered cavity. The taper angles have been optimised numerically to improve the robustness to side wind in relation to drag. Base pressures and tomographic Particle Image Velocimetry of the full wake were measured in the wind tunnel. The results indicate that a cavity decreases the crossflow within the wake, increasing base pressure, therefore lowering drag. The additional optimised cavity tapering further reduces crossflow and results in a smaller wake with less losses. The overall wake unsteadiness is reduced by the cavity by minimising mixing in the shear layers as well as dampening wake motion. However, the coherent wake motions, indicative of a balanced wake, are increased by the investigated cavities. Graphical abstract

The Energy Consumption of Passenger Vehicles in a Transformed Mobility System with Autonomous, Shared and Fit-For-Purpose Electric Vehicles in the Netherlands

Aims: This article explores the tank-to-wheel energy consumption of passenger transport at full adoption of fit-for-purpose shared and autonomous electric vehicles. Background: The energy consumption of passenger transport is increasing every year. Electrification of vehicles reduces their energy consumption significantly but is not the only disruptive trend in mobility. Shared fleets and autonomous driving are also expected to have large impacts and lead to fleets with one-person fit-for-purpose vehicles. The energy consumption of passenger transport in such scenarios is rarely discussed and we have not yet seen attempts to quantify it. Objective: The objective of this study is to quantify the tank-to-wheel energy consumption of passenger transport when the vehicle fleet is comprised of shared autonomous and electric fit-for-purpose vehicles and where cheap and accessible mobility leads to significantly increased mobility demand. Methodology: The approach consists of four steps. First, describing the key characteristics of a future mobility system with fit-for-purpose shared autonomous electric vehicles. Second, estimating the vehicle miles traveled in such a scenario. Third, estimating the energy use of the fit-for-purpose vehicles. And last, multiplying the mileages and energy consumptions of the vehicles and scaling the results with the population of the Netherlands. Results: Our findings show that the daily tank-to-wheel energy consumption from Dutch passenger transport in full adoption scenarios of shared autonomous electric vehicles ranges from 700 Wh to 2200 Wh per capita. This implies a reduction of 90% to 70% compared to the current situation. Conclusion: Full adoption of shared autonomous electric vehicles could increase the vehicle-miles-travelled and thus energy use of passenger transport by 30% to 150%. Electrification of vehicles reduces energy consumption by 75%. Autonomous driving has the potential of reducing the energy consumption by up to 40% and implementing one-person fit-for-purpose vehicles by another 50% to 60%. For our case study of the Netherlands, this means that the current 600 TJ/day that is consumed by passenger vehicles will be reduced to about 50 to 150 TJ/day at full adoption of SAEVs.

Barriers to and Opportunities for Light-Duty Vehicle Electrification in India: Insights From a Survey of Experts

According to the World Health Organization, India has the world’s worst air quality. Among other factors, vehicular pollution from the increasing stock of passenger vehicles has contributed to India’s deteriorating air quality. This increasing stock is also a factor in India becoming the third-highest oil-consuming and greenhouse gas (GHG)-emitting country worldwide.

Measures to reduce enviromental risk on transport in the regions

One of the producers of pollution in the natural environment and on natural and anthropogenic objects is transport, which emits harmful vapors when driving on highways. The spread of pollution occurs during the movement of transport along the air and water flow. The article investigates the level of environmental pollution from vehicles in the regions of Russia, reveals the total percentage of emissions from passenger vehicles. The analysis of emissions has been carried out based on data from the Federal Service for Supervision of Natural Resources Management (Rosprirodnadzor) using empirical and mathematical, statistical methods. A brief description of the method of calculation of evaporation from transport has been given. In the course of studies, various groups the total values of emissions for various transport groups in the regions have been identified, environmental zones have been determined. The dynamics of changes on transport over the past three years has been traced. The regions most affected by harmful emissions have been considered, measures to reduce environmental risk have been proposed. The necessity of a national project on ecology and air purification has been substantiated. Environmental problems in transport pose a great threat to the environment, it is impossible to reduce emissions immediately, but if you gradually apply measures to minimize pollution, you can improve the environmental situation in the regions.

Recycling Potential of Plastic Resources from End-of-Life Passenger Vehicles in China

A rapid increase in the number of end-of-life (EoL) passenger vehicles has led to a large amount of waste plastics in China. However, the scale and efficiency of recycling resources from EoL vehicles still restricts the sustainable and healthy development of the automotive industry. The current behavior of automotive/recycling industry entities, as well as the strategy of waste management policymakers, may depend on the potential of total recyclable resources. To reveal such recycling potential of various plastic materials in EoL passenger vehicles, we predicted total EoL passenger vehicles in China from 2021 to 2030 (used the Weibull distribution) considering passenger vehicle ownership (estimated by the Gompertz model), quantified the demand for new passenger vehicles (estimated using its non-linear relationship with income level and passenger vehicle ownership), and assessed the recyclable plastics by categories and by provinces. The results show that (i) the annual average recycled plastic resources from EoL vehicles would exceed 2400 thousand t in 2030, more than 2.5 times in 2021, showing a great recycling potential; (ii) the differences among the three scenarios are relatively small, indicating that no matter the saturation level of passenger vehicles in China would be high or low, a rapid increase of recyclable plastic resources can be expected from 2021 to 2030; (iii) at the provincial level, a considerable gap between the potential of recycling plastic from EoL passenger vehicles and the regional processing capacity. Given such great potential and regional differences, the recycling policies should be applied in stages and consider the development level and recovery pressure in each region.