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Planning for charging in transport missions is vital when commercial long-haul vehicles are to be electrified. In this planning, accurate range prediction is essential so the trucks reach their destinations as planned. The rolling resistance significantly influences truck energy consumption, often considered a simple constant or a function of vehicle speed only. This is, however, a gross simplification, especially as the tire temperature has a significant impact. At 80 km/h, a cold tire can have three times higher rolling resistance than a warm tire. A temperature-dependent rolling resistance model is proposed. The model is based on thermal networks for the temperature at four places around the tire. The model is tuned and validated using rolling resistance, tire shoulder, and tire apex temperature measurements with a truck in a climate wind tunnel with ambient temperatures ranging from -30 to 25 °C at an 80 km/h constant speed.

This paper investigates the tire-road interaction for tires equipped with two different solid rubber material definitions within a Finite Element Analysis virtual environment, ESI PAMCRASH. A Mixed Service Drive truck tire sized 315/80R22.5 is designed with two different solid rubber material definitions: a legacy hyperelastic solid Mooney-Rivlin material definition and an Ogden hyperelastic solid material definition. The popular Mooney-Rivlin is a material definition for solid rubber simulation that is not built with element elimination and is not easily applicable to thermal applications. The Ogden hyperelastic material definition for rubber simulations allows for element destruction. Therefore, it is of interest and more suited for designing a tire model with wear and thermal capabilities.

Reconstruction of inline crashes between vehicles with a low closing speed, so-called “low speed” crashes, continues to be a class of vehicle collisions that reconstructionists require specific methods to handle. In general, these collisions tend to be difficult to reconstruct due primarily to the lack of, or limited amount of, physical evidence available after the crash. Traditional reconstruction methods such as impulse-momentum (non-residual damage based) and CRASH3 (residual damage based) both are formulated without considering tire forces of the vehicles. These forces can be important in this class of collisions. Additionally, the CRASH3 method depends on the use of stiffness coefficients for the vehicles obtained from high-speed crash tests. The question of the applicability of these (high-speed) stiffness coefficients to collisions producing significantly less deformation than experimental crashes on which they are generated, raises questions of the applicability.

Truck platooning is an emerging technology that exploits the drag reduction experienced by bluff bodies moving together in close longitudinal proximity. The drag-reduction phenomenon is produced via two mechanisms: wake-effect drag reduction from leading vehicles, whereby a following vehicle operates in a region of lower apparent wind speed, thus reducing its drag; and base-drag reduction from following vehicles, whereby the high-pressure field forward of a closely-following vehicle will increase the base pressure of a leading vehicle, thus reducing its drag. This paper presents a physics-guided empirical model for calculating the drag-reduction benefits from truck platooning. The model provides a general framework from which the drag reduction of any vehicle in a heterogeneous truck platoon can be calculated, based on its isolated-vehicle drag-coefficient performance and limited geometric considerations.

Abstract Since the steady-state computational fluid dynamics (CFD) Reynolds-averaged Navier–Stokes (RANS) turbulence models offer low-cost and sensible accuracy, they are frequently utilized for bluff bodies’ external aerodynamics investigations (e.g., upwind, crosswind, and shape optimization). However, no firm certainty is made regarding the best model in terms of accuracy and cost. Based on cost and accuracy aspects, four RANS turbulence models were studied, which are Spalart–Allmaras, realizable k-ε, RNG k-ε, and SST k-ω. Ahmed body with a 25° slant angle benchmark case was introduced for this investigation. Two grids were generated to satisfy the near-wall treatment of each turbulence model. All grid settings were proposed and discussed in detail. Fluid-structure analysis was performed on five different planes.

The Environmental Protection Agency (EPA), in partnership with Research Triangle Institute (RTI International) and Auto Research Center (ARC-Indy), have created digital geometries of commercially available heavy-duty tractor-trailers. The goal of this effort was to improve the agency’s understanding of aerodynamic modeling of modern trucks and to provide opportunities for more consistent engagement on computational fluid dynamics (CFD) analyses. Sleeper and day cab tractors with aerodynamic features and a 53-foot box trailer with aerodynamic technology options were scanned to create high-resolution geometries. The scanning process consisted of a combination of physical scanning with a handheld device, along with digital post-processing. The completed truck geometries are compatible with most commercial CFD software and are publicly available for modeling and analyses.

Brazil is significant grain (soy, corn, beans and rice) producer in the planet and the road transportation is needed even when rail and maritime mode is used. There are opportunities to improve the grain road transportation efficiency. This paper presents one opportunity which is the aerodynamic drag reduction and therefore the fuel and energy consumption reduction on grain road transportation. This paper will discuss some alternatives to reduce aerodynamic drag on such application considering Brazilian market regulation which has a low limit for front axle load (lower than European regulation for instance) and limit the total composition length. As an example of some alternatives to reduce drag there is the frontal area reduction and trailer to cab gap reduction. Some of those alternatives were implemented on a concept truck briefly presented on this paper, which was tested on a real application, this paper will illustrate some of those alternatives implemented.

Tire rolling resistance and temperature are the main parameters for the design and driving of the heavy-duty tires due to their effects on fuel economy and safety. In this paper, the influence of many factors on the tire rollingresistance and temperature is studied, including speed, inflation pressure and normal load; the relationship between rolling resistance properties and temperature of heavy tires is studied based on several experiments to explore the physical mechanism and characteristics of tire rolling resistance for heavy-duty vehicles. The effects of the driving time and temperature of the tire on the rolling resistance are performed on tire’s experimental platform, in which the empirical models involved in the driving time and temperature of the tire for the rolling resistance are established using the least square method for fitting the experimental data.

Considerable effort is currently being focused on emerging vehicle automation technologies. Engineers are making great strides in improving safety and reliability, but they are also exploring how these new technologies can enhance energy efficiency. This study focuses on the changes in aerodynamic drag associated with coordinated driving scenarios, also known as “platooning.” To draw sound conclusions in simulation or experimental studies where vehicle speed and gaps are controlled and coordinated, it is necessary to have a robust quantitative understanding of the road load changes associated with each vehicle in the platoon. Many variables affect the drag of each vehicle, such as each gap length, vehicle type/size, vehicle order and number of vehicles in the platoon. The effect is generally understood, but there are limited supporting data in the literature from actual test vehicles driving in formation.

Aerodynamic interaction between vehicles on a roadway can modify the fuel use and greenhouse gas emissions of the vehicle relative to their performance under isolated, uniform-wind conditions. A comprehensive wind-tunnel study was undertaken to examine changes to the aerodynamic drag experienced by vehicles in close proximity, in adjacent lanes. Wind-load measurements were conducted for two general configurations: 15%-scale testing with light-duty-vehicle (LDV) models, and 6.7%-scale testing with a heavy-duty vehicle (HDV) model. For the LDV study, a DrivAer model was tested with a proximate AeroSUV model or an Ahmed model at lateral distances representing 75%, 100%, and 125% of a typical highway lane spacing, and for longitudinal distances up to 2 vehicle lengths forward and back. Commensurate measurements were conducted for the AeroSUV model with the proximate DrivAer or Ahmed model.

There have been many studies regarding the stability of vehicles following a sudden air loss event in a tire. Previous works have included literature reviews, full-scale vehicle testing, and computer modeling analyses. Some works have validated physics-based computer vehicle simulation models for passenger vehicles and other works have validated models for heavy commercial vehicles. This work describes a study wherein a validated vehicle dynamics computer model has been applied to extrapolate results to higher event speeds that are consistent with travel speeds on contemporary North American highways. This work applies previously validated vehicle dynamics models to study the stability of a five-axle commercial tractor-semitrailer vehicle following a sudden air loss event for a steer axle tire. Further, the work endeavors to understand the analytical tire model for tires that experience a sudden air loss.

Different tire models are applied in agricultural mobility, but the impacts on the ground are not completely known. Some models of industrial tires, with applications in construction machines, could meet the agricultural demand since there is a shortage offer exclusive models for agriculture. The aim of this research was to analyze in a Fixed Tire Testing Unit (FTTU), under controlled conditions, the performance of two tire types, the first for agricultural construction and the second for industrial construction on two different agricultural soils (two surfaces). The characteristics of the tires evaluated were: 620/75R26 (agricultural tire) and 23.5-25 (industrial tire). The soil used to simulate the agricultural surface were: Red Yellow Latosol and the Distroferric Red Nitosol, chosen because they are representative of agricultural areas in Brazil.

In recent years, there has been an overall reduction in greenhouse emissions in the European Union (EU); however, that is not the case for the transport industry where road transports are responsible for more than 70% of all the transports emissions. Transport by trucks and busses is responsible for a fourth of these greenhouse emissions, and a significant contributor to the energy consumption of these vehicles is the aerodynamic drag. A particular branch of truck transport is the transport of timber by the use of timber trucks. A significant difference to ordinary trucks is that the load of the timber truck affects the shape and hence its aerodynamic behavior. In Europe, these timber trucks travel at speeds of up to 80 km/h. At this speed, the aerodynamic drag accounts for around 20–30% per ton-km of the fuel consumption for these vehicles. In this paper computational fluid dynamics (CFD) is used to investigate and improve the aerodynamics of a loaded timber truck.

Abstract The future of heavy trucking will require greater aerodynamic improvements and will involve active and automated systems that tailor varied parameters to optimize energy efficiency over a broad operational range. Continuous advancement of accuracy and precision is needed to realize these ever-smaller aerodynamic gains and to generate more detailed aerodynamic characterizations to feed these system-wide optimizations. To accomplish this, a comprehensive aerodynamic development approach is needed and should include computational fluid dynamics, operational testing, and wind tunnel testing. In 2016, a high-fidelity 1/3 scale wind tunnel model of a tractor-trailer heavy truck was developed for Reynolds equivalent wind tunnel testing with full coverage rolling road ground simulation. The model and support system were designed and built for use in the Windshear rolling road wind tunnel.

Abstract Governmental regulations and customer demand for more energy-efficient vehicles are driving the development of new solutions in the automotive sector. One way of improving energy efficiency is by reducing the aerodynamic drag. A possible solution to achieve this is the concept of vehicles driving in close proximity, which is now becoming feasible considering the advances in vehicle automation and communication. This study focuses on the behavior of aerodynamic forces and flow effects in a two-truck platoon when more realistic road conditions, such as lateral offset and yaw, are present. The study is primarily numerical, but the results are validated against an experimental campaign conducted earlier by the authors. The main findings are that the drag of the leading truck is mostly governed by the base pressure of its trailer and that the truck sees only minor changes when a lateral offset is added, except at very short intervehicle distances.

In modern conditions, the rising cost of fuel and the adoption of more stringent environmental standards in developed countries require a reduction in fuel consumption by vehicles. The profitability of the trucking industry depends on the fuel economy of trucks, which, in turn, is determined by many factors, including their aerodynamic characteristics. The article substantiates new ways of reducing the aerodynamic drag of road trains based on a study conducted by the authors. Numerical simulation of the road train aerodynamics allows us to determine the distribution of velocity, pressure, and air turbulence zone around it. The effectiveness of known and proposed technical solutions to reduce the aerodynamic drag of trains with the use of spoilers of various designs has been evaluated and implemented. An effective way to reduce the aerodynamic resistance of road trains is proposed.

This article mainly studies the support interference effect elimination and test method of the scale model of a heavy truck in a wind tunnel. According to the formation mechanism, the support interference effect can be divided into two parts: aerodynamic interference effect (the aerodynamic drag of the support device) and flow field interference effect (the aerodynamic change of the tested model caused by the flow field of the support device); the former is mainly the horizontal rod and the vertical rod of the support device. However, the latter is related to the change of the body flow field, which needs to be quantitatively evaluated by means of computational fluid dynamics (CFD) simulation.

This SAE Standard applies to all combinations of pneumatic tires, wheels, or runflat devices (only as defined in SAE J2013) for military tactical wheeled vehicles only as defined in SAE J2013. This applies to original equipment and new replacement tires, retread tires, wheels, or runflat devices. This document describes tests and test methodology, which will be used to evaluate and measure tire/wheel/runflat system and changes in vehicle performance. All of the tests included in this document are not required for each tire/wheel/runflat assembly. The Government Tire Engineering Office and Program Office for the vehicle system have the responsibility for the selection of a specific test(s) to be used. The selected test(s) should be limited to that required to evaluate the tire/wheel/runflat system and changes in vehicle performance.

This SAE Standard provides test procedures, requirements, and guidelines for motorcycle turn signal lamps. It does not apply to mopeds.

Abstract A non-pneumatic tire (NPT) has a lot of applications and is a viable option for the future, as they do not possess the problem of blowouts and air pressure maintenance. In these NPTs, the air-filled part is replaced by a flexible structure capable of withstanding the weight of the vehicle and delivering optimum performance. In the present study, endeavors have been made to analyze the rolling performance of NPTs by considering a light commercial vehicle as an application. The NPTs with three different configurations are studied by considering three hyperelastic material models for the hexagonal spoke structure and shear band under various loading conditions. Initially, static analysis for the models is conducted in two dimension (2D) and three dimension (3D) to validate the results, and these models were further extended to rolling analysis. The rolling resistance and slip ratios are obtained and compared in both 2D and 3D analyses.