• Energy Research

Abstract Automobiles are considered as a large-scale vibrational source what makes automotive is a target to harvest such a considerable kinetic energy otherwise being dissipated by traditional viscous shock absorbers. The power dissipation during the damping events can be partially regenerated based on linear or rotary electromagnetic energy-harvesting dampers. This paper analytically discusses the potential power content of a class-6 heavy-duty truck with respect to different driving circumstances. Considering variable speed schedules of heavy vehicles, 10 driving cycles are proposed in creating ISO based random road profiles with variable speed vectors including both aggressive and nonaggressive driving trips. Further, the laden and the unladen truck cases were considered in the analysis with respect to 6-DOFs truck suspension model. Additionally, the energy harvesting and truck comfort were investigated over the running conditions. Given the results, a potential power content of 71–434 W and 287–1733 are available for ISO road grades of C and D, respectively, for a fully-loaded truck. The results suggested that the higher power quantity is related to aggressive body-wheel relative movements in which such conditions are found in case of the aggressive driving events and the vehicles with greater mass such as the heavy trucks and off-road vehicles.

Abstract The energy-harvesting, which is traditionally dissipated during the damping of the passive telescopic damper of an off-road sport-utility vehicle (SUV), was experimentally analyzed and quantified in this study. Thereafter, the following real-road driving scenarios were proposed at 10–40 km/h: (a) off-road and (b) city-road driving. The study also includes measurements of the power dissipations in the compression and rebound phases because some energy harvesters only recover energy in one phase. Thus, the rear-right suspension was equipped with acceleration sensors. The shock displacement was also recorded for the complete analyses and comparison of the dynamics and energy-harvesting during the jounce and rebound vibrations. The results indicated that the damper dissipated average powers of 30–334 and 3–25 W at 10–40 km/h on the off-road and city-road fields, respectively. The damper dissipated six times more energy in the rebound phase than in the compression phase. This harvested power could be employed to drive low-power electronics.

Abstract Automobiles are dissipating a considerable amount of vibration energy that is worth of being harvested where it can be exploited in different applications. For a full vehicle suspension assembly, the conflict between the potentially harvested energy and vehicle dynamics represented by ride quality and road safety and handling was comprehensively illustrated for different input modes. The discrepancy between the bounce input mode and the roll input mode was also sufficiently clarified based on an extensive parametric analysis covering the design parameters and the operational parameters as well. Comprehensive simulations were then conducted to estimate the amount of wasted energy in vehicle suspension system for different types of cars (passenger, bus, truck, and off-road vehicle), besides the potential harvested power was quantified for different standard driving cycles (NEDC, WLTP, HWFET, and FTP). Based on that, a 7-DOF full car suspension model was implemented in Matlab/Simulink environment and induced by different levels of road irregularities. The findings of this paper showed that the vibration intensity levels changed clearly in the complex input mode that reflects a realistic view of the real vehicle dynamics on the roads compared to the ideal results from the bounce input mode. Our results also indicate that a potential power up to 420 W can be collected considering standard driving patterns and roll mode input. The analysis indicates that the overloaded vehicles are suitable for the energy harvesting system based on the harvestable energy per unit cost.

This paper investigates the effects of tire characteristics on vehicular rollover and lateral stability. Two tire types with different adhesion coefficients were selected to evaluate the relation between vehicular rollover propensity and lateral stability. Simulations were used to calculate the critical rollover factor and to analyze the effects of vehicular parameters on handling, including the center of gravity, payload condition, and vehicle speed, with the two proposed types of tires. To replicate an actual vehicular response, particularly during extreme driving operations, a two-degrees of freedom (DOF) planar two-track model with nonlinear Pacejka’s Magic Tire Formula was applied. Subsequently, a 7-DOF vehicle vibration and roll model was developed to consider the effects of suspension and road excitation. The tire, steering, and vehicle vibration models were implemented in MATLAB/Simulink by subjecting them to the Fishhook maneuver steering input defined by the National Highway Traffic Safety Administration. The results confirm that the adhesion capacities of tires have an opposite effect on lateral vehicle stability and rollover propensity, while both suspension parameters and road excitation inputs significantly influence vehicle rollover and lateral stability. Additionally, we identified a positive correlation between vehicle properties and lateral handling, especially when tire characteristics are considered.

Abstract Energy resources are of strategic interest worldwide. Transportation sector is a principal consumer of different energy resources, therefore reducing the consumption of vital energy resources is critical in automobiles. The friction and wear issues impact the energy efficiency of engines, therefore it is an important development of the lubricant for saving energy. The current study supports that goal. This study deals contribution of Al2O3/TiO2 hybrid nanoparticles as nanolubricants to improve gasoline engine efficiency and fuel economy. The gasoline engine performance characteristics were evaluated experimentally using an AVL dynamometer under different operating conditions including the New European Driving Cycle (NEDC). Additionally, the engine was tested under critical operating conditions (warm-up phase). The results showed that using Al2O3/TiO2 nanolubricants increases the brake power, torque, and mechanical efficiency, while the brake specific fuel consumption (BSFC) reduced owing to the mechanical efficiency of the engine improved by 1.7–2.5%, as compared to the engine oil without nanoparticles. Hence, the vehicle fuel consumption during NEDC could be improved up to 4 L per 100 km in the urban. Furthermore, FESEM, EDS line scanning, XPS, and Raman spectroscopy were conducted to understand the major tribological reasons for improving the engine performance to link tribological tests in the laboratory with actual engine performance. Eventually, the results suggest that nanolubricants provide economical engines with high efficiency that it may be an appropriate direction for vehicle manufacturers and users to suppress the engine fuel cost with engine durability under different operating conditions.

Heavy trucks are mostly used for international transportations, with longer highways and long driving hours contributing to corresponding increases in the driver’s fatigue that is related to accidents. Therefore, this study aims to improve the truck ride performance using multistage leaf springs and semi-active suspension for the driver seat. This analytical study describes the influence of the truck main suspensions on the performance indices analytically using MATLAB Simulink for different loading conditions in three case studies: fully laden articulated truck (case A), unladen truck (case B), and empty semi-trailer and a multistage leaf springs is considered after designing the main leaf spring stiffness based on particle swarm optimization (case C). This study exhibits a contribution based on the fact that changing the trailer cargo weight has considerable effects on the natural frequency of the vibration modes of the vehicle system, particularly for articulated carriage. Subsequently, the influence of the dynamic interaction of an articulated vehicle between the semitrailer and the tractor on its ride behavior has been investigated. The model has also predicted the effect of total trailer cargo on performance indices for 13 degrees of freedom model of a 6-axle articulated truck semi-trailer vehicle with a random road excitation. Additionally, a semi-active driver seat suspension based on skyhook strategy and seat passive suspension are compared in terms of the power spectral density and root mean square values. The results showed that the truck ride performance is improved significantly, and all the acceleration responses are suppressed dramatically when a designed multistage leaf spring suspension is considered in case C. The current analysis demonstrated that using specific and adjustable suspension parameters can positively enhance the riding behavior of the unladen vehicle. The results showed that the cab, tractor, and trailer acceleration improved by 22%, 21%, and 28%, respectively, which provides a comfort driving trip essentially for long distance traveling.

Regenerative shock absorbers (RSAs) have still not entered production lines despite the promising potentials in energy efficiency and emission reduction. Vibration energy harvesting from vehicle dampers has been replicating the dynamics of passive viscous dampers. An accurate frequency-based analysis of the harvestable energy and dynamics for vehicle suspensions under typical operating conditions is essentially needed for designing functional Vibratory Regenerative Dampers (VRDs). This paper proposes frequency-based parametrical bandwidth sensitivity analyses of both the vehicular suspension dynamics and energy harvesting potentiality in accordance with the Monte Carlo sensitivity simulations. This provides insights into which suspension parameter could highly broaden the harvestable power magnitude, which contributes positively to conceptualizing an efficient design of a wide broad-banded energy harvesting damper leading to improved harvesting efficiencies in different road conditions. The conducted sensitivity analysis included the change in both frequency and amplitude bandwidth of the dissipative damping power, body acceleration, dynamic tire load, and suspension deflection. During the sensitivity simulations, a 2-DOFs (degrees-of-freedom) quarter-car model is considered, being excited by harmonic excitations. The selected suspension parameters were normally randomized according to the Gaussian probability distribution based on their nominal values and a 30% SD (standard deviation) with respect to the uniformly randomized excitation frequency. The results inferred higher sensitivity change in the harvestable power bandwidth versus the excitation parameters, damping rate, and tire properties. Conversely, the harvestable power hardly broadened with respect to the body and wheel masses and the spring stiffness.