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The Chevy Bolt’s One Pedal Driving feature is a new electrification propulsion enhancement that allows the driver to accelerate, decelerate and hold their vehicle stationary by just using the accelerator pedal. With this new feature, the driver is relieved of having to switch between pressing the accelerator pedal and brake pedal to slow, stop and hold the vehicle stationary. While this feature provides a convenience to the driver, it also presents a paradigm shift in driver engagement and control system responsibility for executing certain functions that the driver was traditionally responsible to perform. Various system safety techniques were involved in the development of such a feature both from a traditional functional safety perspective as well as a Safety of the Intended Functionality (SOTIF) perspective.

Heat transfer performance of fin-tube heat exchanger can be enhanced by using longitudinal vortex generators which produces longitudinal vortices. In the present work numerical simulations have been performed to investigate the heat transfer and flow resistance characteristics of rectangular winglet pair type vortex generators (VGs) with punched hole of circular shape (RWPH). RWPH have been placed in Common Flow Down (CFD) and Common Flow Up (CFU) configuration in downstream as well as upstream direction. Heat transfer characteristics and flow behavior have been compared for both the configurations i.e. CFD and CFU, in downstream as well as upstream using Colburn’s factor(j), friction factor(f) and performance evaluation criterion, R = (j/j0)/(f/f0)1/3. Simultaneously, Reynolds number have been varied from 1400 to 9000. The punched hole considerably improves the thermohydraulic performance of RWP and decreases the flow resistance due to reduction in face area.

In the pursuit of extracting the most performance, engines are being continuously down sized and their power density continuously increased. This significantly increases the heat load on the engine for which the traditional cooling systems may not be sufficient. In the view of this fact; it is worth to explore controlled nucleate boiling to optimize engine cooling system designs. In order to utilize nucleate boiling in cooling systems, a detailed understanding of single bubble dynamics and its associated heat transfer is essential. In this work, a contact line evaporation model is developed which is then coupled to a conjugate surface to understand the individual contribution of micro layer and other sub processes towards overall heat transfer mechanism. The models use volume of fluid (VOF) interface capturing method and incorporates physics like contact line evaporation, transient conduction and bubble growth.

Adhesive bonding is a key technology for the lighter weight of battery pack trays using aluminum material. A robust design method of adhesive bonding with the required strength for battery pack structure after degradation was developed to minimize variability of strength under various noise conditions. The parameter design based on Taguchi methods determined the optimum adhesive condition of the bonding process. To guarantee strength after degradation, it is essential to select a robust adhesive material and to minimize the strength variation derived from the adhesive material. The functional evaluation, which includes experimental design method, determined adhesive material with the minimum strength variation among material candidates. Then, robustness of the adhesive material itself has been evaluated as the result of collaboration with the adhesive material supplier. This analysis was able to regulate the compound ratio of raw materials without reducing the adhesive strength.

We present an Accelerated Life Testing (ALT) methodology along with a design for fatigue approach, using Gaussian or non-Gaussian excitations. The accuracy of fatigue life prediction at nominal loading conditions is affected by model and material uncertainty. This uncertainty is reduced by performing tests at a higher loading level, resulting in a reduction in test duration. Based on the data obtained from experiments, we formulate an optimization problem to calculate the Maximum Likelihood Estimator (MLE) values of the uncertain model parameters. In our proposed ALT method, we lift all the assumptions on the type of life distribution or the stress-life relationship and we use Saddlepoint Approximation (SPA) method to calculate the fatigue life Probability Density Functions (PDFs).

In this paper we investigate the application of time constant to estimate the external heat transfer coefficient (h) around specific vehicle components. Using this approach, a test sample in the form of a steel plate is placed around the component of interest. A step change is applied to air temperature surrounding the sample. The response of the sample temperature can be analyzed and the heat transfer coefficient can therefore be calculated. Several test samples were installed at several locations in the vehicle under-hood and underbody. A series of vehicle tests were designed to measure the time constant around each component at various vehicle speeds. A correlation between estimated heat transfer coefficients and vehicle speed was generated. The developed correlations and the measured component ambient temperatures can be readily used as input for thermal simulation tools. This approach can be very helpful whenever CFD resources may not be available.

In summer, the relatively low temperature water condenses in the evaporator when the vehicle air-conditioning (AC) is running. At present, the vehicle AC condensate water without well utilization is directly wasted. The condenser’s thermal transfer performance has a great influence on the AC performance, and to increase the convective heat transfer coefficient (CHTC) is the key to its design. In this paper, a method of using atomized condensate water (CW) to enhance the condenser’s thermal transfer performance is proposed, which can make the most of the CW's cold energy. It achieves the reuse of CW and increases the condenser’s CHTC. First, the CW flow calculation model in the evaporator and the calculation model of the condenser enhanced thermal transfer using atomized CW are both set up. The influence of the evaporation degree of atomized CW particles in the air on the enhancement effect is comprehensively considered.

This article discusses highly flexible and accurate physics-based mean value modeling (MVM) for internal combustion engines and its wide applicability towards virtual vehicle calibration. The requirement to fulfill the challenging Real Driving Emissions (RDE) standards has significantly increased the demand for precise engine models, especially models regarding pollutant emissions and fuel economy. This has led to a large increase in effort required for precise engine modeling and robust model calibration. Two best-practice engine modeling approaches will be introduced here to satisfy these requirements. These are the exclusive MVM approach, and a combination of MVM and a Design of Experiments (DOE) model for heterogeneous multi-domain engine systems.

The electromagnetic regenerative suspension has attracted much attention recently due to its potential to improve ride comfort and handling stability, at the same time recover kinetic energy which is typically dissipated in traditional shock absorbers. The key components of a ball-screw regenerative suspension system are a motor, a ball screw and a nut. For this kind of regenerative suspension, its damping character is determined by the motor's torque-speed capacity, which is different from the damping character of the traditional shock absorber. Therefore, it is necessary to establish a systematic approach for the parameter matching of ball-screw regenerative suspension, so that the damping character provided by it can ensure ride comfort and handling stability. In this paper, a 2-DOF quarter vehicle simulation model with regenerative suspension is constructed. The effects of the inertia force on ride comfort and handling stability are analyzed.

Proportional-integral-derivative (PID) controller is effective, popular and cost effective for a lot of scientific and engineering applications. In this paper, PID and fuzzy-self-tuning PID (FSTPID) controllers are applied to improve the performance of an active seat suspension system to enhance the pregnant woman comfort. The equations of motion of thirteen-degrees-of-freedom (13-DOF) active seat suspension system incorporating pregnant woman body model are derived and simulated. PID gains are tuned and estimated using genetic algorithm (GA) to formulate GA PID controller. In FSTPID, fuzzy logic technique is used to tune PID controller gains by selecting appropriate fuzzy rules using Matlab/Simulink software. Both controlled active seat suspension systems are compared with a passive seat suspension. Suspension performance is evaluated under bump and random road excitations in order to verify the success of the proposed controllers.

Excellent energy consumption performance of a plug-in hybrid electric vehicle (PHEV) is usually attributed to its hybrid drive mode. However, the factors including vehicle performance, driver behavior and traffic status have been shown to cause unsatisfactory performance. This phenomenon leads to a necessity of study on energy consumption control strategies under real-world driving conditions. This paper proposes a new approach for energy management optimization of plug-in hybrid electric vehicles based on real-world driving data for two purposes. One is for improving the energy consumption of PHEV under real-world driving conditions and the other is for reducing the computational complexity of optimization methods in simulation models. In this process, the paper collected real-world driving record data from 180 drivers within 6 months. Then the principal component analysis (PCA) was employed to extract and define the hidden factors from the initial real-world driving data.

Numerical investigation of engine performance and emissions of a six-stroke gasoline compression ignition (GCI) engine combustion at low load conditions is presented. In order to identify the effects of additional two strokes of the six-stroke engine cycle on the thermal and chemical conditions of charge mixtures, an in-house multi-dimensional CFD code coupled with high fidelity physical sub-models along with the Chemkin library was employed. The combustion and emissions were calculated using a reduced chemical kinetics mechanism for a 14-component gasoline surrogate fuel. Two power strokes per cycle were achieved using multiple injections during compression strokes. Parametric variations of injection strategy viz., individual injection timing for both the power strokes and the split ratio that enable the control of combustion phasing of both the power strokes were explored.

It is well-known that the spatial distribution of turbulence intensity and fuel concentration at spark-time play a pivotal role on the flame development within the pre-chamber in gas engines equipped with a scavenged pre-chamber. The combustion within the pre-chamber is in turn a determining factor in terms of combustion behaviour in the main chamber, and accordingly it influences the engine efficiency as well as pollutant emissions such as NOx and unburned hydrocarbons. This paper presents a numerical analysis of fuel concentration and turbulence distribution at spark time for an automotive-sized scavenged pre-chamber mounted at the head of a rapid compression-expansion machine (RCEM). Two different pre-chamber orifice orientations are considered: straight and tilted nozzles. The latter introduce a swirling flow within the pre-chamber. Simulations have been carried out using with two different turbulence models: Reynolds-Averaged Navier-Stokes (RANS) and Large-Eddy Simulation (LES).

Engine experiments have revealed the importance of fuel condensation on the emission characteristics of low temperature combustion. However, direct in-cylinder experimental evidence has not been reported in the literature. In this paper, the in-cylinder condensation processes observed in optically accessible engine experiments are first illustrated. The observed condensation processes are then simulated using state-of-the-art multidimensional engine CFD simulations with a phase transition model that incorporates a well-validated phase equilibrium numerical solver, in which a thermodynamically consistent phase equilibrium analysis is applied to determine when mixtures become unstable and a new phase is formed. The model utilizes fundamental thermodynamics principles to judge the occurrence of phase separation or combination by minimizing the system Gibbs free energy.

The Extended Coherent Flamelet Model (ECFM) is limited to lower order upwinding schemes to minimize the numerical discrepancy between species and tracers, which can lead to inaccurate estimates of the progress variable and consequently negative conditional mass fractions in the burned gases after ignition. The recently developed Species-Based ECFM (SB-ECFM) removes the species tracers from the definition of the progress variable, and allows the use of higher order schemes. In this study, SB-ECFM is coupled with the Imposed Stretch Spark Ignition Model (ISSIM) to simulate a spark-ignition engine, the transparent combustion chamber (TCC) engine. To examine the spatial discretization effect and demonstrate the improvement due to using higher order schemes, Reynolds-Averaged-Navier-Stokes (RANS) simulations performed with a first-order upwinding scheme and a second-order central differencing scheme are compared.

Surface film formation is an important phenomenon during spray impingement in a combustion chamber. The film that forms on the chamber walls and piston bowl produces soot post-combustion. While some droplets stick to the wall surface, others splash and interact with the gas present inside the combustion chamber. Accurate prediction of both the film thickness and splashed mass is crucial for surface film model development since it leads to a precise estimation of the amount of soot and other exhaust gases formed. This information could guide future studies aimed at a comprehensive understanding of the combustion process and might enable development of engines with reduced emissions. Dynamic structure Large Eddy Simulation (LES) turbulence model implemented for in-cylinder sprays [1] has shown to predict the flow structure of a spray more accurately than the Reynolds-averaged Navier-Stokes turbulence model.

The increase in computational power in recent times has led to multidimensional computational fluid dynamics (CFD) modeling tools being used extensively for optimizing the diesel engine piston design. However, it is still common practice in engine CFD modeling to use constant uniform boundary temperatures. This is either due to the difficulty in experimentally measuring the component temperatures or the lack of measurements when simulation is being used predictively. This assumption introduces uncertainty in heat flux predictions. Conjugate heat transfer (CHT) modeling is an approach used to predict the component temperatures by simultaneously modeling the heat transfer in the fluid and the solid phase. However, CHT simulations are computationally expensive as they require more than one engine cycle to be simulated to converge to a steady cycle-averaged component temperature.

A three-dimensional model of a diesel engine intake port was established and was verified by steady-flow test. Based on this model, the influence of intake valve lift on the flow capacity of intake port was studied and a design method of maximum valve lift was put forward. The results show that, under different intake pressure and relative pressure difference conditions, the discharge coefficient increases first and then converges with the increase of valve lift. Under the same valve lift condition, with the increase of relative pressure difference, the discharge coefficient decreases slightly in subsonic state and decreases sharply from subsonic state to supersonic state, but the mass flow rate increases slightly. The optimum ratio of valve lift and valve seat diameter is related to relative pressure difference, it increases first and then keeps constant with the increase of relative pressure difference.

Prognosis is used to improve system availability. This is achieved by minimizing system downtime with the help of mechanisms that senses the degradation in the system health to predict the ‘time-to-failure’ of the system. Degradation in the system’s health is measured by sensing the early signs of aging and wear and tear of the system components. This requires knowledge of all the failure modes of the system along with patterns of behavioral changes in the individual components of the system while it continues to age. Prognosis methods and mechanisms are still evolving. So, no comprehensive guidelines or framework standards exist as of today that can provide reliable and standardized prognosis solutions to the end user customers. The intent of devising such a framework and guidelines is to improve and standardize the implementation of prognosis solutions so that; it will be more effective to all stakeholders from the perspective of safety, cost and convenience.

With increasing road traffic and pollution, it becomes responsibility for all OEM to increase fuel efficiency and reduce carbon footprint. Most effective way to do so is to reduce weight of the vehicle and more use of ecofriendly recyclable material. With this objective we have come up with Light weight, cost effective sustainable design solution for Injection moulded RQT (Rear quarter trim). It is an interior plastic component mounted in the III row of the vehicle. This is required to ensure inside enhanced aesthetic look of the vehicle and comfort for 3rd row passengers. Conventionally RQT of vehicle with 3rd row seating is made using plastic material (PP TD 20). With the use of plastic moulded RQT there is a significant weight addition of around 6 kg per vehicle along with reduced cabin space, huge investment and development time impact.