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Technical Paper

Automated Park and Charge: Concept and Energy Demand Calculation

2024-07-02
2024-01-2988
In this paper we are presenting the concept of automated park and charge functions in different use scenarios. The main scenario is automated park and charge in production and the other use scenario is within automated valet parking in parking garages. The automated park and charge in production is developed within the scope of the publicly funded project E-Self. The central aim of the project is the development and integration of automated driving at the end-of-line in the production at Ford Motor Company's manufacturing plant in Cologne. The driving function thereby is mostly based upon automated valet driving with an infrastructure based perception and action planning. Especially for electric vehicles the state of charge of the battery is critical, since energy is needed for all testing and driving operations at end-of-line.
Technical Paper

Software-supported Processes for Aerodynamic Homologation of Vehicles

2024-07-02
2024-01-3004
Homologation is an important process in vehicle development and aerodynamics a main data contributor. The process is heavily interconnected: Production planning defines the available assemblies. Construction defines their parts and features. Sales defines the assemblies offered in different markets, where Legislation defines the rules applicable to homologation. Control engineers define the behavior of active, aerodynamically relevant components. Wind tunnels are the main test tool for the homologation, accompanied by surface-area measurement systems. Mechanics support these test operations. The prototype management provides test vehicles, while parts come from various production and prototyping sources and are stored and commissioned by logistics. Several phases of this complex process share the same context: Production timelines for assemblies and parts for each chassis-engine package define which drag coefficients or drag coefficient contributions shall be determined.
Technical Paper

Frequency Response Analysis of Fully Trimmed Models using Compressed Reduced Impedance Matrix Methodology

2024-06-12
2024-01-2947
As vibration and noise regulations become more stringent, numerical models need to incorporate more detailed damping treatments. Commercial frameworks, such as Nastran and Actran, allow the representation of trim components as frequency-dependent reduced impedance matrices (RIM) in frequency response analysis of fully trimmed models. The RIM is versatile enough to couple the trims to modal-based or physical components. If physical, the trim components are reduced on the physical coupling degrees of freedom (DOFs) for each connected interface. If modal, the RIMs are projected on the eigenmodes of the connected component. While a model size reduction is achieved compared to the original model, most numerical models possess an extensive number of interfaces DOFs, either modal or physical, leading to large dense RIM which triggers substantial memory and disk storage.
Technical Paper

Development of a Hybrid-Electric Medium-HD Demonstrator Vehicle with a Pent-Roof SI Natural Gas Engine

2024-06-12
2024-37-0026
In response to global climate change, there is a widespread push to reduce carbon emissions in the transportation sector. For the difficult to decarbonize heavy-duty (HD) vehicle sector, lower carbon intensity fuels can offer a low-cost, near-term solution for CO2 reduction. The use of natural gas can provide such an alternative for HD vehicles while the increasing availability of renewable natural gas affords the opportunity for much deeper reductions in net-CO2 emissions. With this in consideration, the US National Renewable Energy Laboratory launched the Natural Gas Vehicle Research and Development Project to stimulate advancements in technology and availability of natural gas vehicles. As part of this program, Southwest Research Institute developed a hybrid-electric medium-HD vehicle (class 6) to demonstrate a substantial CO2 reduction over the baseline diesel vehicle and ultra-low NOx emissions.
Technical Paper

Ducted Fuel Injection: Confirmed Re-entrainment Hypothesis

2024-04-09
2024-01-2885
Testing of ducted fuel injection (DFI) in a single-cylinder engine with production-like hardware previously showed that adding a duct structure increased soot emissions at the full load, rated speed operating point [1]. The authors hypothesized that the DFI flame, which travels faster than a conventional diesel combustion (CDC) flame, and has a shorter distance to travel, was being re-entrained into the on-going fuel injection around the lift-off length (LOL), thus reducing air entrainment into the on-going injection. The engine operating condition and the engine combustion chamber geometry were duplicated in a constant pressure vessel. The experimental setup used a 3D piston section combined with a glass fire deck allowing for a comparison between a CDC flame and a DFI flame via high-speed imaging. CH* imaging of the 3D piston profile view clearly confirmed the re-entrainment hypothesis presented in the previous engine work.
Technical Paper

Research on the Pollutant Reduction Control for P2.5 Hybrid Electric Vehicles

2024-04-09
2024-01-2376
The strategy for emission reduction in the P2.5 hybrid system involves the optimization of engine torque, engine speed, catalyst heat duration, and motor torque regulation in a coordinated manner. In addition to employing traditional engine control methods used in HEV models, unique approaches can be utilized to effectively manage emissions. The primary principle is to ensure that the engine operates predominantly under steady-state conditions or limits its load to regulate emissions levels. The main contributions of this paper are as follows: The first is the optimization of catalyst heating stage. During the catalyst heating stage, the system divides it into one or two stages. In the first stage, the vehicle is driven by the motor while keeping the engine idle. This approach stabilizes catalyst heating and prevents fluctuations in air-fuel ratio caused by speed and load changes that could potentially worsen emissions performance.
Technical Paper

3D CFD Modeling of an Electric Motor to Predict Spin Losses at Different Temperatures

2024-04-09
2024-01-2208
With the advent of this new era of electric-driven automobiles, the simulation and virtual digital twin modeling world is now embarking on new sets of challenges. Getting key insights into electric motor behavior has a significant impact on the net output and range of electric vehicles. In this paper, a complete 3D CFD model of an Electric Motor is developed to understand its churning losses at different operating speeds. The simulation study details how the flow field develops inside this electric motor at different operating speeds and oil temperatures. The contributions of the crown and weld endrings, crown and weld end-windings, and airgap to the net churning loss are also analyzed. The oil distribution patterns on the end-windings show the effect of the centrifugal effect in scrapping oil from the inner structures at higher speeds. Also, the effect of the sump height with higher operating speeds are also analyzed.
Technical Paper

Optimization of BEV and FCEV Storage Design Based on Automated Packaging and Vehicle Simulation

2024-04-09
2024-01-2178
Electrified vehicles represent mobility’s future, but they impose challenging and diverse requirements like range and performance. To meet these requirements, various components, such as battery cells, electric drives, fuel cells, and hydrogen vessels need to be integrated into a drive and storage system that optimizes the key performance indicators (KPI). However, finding the best combination of components is a multifaceted problem in the early phases of development. Therefore, advanced simulation tools and processes are essential for satisfying the customer´s expectation. EDAG Engineering GmbH has developed a flat storage platform, which is suitable for both, BEV and FCEV. The platform allows for the flexible and modular integration of batteries and hydrogen vessels. However, package space is limited and the impact of the design choices regarding the vehicle’s KPI need to be considered.
Technical Paper

Integrated Bracket for Rain Light Sensor/ADAS/Auto-Dimming IRVM with provision of mounting for Aesthetic Cover

2024-04-09
2024-01-2224
Plastic design is one of the upcoming fields of interest when it comes to weight optimization, sustainability, strength, and overall aesthetics of an automobile. What is often ignored is the amount of flexibility a plastic designer has, of integrating and packaging various components of an automobile into a single part and still make it an integral part of its complex aesthetics. This paper highlights upon one such part that is being developed: An integrated bracket which packages ADAS camera, Rain Light Sensor, and an Auto-dimming IRVM. Apart from packaging the mentioned components, this bracket also has mounting provisions for an aesthetic cover (also referred to as beauty cover). The objective of this paper is to highlight the importance of integration of several parts into a single part for packaging multiple components that need to be placed in a close proximity with each other.
Technical Paper

Expanding the Use of Vehicle Specific Power in Analysis of Platoon Performance

2024-04-09
2024-01-2057
Platooning is a coordinated driving strategy by which following trucks are placed into the wake of leading vehicles. Doing this leads to two primary benefits. First, the vehicles following are shielded from aerodynamic drag by a “pulling” effect. Secondly, by placing vehicles behind the leading truck, the leading vehicles experience a “pushing” effect. The reduction in aerodynamic drag leads to reduced fuel usage and, consequently, reduced greenhouse gas emissions. To maximize these effects, the inter-vehicle distance, or headway, needs to be minimized. In current platooning strategy iterations, Coordinated Adaptive Cruise Control (CACC) is used to maintain close following distances. Many of these strategies utilize the fuel rate signal as a controller cost function parameter. By using fuel rate, current control strategies have limited applicability to non-conventional powertrains.
Technical Paper

Art Meets Automotive: Design of a Curve-Adaptive Origami Gripper for Handling Textiles on Non-Planar Mold Surfaces

2024-04-09
2024-01-2575
The handling of flexible components creates a unique problem set for pick and place automation within automotive production processes. Fabrics and woven textiles are examples of flexible components used in car interiors, for air bags, as liners and in carbon-fiber layups. These textiles differ greatly in geometry, featuring complex shapes and internal slits with varying material properties such as drape characteristics, crimp resistance, friction, and fiber weave. Being inherently flexible and deformable makes these materials difficult to handle with traditional rigid grippers. Current solutions employ adhesive, needle-based, and suction strategies, yet these systems prove a higher risk of leaving residue on the material, damaging the weave, or requiring complex assemblies. Pincer-style grippers are suitable for rigid components and offer strong gripping forces, yet inadvertently may damage the fabric, and introduce wrinkles / folded-over edges during the release process.
Technical Paper

A Study of Compression Pad, Its Selection and Optimization Process for the Lithium-Ion Cell Module

2024-04-09
2024-01-2430
The need for eco-friendly vehicle powertrains has increased drastically in recent years. The most critical component of an electric vehicle is the battery pack/cell. The choice of the appropriate cell directly determines the size, performance, range, life, and cost of the vehicle. Lithium-ion batteries with high energy density and higher cycle life play a crucial role in the progress of the electric vehicle. However, the packaging of lithium-ion cells is expected to meet lots of assembly demands to increase their life and improve their functional safety. Due to their low mechanical stability, the lithium-ion cell modules must have external pressure on the cell surface for improved performance. The cells must be stacked in a compressed condition to exert the desired pressure on the cell surface using compression foam/pads. The compression pads can be either packaged between each cell or once in every set of cells based on the cell assembly requirements.
Technical Paper

Drag Reduction Study on Vehicle Shape Optimization Using Gradient-based Adjoint Method

2024-04-09
2024-01-2528
Given the increasingly stringent environmental regulations, most automotive manufacturers were confronted with tougher exhaust emission and energy consumption standards, thus, improving fuel economy has been the top priority for OEMs during the past few years. In this context, it is quite essential to improve the aerodynamic characteristics, especially drag reduction in vehicle shape development, considering its close correlation with fuel consumption and E-range. Of all the optimization approaches, the gradient-based adjoint method has currently received growing attention for its proven effectiveness in calculating the drag sensitivity with respect to geometry parameters, which is indispensable for subsequent shape modification. In this work, we aim to utilize the adjoint approach to optimize the vehicle shape for a lower drag on the DrivAer models.
Technical Paper

The Aerodynamic Development of the New BREZZA and FRONX

2024-04-09
2024-01-2535
MSIL (Maruti Suzuki India Limited), India’s leading carmaker, has various SUVs (Sports Utility Vehicle) in its model lineup. Traditionally, SUVs are considered to have a bold on-road presence and this bold design language often deteriorates aerodynamic drag performance. Over the years, the demand for this segment has significantly grown, whereas the CAFE (Corporate Average Fuel Economy) norms have become more stringent. To cater this growing market demand, MSIL planned for two new SUVs: (1) New BREZZA - A bolder design with similar targeted aerodynamic performance compared to its predecessor (BREZZA-2016) and (2) FRONX - A new cross-over SUV vehicle targeted best-in-class aerodynamic performance in this category at MSIL. This paper illustrates the aerodynamic development process for these two SUVs using CFD (Computational Fluid Dynamics) and full scale WTT (Wind Tunnel Test).
Technical Paper

Wheel Air Drag Prediction Technique Using WAD Parameter

2024-04-09
2024-01-2538
Wheel drag is generally known to be proportional to the wheel opening area. However, predicting wheel drag through opening area is still very difficult and inaccurate because there are many other factors that affect wheel drag. To more accurately and effectively predict wheel drag in the early styling design stage, we introduced the wheel average depth (WAD) parameter and developed S/W to calculate WAD. As a result of analyzing the correlation between WAD and wheel drag for HKMC's mass-produced wheels, the R2 value was greatly improved compared to the correlation between the existing wheel opening area and wheel drag, and the prediction accuracy was doubled.
Technical Paper

Development, Application, and Implementation of Passenger Vehicle Wind Averaged Drag for Vehicle Development

2024-04-09
2024-01-2532
A new methodology is discussed for the development and implementation of a wind-averaged drag analysis technique for the development of aerodynamic-driven surfaces for use in the automotive industry. Current methods of vehicle design focus on reducing the straight-line coefficient of drag using wind tunnel testing and computational fluid dynamics and quote this value as the vehicle's aerodynamic performance. It is suggested to transition passenger vehicle aerodynamic design to the methodology employed for Class-A vehicles and design with a focus on reducing the wind-averaged drag value. Based on the methods used in J1252, the wind averaged drag calculation method utilizes the average wind speed a vehicle will experience in the continental United States and assumes an equal probability of the wind coming from all directions relative to the vehicle. Wind-averaged drag will optimize vehicle design for real-world improvements of vehicle efficiency.
Technical Paper

A Mechanical Energy Control Volume Approach Applied to CFD Simulations of Road Vehicles

2024-04-09
2024-01-2524
This paper presents a mechanical energy control volume analysis for incompressible flow around road vehicles using results from Detached Eddy Simulation Computational Fluid Dynamics calculations. The control volume approach equates the rate of work done by surface forces of the vehicle to (i) the rate of work and kinetic energy flux at the control volume boundaries (particularly in the vehicle wake) and (ii) the rate of energy loss in the domain. At the downstream control volume boundary, the wake terms can be divided into lift-induced and profile drag terms. The rate of energy loss in the domain can be used as a volumetric analog for drag (drag counts/m3, when normalized). This allows for a quantitative break down of the contributions of different flow features/regions to the overall drag force.
Technical Paper

Effect of Cooling Airflow Intake Positioning on the Aerodynamics of a Simplified Battery Electric Road Vehicle

2024-04-09
2024-01-2521
The transition towards battery electric vehicles (BEVs) has increased the focus of vehicle manufacturers on energy efficiency. Ensuring adequate airflow through the heat exchanger is necessary to climatize the vehicle, at the cost of an increase in the aerodynamic drag. With lower cooling airflow requirements in BEVs during driving, the front air intakes could be made smaller and thus be placed with greater freedom. This paper explores the effects on exterior aerodynamics caused by securing a constant cooling airflow through intakes at various positions across the front of the vehicle. High-fidelity simulations were performed on a variation of the open-source AeroSUV model that is more representative of a BEV configuration. To focus on the exterior aerodynamic changes, and under the assumption that the cooling requirements would remain the same for a given driving condition, a constant mass flow boundary condition was defined at the cooling airflow inlets and outlets.
Technical Paper

Sulfur Impact on Methane Steam Reforming over the Stoichiometric Natural Gas Three-Way Catalyst

2024-04-09
2024-01-2633
The steam reforming of CH4 plays a crucial role in the high-temperature activity of natural gas three-way catalysts. Despite existing reports on sulfur inhibition in CH4 steam reforming, there is a limited understanding of sulfur storage and removal dynamics under various lambda conditions. In this study, we utilize a 4-Mode sulfur testing approach to elucidate the dynamics of sulfur storage and removal and their impact on three-way catalyst performance. We also investigate the influence of sulfur on CH4 steam reforming by analyzing CH4 conversions under dithering, rich, and lean reactor conditions. In the 4-Mode sulfur test, saturating the TWC with sulfur at low temperatures emerges as the primary cause of significant three-way catalyst performance degradation. After undergoing a deSOx treatment at 600 °C, NOx conversions were fully restored, while CH4 conversions did not fully recover.
Technical Paper

Experimental Investigation of Low-Frequency Flow Phenomena on the Vehicle Underbody Using Particle Image Velocimetry

2024-04-09
2024-01-2546
The increasing importance of minimizing drag and the absence of an exhaust system result in battery electric vehicles (BEVs) commonly having a very streamlined underbody. Although this shape of underbody is typically characterized by a low acoustic interference potential, significant flow resonance can be observed for certain vehicle configurations and frequencies below 30 Hz. Since the interior of the vehicle can be excited as a Helmholtz resonator, these low-frequency fluctuations result in reduced comfort for the passengers. As preliminary studies have shown, the flow around the front wheel spoilers significantly influences this flow phenomenon. Flow separation occurs at the front-wheel spoilers and at the front wheels. This leads to the generation of vortices which are growing significantly while being transported downstream with the flow. Even small geometric changes to add-on components on the underbody significantly influence both aerodynamics and aeroacoustics.
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