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Technical Paper

Assessing the Effects of Computational Model Parameters on Aerodynamic Noise Characteristics of a Heavy-Duty Diesel Engine Turbocharger Compressor at Full Operating Conditions

2024-04-09
2024-01-2352
In recent years, with the development of computing infrastructure and methods, the potential of numerical methods to reasonably predict aerodynamic noise in compressors has increased. However, aerodynamic acoustic modeling of complex geometries and flow systems is currently immature, mainly due to the greater challenges in accurately characterizing turbulent viscous flows. Therefore, recent advances in aerodynamic noise calculations for automotive turbocharger compressors were reviewed and a quantitative study of the effects for turbulence modeling (Shear-Stress Transport (SST) and Detached Eddy Simulation (DES)) and time-steps (2°and 4°) in numerical simulations on the performance and acoustic prediction of a compressor under full operating conditions was investigated. The results showed that for the compressor performance, the turbulence models and time-step parameters selection were within 1.5% error of the simulated and measured values for pressure ratio and efficiency.
Technical Paper

Active Damping Control & Architecture within a Hybrid Supervisor Control Structure

2024-04-09
2024-01-2144
This paper focuses on an inherent problems of active damping control prevalent in contemporary hybrid torque controls. Oftentimes, a supervisory torque controller utilizes simplified system models with minimal system states representation within the optimization problem, often not accounting for nonlinearities and stiffness. This is motivated by enabling the generation of the optimum torque commands with minimum computational burden. When inherent lash and stiffness of the driveline are not considered, the resulting command can lead to vibrations and oscillations in the powertrain, reducing performance and comfort. The paper proposes an LQI-based compensator to be integrated downstream the torque supervisory algorithm, which role is to shape transient electric machine torques, compensating for the stiffness & backlash present in the vehicle while delivering the driver-requested wheel torque.
Technical Paper

The Basis of Automotive Engineering Accelerated Testing

2024-04-09
2024-01-2425
This paper revised the current situation in development of the accelerated testing of automotive engineering that consists of the four following areas: 1.Field testing of the natural product. 2. Additional technology of separate testing in the laboratory on the basis of physical simulation of separate field conditions with using corresponding methods and equipment separately and conducting: safety testing, special programs of testing using digital simulation, special testing with changing certain parameters of environment, corrosion testing, etc. Both of the traditional testing developments above can be found in many magazines, journals, conferences presentations and proceedings. 3. Testing on the basis of digital (computer) simulation of product and/or field conditions. This area of testing ihas especially developed in the last dozen years. Many articles and presentations were published during this time. 4.
Technical Paper

Fourth Axle Steering Control Strategies of an 8x8 Scaled Electric Combat Vehicle

2024-04-09
2024-01-2763
With the rise in demand, advanced steering control and electric vehicle technology are rapidly developing in modern times. Due to a controller's role as a backbone for the modern vehicle, its study has become increasingly crucial. This study investigates Ackermann's condition and active 4th axle steering control strategies of an 8x8 scaled electric combat vehicle with a predefined path following. Two different rear steering methods - Fourth axle steering (fixed third axle) and All-wheel steering - are applied to Ackermann condition and active 4th axle steering control strategies. In the scaled vehicle, each wheel is independently driven by an in-wheel motor, while the steering is carried out by linear actuators. Individual eight-wheel steering control systems are designed and installed on the scaled vehicle to evaluate the driving performance from low speed to high speed.
Technical Paper

Development of Time-Temperature Analysis Algorithm for Estimation of Lithium-Ion Battery Useful Life

2024-04-09
2024-01-2191
Due to the recent progress in electrification, lithium-ion batteries have been widely used for electric and hybrid vehicles. Lithium-ion batteries exhibit high energy density and high-power density which are critical for vehicle development with high driving range enhanced performance. However, high battery temperature can negatively impact the battery life, performance, and energy delivery. In this paper, we developed and applied an analytical algorithm to estimate battery life based vehicle level testing. A set of vehicle level tests were selected to represent customer duty cycles. Thermal degradation models are applied to estimate battery capacity loss during driving and park conditions. Due to the sensitivity of Lithium-Ion batteries to heat, the effect of high ambient temperatures throughout the year is considered as well. The analysis provides an estimate of the capacity loss due to calendar and cyclic effects throughout the battery life.
Technical Paper

A Special User Shell Element for Coarse Mesh and High-Fidelity Fatigue Modeling of Spot-Welded Structures

2024-04-09
2024-01-2254
A special spot weld element (SWE) is presented for simplified representation of spot joints in complex structures for structural durability evaluation using the mesh-insensitive structural stress method. The SWE is formulated using rigorous linear four-node Mindlin shell elements with consideration of weld region kinematic constraints and force/moments equilibrium conditions. The SWEs are capable of capturing all major deformation modes around weld region such that rather coarse finite element mesh can be used in durability modeling of complex vehicle structures without losing any accuracy. With the SWEs, all relevant traction structural stress components around a spot weld nugget can be fully captured in a mesh-insensitive manner for evaluation of multiaxial fatigue failure.
Technical Paper

Enhancing ducted fuel injection simulations: assessment of RANS turbulence models using LES data

2024-04-09
2024-01-2689
Diesel engine-based transportation is nowadays looking for cleaner combustion solutions and ducted fuel injection (DFI) is emerging as a cutting-edge technology due to its potential to drastically curtail engine-out soot emissions. Although the DFI capability to abate soot formation throughout the diesel combustion process has been demonstrated both in constant-volume and optical engine conditions, its optimization and understanding is still needed for its exploitation on series production diesel engines. For this purpose, computational fluid dynamics (CFD) coupled with low-cost turbulence models, like RANS, can be a powerful tool, especially in the industrial context. However, it is often challenging to obtain reliable RANS-based CFD simulations, especially due to the high dependence of the various state-of-the-art turbulence models on the case study.
Technical Paper

Introduction of the eGTU – an electric version of the Generic Truck Utility Aerodynamic Research Model

2024-04-09
2024-01-2273
Common aerodynamic research models have been used in aerodynamic research throughout the years to assist with the development and correlation of new testing and numerical techniques, in addition to being excellent tools for gathering fundamental knowledge about the physics around the vehicle. In 2020, the Generic Truck Utility (GTU) was introduced by Woodiga et al. following the success of the DrivAer, originally introduced by Heft et al. in 2012, in the automotive aerodynamics space but with a goal to capture the unique flow fields created by pickups and large SUVs. To date, a number of studies have been presented on the GTU (Howard et. al 2021, Gleason, Eugen 2022), however, with the increasing prevalence of electric vehicles (EVs), the authors have created additional configurations to create an EV-style underbody for the GTU. The existing GTU can change the cab and box lengths independently and has a rear cap with three different backlight angles to model SUVs.
Technical Paper

A method of generating a composite dataset for driver behavior monitoring

2024-04-09
2024-01-2640
Recently, several datasets have become available for occupant monitoring algorithm development, including real and synthetic datasets. However, real data acquisition is expensive and labeling is complex, while virtual data may not accurately reflect actual human physiology. To address these issues and obtain high-fidelity data for training intelligent driving monitoring systems, we have constructed a hybrid dataset that combines real driving image data with corresponding virtual data generated from 3D driving scenarios. We have also taken into account individual anthropometric measures and driving postures. Our approach not only greatly enriches the dataset by using virtual data to augment the sample size, but it also saves the need for extensive annotation efforts. Besides, we can enhance the authenticity of the virtual data by applying ergonomics techniques, which is crucial in dataset construction.
Technical Paper

Control Strategy for Engine Silicone Oil Fan Clutch Based on Engine Cooling System

2024-04-09
2024-01-2234
In order to study the influence of engine silicone oil fan clutch on the performances of engine cooling system under different control strategies, a model of engine cooling system for commercial vehicle is established. The working characteristics of the silicone oil clutch and the measured performance parameters of the cooling system components are taken into account in our proposed model. Modeling methods for different silicone oil fan control strategies are also given. Using the established model, the performance parameters under different vehicle speeds, such as engine outlet coolant temperature and cooling fan power consumption, are calculated and analyzed. The in-suite measurement of the engine cooling system is carried out to get the temperatures of engine inlet and outlet from engine ECU. The model is validated by the comparison between the calculation and the measured results.
Technical Paper

Reference Velocity Estimation with Variable Gain Based on Powertrain Dynamics for Hybrid Electric Vehicle

2024-04-09
2024-01-2147
Reference velocity (i.e. the absolute velocity of vehicle center of mass) is a key parameter for vehicle stability functions such as the traction control system, anti-lock brake system, acceleration slip regulation, etc. It’s also a key parameter for longitudinal drive control functions of hybrid electric vehicle (HEV) such as the energy management, powertrain mode/gear shifting, drive and regenerative torque control, etc. Most reference velocity estimation methods employ the vehicle kinematics and tire dynamics equations to construct high order linear or quasi-linear system model with a set of parameters and sensor signals. When using those models, delicate estimation algorithm should be designed since the estimates tend to deviate along with the increase of nonlinearity, uncertainty and noise that introduced by high order, number of parameters and sensors, respectively.
Technical Paper

Split Ring Resonator-based Metamaterial with Total Bandgap for Reducing NVH in Electric Vehicles

2024-04-09
2024-01-2348
In this paper, we propose a novel Split Ring Resonator (SRR) metamaterial capable of achieving a total bandgap in the material’s band structure, thereby reflecting air-borne and structure-borne noise in a targeted frequency range. Electric Vehicles (EVs) experience tonal excitation arising from the switching frequencies associated with motors and inverters, which affects occupant perception of vehicle quality. Recently proposed metamaterial designs isolate either air-borne noise or structure-borne noise, but not both. To achieve isolation of both air-borne and structure-borne acoustic energy associated with these tonal frequencies, we propose a metamaterial supercell with transverse and longitudinal resonant frequencies falling in the desired bandwidth of the total bandgap. We calculate the resonant frequencies and corresponding mode shapes using Finite Element (FE) modal analysis.
Technical Paper

1D Modeling Approach for Prediction of Heat Transfer in Aftertreatment System and Sensors Module

2024-04-09
2024-01-2739
The study of temperature distribution and heat transfer over non-uniform geometry is of great importance to engineers because of universal occurrence in many engineering applications such as diesel engine, boilers, heaters, radiators, dosers, etc. Performance of engine and its components (mechanical and electronic) is highly depending upon efficient thermal management. An accurate heat transfer analysis is necessary in automotive application and power plant. This study presents one dimensional model for prediction of conjugate heat transfer in Aftertreatment system and Sensors Module (Nox Sensor, PM Sensor, EGTS etc..) for diesel engine. Three-dimensional conductive, convective and radiative thermal analysis is computationally expensive as underhood models are of complex shape in nature and total turnaround time for product development project is also significantly high.
Technical Paper

Virtual validation of water drip test for non-sealed automotive electronic products towards Ingress Protection requirements

2024-04-09
2024-01-2743
Abstract Modern automobiles are dependent on complex networks of electronic sensors and controls for its efficient and safe operation. These electronic modules are tested for stringent environmental load conditions where product validation consists of one or combination of loads such as Vibration , Mechanical Shock , Temperature , Water , Humidity , Dust , Chemicals and Radiation. Exposure of electronics to water leads to many harmful effects resulting in failure of electronic systems. Previously published technical paper SAE 2023-01-0157 described a methodology to estimate risk in a humid environment , where water is dispersed in air as a gas phase. Present paper extends the scope of virtual validation using Computational Fluid Dynamics (CFD) simulation tools to an environment with water in liquid phase.
Technical Paper

Investigation of Propagation of Viruses and Risk of Infection in Automobile Cabins

2024-04-09
2024-01-2579
The author has developed UV based photocatalytic air purification system (Mathur, 2021, 2023) that can eliminate all pathogens from the cabin air including COVID-19. In this study, the focus is to determine the risk of infection due to pathogens/germs in the cabin of an automobile. Author has determined the risk of infection by using Wells-Riley model and the conducted CFD analysis to determine propagation of virus in cabin.: 1. Cabin Volume & Number of Occupants (Wells-Riley Model in OSA mode): (i) Cabin volume from: Small Sedan, Large Sedan and a SUV; with 4 occupants (males & females); Number of infector 1; Air flowrate (m3/min); (ii) A 15-seater minibus - with 10 occupants(males); Number of infectors 1 & 2; Air flowrate (m3/min) 2.
Technical Paper

Wheel drive unit lift corrections in automotive wind tunnels

2024-04-09
2024-01-2544
Correct simulations of rotating wheels are essential for accurate aerodynamic investigations of passenger vehicles. Therefore, modern automotive wind tunnels are equipped with five-belt moving ground systems with wheel drive units (WDUs) connected to the underfloor balance. The pressure distribution on the exposed areas of the WDU belts results in undesired lift forces being measured which must be considered to obtain accurate lift values for the vehicle. This work investigates the parasitic WDU lift for various configurations of a crossover SUV using numerical simulations that have been correlated to wind tunnel data. Several parameters were considered in the investigation, such as WDU size, WDU placement, tyre variants and vehicle configurations. The results show that the parasitic lift is more sensitive to the width than the length of the WDU. However, the belt length is also important to consider, especially if the wheel cannot be placed centred.
Technical Paper

Analysis of Dual Fuel Hydrogen/Diesel Combustion Varying Diesel and Hydrogen Injection Parameters in a Single Cylinder Research Engine

2024-04-09
2024-01-2363
In the perspective of a reduction of emissions and a rapid decarbonization, especially for compression ignition engines, hydrogen plays a decisive role. The dual fuel technology is perfectly suited to the use of hydrogen, a fuel characterized by great energy potential. In fact, replacing, at the same energy content, the fossil fuel with a totally carbon free one, a significant reduction of the greenhouse gases, like carbon dioxide and total hydrocarbon, as well as of the particulate matter can be obtained. The dual fuel with indirect injection of gaseous fuel in the intake manifold, involves the problem of hydrogen autoignition. In order to avoid this difficulty, the optimal conditions for the injection of the incoming mixture into the cylinder were experimentally investigated. All combustion processes have been carried out on a research engine with optical access. The engine speed has been set at 1500 rpm, while the EGR valve has been deactivated.
Technical Paper

Signature-enriched Vehicle Planning and Control

2024-04-09
2024-01-2559
This work puts forward an original autonomous planning and control framework addressing inherent modeling complexity limit through efficient heterosis between latency-connective graph estimation and generative exploration with an aim to enhance trajectory quality and resiliency in unpredicted conditions. The holistic approach encompasses state and cost prediction facilitated via morphable signature mechanism utilizing anti-cloak characteristics derived from environmental graph. In principle, a dynamic graph neural network is proposed with regards to adaptively capture essential influence caused by interactive agents and reciprocal belief augmentation. Moreover, high efficiency exploration is concerted with signature-enhanced prediction system for non-ideal perception conditions. The exploration scheme takes advantage of confidence optimization function to generate trajectory refinement over non-conventional operating circumstances.
Technical Paper

Study and Analysis on 3-Dimensional Simulation of The Transient Flow Process of Engine Electronic Control Throttle

2024-04-09
2024-01-2417
Based on the basic structure and operation function of engine throttle, according to the actual structure of a throttle, a 3-dimensional simulation of the transient airflow during the rotation of the throttle from the closed position to the fully open position is realized by using CFD together with the moving mesh technology and the user-defined program. The influence of the throttle movement on the airflow process is studied. The velocity field, pressure field, and flow noise field are analyzed at different angles of throttle rotation. The numerical simulation results show that at the beginning period of the throttle rotation, the vortex appears in the flow field behind the throttle, and the drop of the air pressure between the front and back of the throttle is sharp.
Technical Paper

Impact of Injection Valve Condition on Data-driven Prediction of Key Combustion Parameters Based on an Intelligent Diesel Fuel Injector for Large Engine Applications

2024-04-09
2024-01-2836
The advent of digitalization opens up new avenues for advances in large internal combustion engine technology. Key engine components are becoming "intelligent" through advanced instrumentation and data analytics. By generating value-added data, they provide deeper insight into processes related to the components. In addition, these data form the basis for novel condition monitoring, predictive maintenance and controls approaches. Changes to the intelligent component’s operational characteristics due to wear or faults pose a particular challenge for developers of such approaches for later series application. A previous study has already demonstrated that an intelligent common rail diesel fuel injection valve for large engine applications in combination with machine learning allows reliable prediction of key combustion parameters such as maximum cylinder pressure, combustion phasing and indicated mean effective pressure.
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