The increasing awareness on the harmful effects on the environment of traditional Internal Combustion Engines (ICE) is driving the industry toward cleaner powertrain technologies such as battery-driven Electric Vehicles. Nonetheless, the high energy density of Li-Ion batteries can cause strong exothermic reactions under certain conditions that can lead to catastrophic results, called Thermal Runaway (TR). Hence, a strong effort is being placed on understanding this phenomena and increase battery safety. Specifically, the vented gases and their ignition can cause the propagation of this phenomenon to adjancent batteries in a pack. In this work, Computational Fluid Dynamics (CFD) are employed to predict this venting process in a LG18650 cylindrical battery. The ejection of the generated gases was considered to analyze its dispersion in the surrounding volume through a Reynolds-Averaged Navier-Stokes (RANS) approach.
Photographs and video recordings of vehicle crashes and accident sites are more prevalent than ever, with dash mounted cameras, surveillance footage, and personal cell phones now ubiquitous. The information contained in these pictures and videos provide critical information to understanding how crashes occurred, and analyze physical evidence. This course teaches the theory and techniques for getting the most out of digital media, including correctly processing raw video and photographs, correcting for lens distortion, and using photogrammetric techniques to convert the information in digital media to usable scaled three-dimensional data.
Churning loss is an important energy loss term for rolling bearings at high speed condition. However, it is quite challenging to accurately calculate the churning loss. A CFD study based on unsteady Reynolds-Averaged-Navier-Stokes that resolves the gas-liquid interface was performed to examine the unsteady multiphase flow in a roller/ball bearing. In this study, the rotating motion of the cage, races, rollers/balls about the shaft as well as self-rotation of rollers/balls about their own axis were accounted to accurately predict the oil distribution in various parts of the bearings. A novel meshing strategy is presented to resolve thin gaps between the roller/balls and the races/cage while preserving the shape of balls/rollers, races and cage. Seven and five rotational speeds of the shaft have been examined for roller bearing and ball bearing respectively.
The passive pre-chamber is valued for its jet ignition and is widely used in the field of gasoline direct injection (GDI) for small passenger cars, which can improve the performance of lean combustion. However, the scavenging and ignition combustion stability of the engine at low speed is a shortcoming that has not been overcome. Simply changing the structural design to increase the fluidity of MC and PC may lead to a reduction in jet ignition performance, which in turn will affect engine dynamics. This investigation is based on a non-uniformly nozzles distributed passive pre-chamber, which is adjusted according to the working fluid exchange between PC and MC. The advantages and disadvantages of the ignition mode of PC and SI in the target engine speed range are compared through optical experiments on a small single cylinder GDI engine. The results show that with the increase of λ from 1.0 to 1.6, the promotion effect of PCJI on load performance gradually decreases.
An advanced multi-layer material model has been developed to simulate the complex behavior in case-carburized gears where hardness dependent strength and elastic-plastic behavior is characterized. Also, an advanced fatigue model has been calibrated to material fatigue tests over a wide range of conditions and implemented in FEMFAT software for root bending fatigue life prediction in differential gears. An FEA model of a differential is setup to simulate the rolling contact and transient stresses occurring within the differential gears. Gear root bending fatigue life is predicted using the calculated stresses and the FEMFAT fatigue model. A specialized rig test is set up and used to measure the fatigue life of the differential over a range of load conditions. Root bending fatigue life predictions are shown to correlate very well with the measured fatigue life in the rig test.
Considering that the 315 V battery may be damaged in actual use of the vehicle or the battery cannot be charged and discharged normally in a low temperature environment, this paper proposes a new "voltage control" mode and analyzes the working state of the entire vehicle under the abnormal condition of the high-voltage battery of the micro-mixing system. In order to ensure that the vehicle can still run like a traditional car under such circumstances, the paper also proposes a new "voltage control" mode. At this time, the generator is no longer in the conventional torque control mode, but in the voltage control mode. At this time, the control variable of the controller is "voltage", the working mode switching of the motor is controlled by HCU, the target voltage command is issued by HCU, the value of the target voltage can be calibrated through actual test, and the motor responds to the target voltage in real time during the system operation.
A crucial component utilized in the trunk space is the luggage board. Positioned at the bottom of the trunk, the luggage board separates the vehicle body from the interior and provides support for luggage.The luggage board serves multiple functions, including load-bearing stiffness for luggage, partition structure functionality, noise insulation, and thermal insulation. To meet the increasing demand for luggage boards in response to the changing market environment, there is a need for a competitive new luggage board manufacturing method. To address this, the "integrated sandwich molding method" is required. The integrated sandwich molding method utilizes three key methodologies: grouping processes to integrate similar functions, analyzing materials to replace them with suitable alternatives, and overcoming any lacking functionality through integrated design structures.
Side doors are pivotal components of any vehicle, not only for their aesthetic and safety aspects but also due to their direct interaction with customers. Therefore, ensuring good structural performance of side doors is crucial, especially under various loading conditions during vehicle use. Among the vital performance criteria for door design, torsional stiffness plays an important role in ensuring an adequate life cycle. This paper focuses on investigating the impact of several door structural parameters on the torsional stiffness of side doors. These parameters include the positioning of the latch, the number of hinge mounting points on doors (single or double bolt), and the design of inner panel with or without Tailor Welded Blank (TWB) construction.
The study investigates the ride comfort of a rail vehicle with semi-active suspension control and its effect on train vertical dynamics. The Harmony Search algorithm optimizes the gains of a proportional integral derivative (PID) controller using the self-adaptive global best harmony search method (SGHS) due to its effectiveness in reducing the tuning time and offering the least objective function value. Magnetorheological (MR) dampers are highly valuable semi-active devices for vibration control applications rather than active actuators in terms of reliability and implementation cost. A quarter-rail vehicle model consisting of six degrees of freedom (6-DOF) is simulated using MATLAB/Simulink software to evaluate the proposed controller's effectiveness. The simulated results show that the optimized PID significantly improves ride comfort compared to passive.
A lot of parts about 20,000 to 40,000 are composed of a car. When developing new car, design, manufacturing, cost, quality control and etc. are reviewed for these parts. In order to develop parts with low price and high quality, various factors such as design, manufacturing and cost need to optimize specifications for each part in development stage. In particular, this optimization is most effective when it is done at the design stage. A comprehensive review should be made based on various information such as design, manufacturing and cost for each component to optimize these specifications. However, the information is managed separately by each development department, so access to the information is limited. In addition, there are many inefficiencies in generating, searching, analyzing and processing the information.
Mo free 1.6GPa bolt was developed for The Variable Compression Turbo (VC-Turbo) engine, which is effective for environmental friendliness and improving fuel efficiency and output. Mo contributes not only to the improvement of temper softening resistance, but also the improvement of delayed fracture resistance by precipitating fine carbides during high-temperature tempering and effecting as trap sites for hydrogen, so the main issue is to achieve both high strength and delayed fracture resistance. Therefore, developed steel is added Si to improve tempering softening resistance and achieve a microstructure superior to delayed fracture resistance to achieve both high strength and delayed fracture resistance. The delayed fracture test was done by Hc/He method. Hc means the limit of the diffusible hydrogen contents without causing delayed fracture under tightening, and He means diffusible hydrogen contents entering under the hydrogen charging condition equivalent to actual environment.
In the process of designing the aerodynamic kit for FSAE racing cars, there is a lot of repetitive work and low efficiency in optimizing parameters such as the angle of attack, chord length, and wing gap size. The optimization of these parameters is difficult to achieve through theoretical analysis and heavily relies on simulation results and design experience. Due to the short design cycle of racing cars, it is challenging to achieve the optimal solution. By establishing a parametric model in CAD software and integrating it with CFD software, the model parameters are automatically modified, imported into the CFD software for automatic simulation, and the simulation results are automatically analyzed using statistical methods. Based on the results, the model parameters are optimized within the allowable range of rules. After multiple iterations, the parameters are fully automatically optimized, achieving a higher negative lift coefficient.
This article presents a case study that was conducted at a renowned Danish manufacturing company that desired to employ AGVs in one of their production facilities. The main goal was to create an AGV system that is well synchronized with the manufacturing facility so that intralogistics problems are avoided during manufacturing activities. AGV routing and scheduling, loading, and waiting periods, battery management, and failure management were all considered when developing the AGV logic. As a result, it was confirmed that the AGV system in place can support a production system to meet cycle time requirements. A hierarchically structured discrete event simulation model was created to examine the logic of AGVs and the interplay between AGVs and manufacturing operations. This paper also looked at a few ideas for virtual commissioning of the developed AGV System and the benefits that would follow.
The IncQuery AUTOSAR-UML Bridge is an innovative solution for Assisted Documentation Creation and Automated Handover, aiming at driving a paradigm shift in integrated digital engineering in automotive domain. The AUTOSAR-UML Bridge is addressing a well-known gap in the engineering ecosystem of automotive design, where the co-design of AUTOSAR models and other model-based artifacts is often hampered by tedious workflows involving manual syncing. The Bridge is aiming at streamlining those automotive engineering workflow by generating high-quality UML models from AUTOSAR projects, with built-in ISO26262 and ASPICE compliance. Automotive software architects and systems engineers spend a lot of time with creating ISO26262-compliant documentation, by creating UML models from AUTOSAR architecture designs, or establishing traceability between requirements captured in SysML and design artefacts that exist in both modeling languages.
With the exponential increase in the complexity of the modern automobile, especially with the advent of fully connected vehicles that are heavily focused on software, a systems engineering-centered approach to automobile development is imperative. This need is critical in legacy organizations that have thus far delivered robust and reliable vehicles based on architectures that have been optimized over decades. With the increased focus on software, it becomes necessary to approach the development of automobiles from an integrated product perspective. Such an approach should consider the co-development of both hardware and software systems within the vehicle ecosystem as opposed to separate developments in siloes that then must be integrated into the vehicle, which could lead to potential integration issues, such as churn. We believe that a function-based approach to vehicle architecting can ensure cohesive systems development and a well-integrated vehicle.