Criteria

Display:

Results

Viewing 1 to 30 of 31020
2016-05-05
Journal Article
2015-01-9148
Saeed Asgari, Shailendra Kaushik
Abstract A linear parameter varying (LPV) reduced order model (ROM) is used to approximate the volume-averaged temperature of battery cells in one of the modules of the battery pack with varying mass flow rate of cooling fluid using uniform heat source as inputs. The ROM runs orders of magnitude faster than the original CFD model. To reduce the time it takes to generate training data, used in building LPV ROM, a divide-and-conquer approach is introduced. This is done by dividing the battery module into a series of mid-cell and end-cell units. A mid-cell unit is composed of a cooling channel sandwiched in between two half -cells. A half-cell has half as much heat capacity as a full-cell. An end-cell unit is composed of a cooling channel sandwiched in between full-cell and a half-cell. A mass flow rate distribution look-up-table is generated from a set of steady-state simulations obtained by running the full CFD model at different inlet manifold mass flow rate samples.
2016-04-15
Journal Article
2015-01-9020
Emre Sert, Pinar Boyraz
Abstract Studies have shown that the number of road accidents caused by rollover both in Europe and in Turkey is increasing [1]. Therefore, rollover related accidents became the new target of the studies in the field of vehicle dynamics research aiming for both active and passive safety systems. This paper presents a method for optimizing the rear suspension geometry using design of experiment and multibody simulation in order to reduce the risk of rollover. One of the major differences of this study from previous work is that it includes statistical Taguchi method in order to increase the safety margin. Other difference of this study from literature is that it includes all design tools such as model validation, optimization and full vehicle handling and ride comfort tests. Rollover angle of the vehicle was selected as the cost function in the optimization algorithm that also contains roll stiffness and height of the roll center.
2016-04-05
Journal Article
2015-01-9153
André Lundkvist, Arne Nykänen
Abstract The number of advanced driver assistance systems is constantly increasing. Many of the systems require visual attention, and a way to reduce risks associated with inattention could be to use multisensory signals. A driver's main attention is in front of the car, but inattention to surrounding areas beside and behind the car can be a risk. Therefore, there is a need for driver assistance systems capable of directing attention to the sides. In a simulator study, combined visual, auditory and vibrotactile signals for directional attention capture were designed for use in driver assistance systems, such as blind spot information, parking assistance, collision warnings, navigation, lane departure warning etc. An experiment was conducted in order to measure the effects of the use of different sensory modalities on directional attention (left/right) in driver assistance systems.
2016-04-05
Technical Paper
2016-01-0632
Domenico Crescenzo, Viktor Olsson, Javier Arco Sola, Hongwen Wu, Andreas Cronhjort, Eric Lycke, Oskar Leufven, Ola Stenlaas
Due to demanding legislation on exhaust emissions for internal combustion engines and increasing fuel prices, automotive manufacturers have focused their efforts on optimizing turbocharging systems. Turbocharger system control optimization is difficult: Unsteady flow conditions combined with not very accurate compressor maps make the real time turbocharger rotational speed one of the most important quantities in the optimization process. This work presents a methodology designed to obtain the turbocharger rotational speed via vibration analysis. Standard knock sensors have been employed in order to achieve a robust and accurate, yet still a low-cost solution capable of being mounted on-board. Results show that the developed method gives an estimation of the turbocharger rotational speed, with errors and accuracy acceptable for the proposed application. The method has been evaluated on a heavy duty diesel engine.
2016-04-05
Technical Paper
2016-01-0054
Eduard Lyubimov, Sergey Gladyshev, Dmitriy Istselemov, Nikolay Belyaev
The synchronous electrical machines are used in regular cars, electrical, and hybrid cars as generators or motors. They need to be tested after fabrication and also during maintenance. For this purpose can be used suggested measurement complex. The software structure of the considered measurement complex was defined according: Russian, IEC, and IEEE standards for testing synchronous machines. The software of measurement complex was designed by using Lab VIEW development modules and is orientated to work with National Instruments hardware. It consist of nine interconnected Virtual Instruments (VIs) to carry out: the no-load test, the sustained short-circuit test, the V-curve test, the load angle test, to plot Potier diagram, the sudden short circuit test, to acquire the transient response characteristic and determine optimal PID controller parameters, to generate test report, to control the testing process.
2016-04-05
Technical Paper
2016-01-0267
Rahul Rama Swamy Yarlagadda, Efstratios Nikolaidis, Vijay Kumar Devabhaktuni
Over the last two decades inverse problems have become increasingly popular due to their widespread applications. This popularity continuously demands designers to find alternative methods, to solve the inverse problems, which are efficient and accurate. It is important to use effective techniques that are both highly accurate and computationally efficient. This paper presents a method for solving inverse problems through Artificial Neural Network (ANN) theory. This paper also presents a method to apply Grey Wolf optimizer (GWO) algorithm to solve inverse problems. GWO is a recent optimization method demonstrating great results. Both of the methods are then compared to traditional methods such as Particle Swarm Optimization (PSO) and Markov Chain Monte Carlo (MCMC). Four typical engineering design problems are used to compare the four methods' performance. The results show that the GWO outperforms other methods both in terms of efficiency and accuracy.
2016-04-05
Technical Paper
2016-01-0397
Wenxin Qin, Sandip Datta, Weidong Zhang
In automotive chassis, body and powertrain finite element numerical analysis, more and more analysts and engineers like to adopt 3D complex FEA models along with improved computer hardware and software. The advantages of 3D FEA model are (1) looked like real model in vision; (2) simulation response is more vivid; (3) easily to discover the mistakes by watching simulation response. The drawbacks of 3D FEA model are (1) more pre/post process works and computation time; (2) numerical divergence is a challenging issue in nonlinear and contact situations and debug becomes difficulty; (3) sometimes accumulated numerical errors will cover the actual response. Therefore, it is necessary to explore what kinds of 3D FEA situations can be successfully converted by the simple 2D plan FEA models.
2016-04-05
Technical Paper
2016-01-0395
Anindya Deb, Clifford C. Chou, Gunti R. Srinivas, Sanketh Gowda, Goutham kurnool
An attractive strategy for joining non-ferrous or non-metallic substrates is through adhesive bonding. This technique of joining also offers the functionality for joining dissimilar materials. However, doubts are often expressed on the ability of such joints to perform on par with other mechanical fastening methodologies such as welding, riveting, etc. In the current study, adhesively-bonded single lap shear (SLS) and double lap shear (DLS) joints are studied initially under quasi-static (at a cross-head speed of 1 mm/min) tensile and flexural loading using steel and aluminum substrates, and an epoxy-based adhesive of a renowned make. The study includes usage of similar substrates made of only steel or aluminum, or a combination of steel and aluminum substrates. Load-displacements curves for bonded joints are presented for varying overlap lengths.
2016-04-05
Technical Paper
2016-01-0552
Hui Liu, Zhi Wang, Yan Long, Yunliang Qi, Dongbo Yang, Jianxin Wang
A 1D model of fluid dynamic and chemistry kinetics following hot spot auto-ignition has been developed to simulate the process from auto-ignition to pressure wave propagation. The role of wall effect on the physical–chemical interaction process is numerically studied. A pressure wave is generated after hot spot auto-ignition and gradually damped as it propagates. The reflection of the wall forms a reflected pressure wave with twice the amplitude of the incident wave near the wall. The superposition of the reflected and forward pressure waves reinforces the intensity of the initial pressure wave. Wall effect is determined by the distance between the hot spot center and the cylinder wall. Hot spot auto-ignition near the wall easily initiates detonation under high-temperature and high-pressure conditions because pressure wave reflection couples with chemical reactions and propagates in the mixture with high reactivity.
2016-04-05
Technical Paper
2016-01-0584
Vesselin Krassimirov Krastev, Gino Bella
Turbulence modeling is a key aspect for the accurate simulation of ICE related fluid flow phenomena. RANS-based turbulence closures are still the preferred modeling framework among industrial users, mainly because they are robust, not much demanding in terms of computational resources and capable to extract ensemble-averaged information on a complete engine cycle without the need for multiple cycles simulation. On the other hand, LES-like approaches are gaining popularity in recent years due to their inherent scale-resolving nature, which allows the detailed modeling of unsteady flow features such as cycle-to-cycle variations in a DI engine. An LES requires however multiple simulated engine cycles to extract reliable flow statistics, which coupled to the higher spatial and temporal resolution compared to RANS still poses some limits to a wider application of such methodology on realistic engine geometries.
2016-04-05
Technical Paper
2016-01-1338
Weight reduction is very important in automotive design because of stringent demand on fuel economy. Structural optimization of dynamic systems using finite element (FE) analysis plays an important role in reducing weight while simultaneously delivering a product that meets all functional requirements for durability, crash and NVH. With advancing computer technology, the demand for solving large FE models has grown. Optimization is however costly due to repeated full-order analyses. Reanalysis methods can be used in structural vibrations to reduce the analysis cost from repeated eigenvalue analyses for both deterministic and probabilistic problems. Several reanalysis techniques have been introduced over the years including Parametric Reduced Order Modeling (PROM), Combined Approximations (CA) and the Epsilon algorithm, among others.
2016-04-05
Technical Paper
2016-01-1389
Travis Carrigan, Mark Landon, Claudio Pita
High quality mesh generation technology coupled with a robust shape deformation technique enables large design space exploration for optimization without the need to remesh the geometry. To demonstrate this, we present a collection of best practices for cleaning complex analytic CAD data that together with a robust grid generation algorithm enable the automatic generation of high quality boundary layer resolved grids that retain their quality when morphed during the optimization process. The case study for this work is the DrivAer model developed by the Institute of Aerodynamics and Fluid Mechanics at the Technische Universität München. The first step in the proposed automated optimization framework is to use a technique called Solid Meshing to heal faults in the provided geometry and recover its original engineering intent.
2016-04-05
Technical Paper
2016-01-0030
Jungkyum Yu, Geesu Lee, Hyunsung Lee, Jaepoong Lee, Kwangil Kim, Youngsuk Kim, Sangkyong Lee, Sangwoo Jeon, Kyongsu Yi
As an effective approach for the design, implementation and testing of control systems, hardware-in-the-loop (HIL) testing has been used in many research areas. This paper describes a real-time HIL simulation test for the automotive electronic control system. The HIL system proposed in this paper consists of three parts: real-time target hardware, electronic control unit (ECU) of automotive electronic control systems and signal-conditioning unit which regulates the voltage levels between real-time target and ECU. The HIL simulation evaluates the mechanical and electronic behaviors in real time using off-line simulation models by interfacing real-target with electrical control units via interface box. The model was developed by MATLAB/Simulink. The model is composed of mechanical part which predicts dynamic behaviors and electronic part to calculate the motor speeds, current and electronic loads under the various conditions.
2016-04-05
Technical Paper
2016-01-1329
Fulin Wei, Yanhua Shen, Tao xu
Abstract: The wear degree of body which is one of major parts of off- road dump truck has direct influence on maintenance and replacement during its service process. In this paper the discrete element method is used to simulate the dumping work for one 110t dump truck body, and the wear variation curve at one point of body floor is achieved in terms of Archard wear theory during one dumping process. Assuming that the variation of body wear is consistent with geometric Brown movement, the mathematical model of body wear is built based on the stochastic differential theory. The two parameters in the stochastic differential equation, drift coefficient and diffusion coefficient, can be evaluated by the wear variation curve. It is possible to quantitatively predict the wear evolution at any position of the body floor. The wear trend of mathematical model shows the same trend with the first two periods (running-in and mild wear) of general mechanical wear process.
2016-04-05
Technical Paper
2016-01-1391
Subash Sudalaimuthu, Mohamed Sithik, Roberto Pesce Jr, Chandra Mouli SANKARAN
In recent trend, there is a huge demand for lightweight components, which improves fuel efficiency and reduces cost of the vehicle. Stiffness based optimization process is simple and straightforward while durability (Misuse load case) based optimizations are relatively complex due to its highly nonlinear behaviour. However, NVH and durability performances are critical in front cradle design. So a process needs to be identified for creating a new front cradle design. This study talks about the process of identifying new cast aluminium cradle achieving NVH and durability performance. Load path study using topology optimization is done based on compliance method for the durability load case. A concept model is generated from the topology results. This concept model is optimized for thickness of ribs and walls by the application of various shape variables. Isight is used as optimizer where all the non linear durability load cases are linked using Abaqus for the shape optimization study.
2016-04-05
Technical Paper
2016-01-1396
Kai Liu, ZongYing Xu, Duane Detwiler, Andres Tovar
The objective of this investigation is to develop a design and optimization methodology for crashworthy components subject to high-strain impact load using cellular materials. Researchers have done multiple studies on design optimization of crashworthy components, design optimization of foam-filled tube and design materials with crashworthiness criteria; however, studies on design crashworthy structures using cellular materials are very limited. Our research group has proposed a systematic approach to design and optimize compliant, plastically deformable structures. This approach has proven effective on thin-wall tubular structures subject to front impact. However, the requirement for design structures subject to side impact is differences. In this investigation, our proposed three stage design optimization method is reconsidered for side impact. The first stage is to generate a good conceptual design using topology optimization.
2016-04-05
Technical Paper
2016-01-0033
Tao Wang, Sumin Zhang, Weiwen Deng
The Global Positioning System (GPS) has gained increasing popularity in recent years, as it is widely used in navigation, mapping, radar motion compensation and other related fields due to the high accuracy of 3D positioning and speed information for all kinds of users. As for the field of intelligent vehicle, the measurement accuracy and error model of GPS are needed to be known in order to ensure the credible results in the virtual simulation environment for Advanced Driver Assistance System (ADAS) and active safety technologies. Thus, it is important to establish the correct GPS observation error model when applicable. The simulation of GPS observed values and GPS positioning are both interrelated and different, for GPS positioning is used to determine the 3D position of the observed GPS signal in a certain position, and the simulation of GPS observed values attempts to restore the GPS signal which can be observed by using the 3D position that is already known.
2016-04-05
Technical Paper
2016-01-0555
Federico Millo, Sabino Caputo, Claudio Cubito, Antonella Calamiello, Davide Mercuri, Marcello Rimondi
The target for future cooling systems is to control the fluid temperatures and flows through a demand oriented control of the engine cooling to minimize energy demand and to achieve comfort, emissions, or service life advantages. The scope of this work is to create a complete engine thermal model (including both cooling and lubrication circuits) able to reproduce e engine warm up along the New European Driving Cycle in order to assess the impact of different thermal management concepts on fuel consumption. The engine cylinder structure was modeled through a finite element representation of cylinder liner, piston and head in order to simulate the cylinder heat exchange to coolant or oil flow circuits and to predict heat distribution during transient conditions. Heat exchanges with other components (EGR cooler, turbo cooler, oil cooler) were also taken into account.
2016-04-05
Technical Paper
2016-01-1397
Charles Yuan, Erik Kane, Abid Rahman
New seal cross section development is very tedious and time consuming process if conventional analysis method is used. On top of it, it is very hard to predict the right dimension of all small features in the cross-section while meeting the sealing targets. In this study, a generic seal cross section is defined and different design constraints are given. The design optimization tool Isight is used to run the analysis in iterative loop and come up with a cross-section that meets all the design requirements. The process is simple and a new section can be obtained in a day.
2016-04-05
Technical Paper
2016-01-0310
John R. Wagner, Xinran Tao
The pursuit of greater fuel economy in internal combustion engines requires the optimization of all subsystems including thermal management. The reduction of cooling power required by the electromechanical coolant pump, radiator fan(s), and thermal valve demands real time control strategies. To maintain the engine temperature within prescribed limits for different operating conditions, a continual estimation of the heat removal needs and synergistic operation of the cooling system components must be accomplished. Reduced thermal management power consumption can be achieved by avoiding unnecessary overcooling efforts which are often accommodated by extreme thermostat valve positions. In this paper, an optimized nonlinear controller for a military MATV engine cooling system will be presented. The prescribed engine coolant temperature will be tracked while minimizing the pump, fan(s), and valve power usage.
2016-04-05
Technical Paper
2016-01-1350
Alok Phulpagar, Neelam Gohel
Air intake system and filter play major role in getting good quality air into automobile engine. It improves the combustion efficiency and also reduces air pollution. The air filters in an air intake system permanently removes foreign particles such as dust, dirt and soot from the intake air, thereby maintaining the performance of the engine and protecting it from damage. Proper maintenance can help vehicles perform as designed; thereby positively affecting fuel economy, emissions, and overall drivability. Computational Fluid Dynamics (CFD) is considered to be the most cost effective solution for flow analysis of intake system along with filter media. This paper focuses on computational fluid analysis of an intake system in automobile industry to predict the pressure drop. 3D viscous CFD analysis was carried out for an existing model to understand the flow behavior through the intake system, air filter geometry and filter media using ANSYS Software.
2016-04-05
Technical Paper
2016-01-0437
Bin Tang
In order to ensure that coach drivers have good manipulation and road feeling at different speeds, variable assist characteristic of electronically controlled hydraulic power steering system (ECHPS) in a coach was designed based on drivers’ preferred steering torque. Two degrees of freedom vehicle model, steering system model and model of steering resistance moment were established for following simulation. The design method of assist characteristic was proposed. Feature points of assist characteristic curves were calculated via coach drivers’ preferred steering torque and steering resistance moment at different speeds by means of simulation. For realization of the variable assist characteristic, the optimization model of rotary valve parameters was put forward, with the minimum of quadratic sum of the difference between assisted oil pressure under characteristic speed and characterized assisted oil pressure defined as objective function.
2016-04-05
Technical Paper
2016-01-0802
Chenaniah Langness, Christopher Depcik
The use of Compressed Natural Gas (CNG) has demonstrated the potential to decrease Particulate Matter and nitrogen oxide (NOx) emissions simultaneously when used in a dual-fuel application with diesel fuel functioning as the ignition source. However, some authors do find that NOx emissions can increase. One postulation is that the conflicting results in the literature may be due to the difference in composition of natural gas around the world. Therefore, in order to investigate if CNG composition influences combustion performance and emissions, four unique mixtures of CNG were tested (i.e., 87% to 96% methane) while minimizing the combined difference of the density, heating value, and constant pressure specific heat of each mixture. This was accomplished at moderate energy substitution ratios (up to 40%) in a single cylinder engine operating at various loads.
2016-04-05
Technical Paper
2016-01-0329
Piyush Bubna, Michael P. Humbert, Marc Wiseman, Enrico Manes
Conventional car manufacturing is extremely capital and energy-intensive. Due to these limitations, major auto manufacturers produce very similar, if not virtually identical, vehicles at very large volumes. This limits potential customization for different users and acts as a barrier to entry for new companies or production techniques. Better understanding of the barriers for low volume production and possible solutions with innovative production techniques is crucial for making low volume vehicles viable and accelerating the adoption of new production techniques and lightweight materials into the competitive marketplace. Additive manufacturing brings benefits of innovative design with minimal capital investment in tooling and hence should be ideal for low and perhaps high volume parts. However the technique is currently process intensive, uses relatively expensive raw materials and has to prove the capability to produce parts of acceptable quality.
2016-04-05
Technical Paper
2016-01-1339
Piyush Bubna, Marc Wiseman
OEMs are investigating opportunities to reduce vehicle mass, driven by a need to meet upcoming CAFE targets and increase the range/reduce battery size of EVs. A number of lightweight materials including high strength steels, aluminum alloys, plastics and composites are now in production. To facilitate development of corporate R&D and commercialization plans for new materials, it is beneficial to understand the current manufacturing costs for production components, and their impact on piece price at different volumes. This paper investigates design and cost impact of light-weighting with respect to front door and floor assembly of Toyota Corolla and BMW i3. Toyota Corolla is a typical high production volume vehicle made of steel body while BMW i3 has relatively low annual sales and is primarily made of composite, aluminum and plastic parts. Use of light-weight materials in automotive have been widely researched.
2016-04-05
Technical Paper
2016-01-0585
Muhsin M. Ameen, Yuanjiang Pei, Sibendu Som
The primary strength of large eddy simulation (LES) is in directly resolving the instantaneous large-scale flow features which can then be used to study critical flame properties such as ignition, extinction, flame propagation and lift-off. However, validation of the LES results with experimental or direct numerical simulation (DNS) datasets requires the determination of statistically-averaged quantities. This is typically done by performing multiple realizations of LES and performing a statistical averaging among this sample. In this study, LES of n-dodecane spray flame is performed using a detailed combustion model along with a dynamic structure subgrid model. A high-resolution mesh is employed with a cell size of 0.0625 mm in the entire spray and combustion regions. In the first part of this study, two methods of perturbing the LES solutions is examined. The first method consists of changing a random seed which is used in the spray breakup and vaporization models.
2016-04-05
Technical Paper
2016-01-0547
Andrea Piano, Federico Millo, Giulio Boccardo, Mahsa Rafigh, Alessandro Gallone, Marcello Rimondi
The predictive capabilities of an innovative multizone combustion model, the DIPulse developed by Gamma Technologies, were assessed in this work for a last generation common rail diesel engine. A detailed validation process, based on an extensive experimental data set, was carried out concerning the predicted heat release rate, the in-cylinder pressure trace, as well as NOx and soot emissions for several engine operating points. After a preliminary calibration of the model, the combustion model parameters were then optimized through a Latin Hypercube Design of Experiment (DoE), with the aim of minimizing the RMS error between the predicted and experimental burn rate of several engine operating points, thus achieving a more than satisfactory agreement between simulation and experimental engine combustion parameters
2016-04-05
Technical Paper
2016-01-0629
Mohammad Reza Amini, Mahdi Shahbakhti, J. Karl Hedrick
Verification and validation (V&V) are essential stages in the design cycle of industrial controllers to remove the gap between the designed and implemented controller. In this study, a model-based adaptive methodology is proposed to enable easily verifiable controller design based on the formulation of a sliding mode controller (SMC). The proposed adaptive SMC improves the controller robustness against major implementation imprecisions including sampling and quantization. The application of the proposed technique is demonstrated on the engine cold start emission control problem in a midsize passenger car. The cold start controller is first designed in a single-input single-output (SISO) structure with three separate sliding surfaces, and then, is redesigned based on a multi-input multi-output (MIMO) SMC design technique using nonlinear balanced realization.
2016-04-05
Technical Paper
2016-01-1330
Lei Shi, Peng Yi, Zhan Zhang
The body joint stiffness plays an important role in achieving vehicle attribute targets. One of the major drawbacks of joint stiffness evaluation is the lack of a rigorous criterion to assess whether the stiffness is proper for a body structure. This paper presents a general metric based on Hooke's low to better evaluate the stiffness of a body joint. A strategy for target setting of body joint stiffness was developed for vehicle body design. Finally, a vehicle body example was presented to demonstrate the proposed methodology.
2016-04-05
Technical Paper
2016-01-1646
Tao xu, Yanhua Shen, Wenming Zhang
The traditional hydraulic steering mode in articulated motor-driven vehicle is liable to make the vehicle’s structure more complex and damage the joint body when steering. Thus the skid-steering mode could be implemented to replace the hydraulic steering mode in articulated vehicle, which is without steering cylinder but more flexible by controlling the velocity of each wheel when steering. This paper will introduce the skid-steering principle and establish the in-situ skid-steering dynamic model of articulated motor-driven vehicle according to the theory of traditional wheeled vehicle’s skid-steering and dynamic analysis of hydraulic steering of articulated vehicle. Based on the model, the vehicle trajectory and dynamic relationships among the body structure, longitudinal forces and lateral forces between each tire and the ground will be described.
Viewing 1 to 30 of 31020