Criteria

Display:

Results

Viewing 1 to 30 of 33500
2017-11-27
Technical Paper
2017-01-5022
Sebastian Zirngibl, Stefan Held, Maximilian Prager, Georg Wachtmeister
Abstract In order to fulfill future exhaust emission regulations, the variety of subsystems of internal combustion engines is progressively investigated and optimized in detail. The present article mainly focuses on studies of the flow field and the resulting discharge coefficients of the intake and exhaust valves and ports. In particular, the valves and ports influence the required work for the gas exchange process, as well as the cylinder charge and consequently highly impact the engine’s performance. For the evaluation of discharge coefficients of a modern combustion engine, a stationary flow test bench has been set up at the Chair of Internal Combustion Engines (LVK) of the Technical University of Munich (TUM). The setup is connected to the test bench’s charge air system, allowing the adjustment and control of the system pressure, as well as the pressure difference across the particular gas exchange valve.
2017-11-15
Journal Article
2017-32-0120
Go Asai, Yusuke Watanabe, Shuntaro Ishiguro, Gen Shibata, Hideyuki Ogawa, Yoshimitsu Kobashi
To extend the operational range of premixed diesel combustion, fuel reformation by piston induced compression of rich homogeneous air-fuel mixtures was conducted in this study. Reformed gas compositions and chemical processes were first simulated with the chemistry dynamics simulation, CHEMKIN Pro, by changing the intake oxygen content, intake air temperature, and compression ratio. A single cylinder diesel engine was utilized to verify the simulation results. With the simulation and experiments, the characteristics of the reformed gas with respect to the reformer cylinder operating condition were obtained. Further, the thermal decomposition and partial oxidation reaction mechanisms of the fuel in extremely low oxygen concentrations were obtained with the characteristics of the gas production at the various reaction temperatures.
2017-11-07
Technical Paper
2017-36-0085
Julio Cesar Lelis Alves, Flavio Koiti Maruyama, Leonardo José Della Volpe, Filipe Fabian Buscariolo, Felipe Magazoni
Abstract The advances in High Performance Computing-HPC and CPU's sizes and processing power, combined with new computational codes, which are capable of coupling different types of simulation, are the main contributors for the increasing number of the Multiphysics simulations inside the industry. Multiphysics are defined as simulations involving multiple physical models or multiple simultaneous physical phenomena. Among some examples, spray modeling is of great interest in several branches of the industry and, with the development on algorithms and codes, simulations presented reliable results, compared to experiments. This work aims to contribute to both Multiphysics and spray modelling by reproducing a rainstorm condition, focused on a vehicular application. This work objective is evaluate the possibility and feasibility to reproduce virtually rain storm condition on a highway checking water intrusion at Air Intake System - AIS and compare with physical test.
2017-11-07
Technical Paper
2017-36-0087
Michele Pirola dos Santos, Kauê Cruz Silva, Diego Bellano Paulo, Carlos Alberto Barth Freitas Filho
Abstract The loss of preload in bolted joints is the main cause of quality problems, reworks or even joint failures during work. Several measurement methods are presented in the literature, but the difference of precision between each one or even the right criteria to select the most appropriate method for each project is not clearly defined. This study evaluated the differences between two of the main losses of preload measurements methods currently used in the market: clamp load through elongation measurement by ultrasonic method and checking torque method. For this, a load cell was used to measure the clamp load after the tightening torque and joint relaxation. Since the checking torque method is one of the most frequently used method of the torque auditing, it is also presented a torque x angle curve analysis for different torque points that are normally displayed by the measuring equipment.
2017-11-07
Technical Paper
2017-36-0081
Gimaezio Gomes Carvalho, Luis Guilherme Mariano Viana Martins
Abstract The business environment is ever changing, several innovations have allowed companies to transcend borderlines and become global entities. While the opportunities are numerous so are the challenges. In this fiercely competitive global marketplace, success requires companies to pay closer attention to supplier relations. The relationship between an automotive industry and its suppliers is an example of it, so the application of CAE (Computer Aided Engineering) superelement technique may improve, in terms of NVH (Noise, Vibration and Harshness), the vehicle development efficiency, without compromising confidentiality directives. Most of NVH requirements must be tracked through Transfer Functions (TFs) analyses at response points located on the Trimmed-Body Finite Element Model (FEM), as for example: Point Mobility, Vibration Transfer Function (VTF) and Acoustic Transfer Function (ATF).
2017-11-07
Technical Paper
2017-36-0150
Marco Gabaldo, Otávio Rodrigues Barros, Jose Eduardo Mautone Barros
Abstract This study analyzes the design of a two-stage reusable satellite launch vehicle. This launcher was designed to orbit payloads of up to 500 kg to low orbits (LEO). Two RISCRAM™ jet engines (Rocket Ignited Supersonic Combustion Ramjet) power the first stage that is fully reusable. They aspirate atmospheric air and allows speeds of up to Mach 6, below 30 km, and Mach 15 above 40 km of altitude. The second stage is powered by a solid rocket motor that carries the payload at the orbital speed of Mach 24. In this work are presented details of the concept of the vehicle and an economic feasibility analysis of system operation. Launch cost estimative are made and compared to the values of the current satellite launchers that are not reusable. The conclusion of the article is that the proposed system would be able to reduce by an order of magnitude the cost of placing the kilogram of payload in low orbit.
2017-11-07
Technical Paper
2017-36-0131
Leonardo Porto Carioni, Thiago Hoeltgebaum, Thiago Chierighini
Abstract Aiming to find the rotational inertias, the rolling resistance coefficient and the drag coefficient of an electric vehicle, a set of tests was developed based on the speed over time curves in two conditions: free acceleration on a ramp and free deceleration (coast-down) on a flat road. Since the main interest was in knowing the parameters and not only finding the resistance power for different speeds, as is usually the case for a coast-down test, an iterative analysis of both data sets was made. The methodology was validated by testing and analyzing road vehicles, because the values of the parameters were readily available, and by confronting the results of simulations for both types of tests. For the electric vehicle, redundancies and variations were used during testing for validation. The results for the road vehicles were within a margin of up to 10.4% from the reference values.
2017-11-07
Technical Paper
2017-36-0128
André Tognolli, Erica Machado, Fabio Batista, Paulo Mayer, Jamilton Silva, Fernando Utiyke
Abstract Through computational dynamic simulations is possible to achieve high reliability index in the development of automotive components, thus reducing the time and component cost can generate significant levels of competitiveness and quality. This work suggests the validation of a methodology for simulation, able to predict and quantify the best design of the parking brake cable that although it is flexible, has in its structure composite elements of different mechanical properties. Known difficulty of mathematically predict nonlinear relationships deformation under forces and moments effect was first established, studies based on experimental measurements serve as input parameters for simulating the dynamic behavior of the flexible cable. With the aid of motion making use of NX9 CAD software, it was prepared the dynamic movement that the leaf spring suspension system does.
2017-11-07
Technical Paper
2017-36-0126
Milton Monteverde Belli, Ricardo Daldegan
Abstract The development costs that new design requires are subject to everyday discussions and saving opportunities are mandatory. Using CAE to predict design changes can avoid excessive costs with prototypes parts, considering the high reliability those current mathematical models can provide. This paper presents the methodology used during the development of a parabolic leaf spring for the rear suspension of a commercial truck, considering mainly the parabolic profiles and stress distribution on the leaves, calculated using CAE software (ANSYS) and experimental tests to measure the actual stress on each leaf, certifying the correlation between computational calculations and real stress on the parts during bench and vehicle evaluations.
2017-11-07
Technical Paper
2017-36-0079
Israel João Cancino Junior, Roberto P Ramos, Alex Fabian Fragoso Lima, Flávio Bréglia Sales
Abstract It is common to see application of simulations to Support product development, being parts, sub-system or complete product, like a passenger vehicle. Another possible application of the simulation is to simulate assembly of parts and sub-systems. This paper captures one example of this application, where the headlamp aim adjustment done during the assembly line, is simulated to provide design changes to avoid issues during the normal production.
2017-11-07
Technical Paper
2017-36-0074
Luis Alberto Pargas Carmona
Abstract Regression analysis is perhaps one of the most widely used statistical tools in six-sigma projects. The reason for its popularity is that it provides a formal evaluation of the relationship between one dependent variable and one or more predictors. The ordinary least squares (OLS), which is a method for estimating the parameters of the linear regression model, has some numerical properties that can be easily understood by looking at them in a geometric manner. In this paper, we discuss the fundamentals of both simple and multiple regression analysis from a geometric perspective. This approach offers an intuitive understanding of some concepts that otherwise would require a background in statistical mathematics and differential calculus. One of the topics covered in this paper is multicollinearity, whose consequences are not well understood by many practitioners.
2017-11-07
Technical Paper
2017-36-0080
Edinilson Alves Costa, Rogério Nalin
Abstract Although ignored by most people not directly involved with highway and off-road commercial trucks operation the accumulation of dust and mud on cabin side can become a rather annoying issue. Besides adhering to the passengers clothes dirt contamination may also compromise driver visibility constituting a safety concern. For a truck manufacturer it can revert into quality complaints and negatively influence customers’ future buying decisions. In this context, fascia air deflectors are common devices used in truck industry to control the airflow over the cabin panels and ultimately prevent contamination deposition. This paper presents a methodology to avoid dust and mud accumulation on commercial trucks cabin doors based on the predicted airflow field by computational fluid dynamics (CFD) and a reference flow metric defined through a simple bench test.
2017-11-07
Technical Paper
2017-36-0382
Caroline Goulart Campos, André Noronha de Oliveira, Alejandro Oscar Peralta, Ricardo Teixeira da Costa Neto, Aldélio Bueno Caldeira
Abstract In this work, an inverse problem approach is employed to estimate the suspension parameters of a light vehicle based on field tests. The modeling process of a rear-wheel drive (RWD) vehicle is depicted. The model considers only the vertical dynamics of the vehicle. The experimental data were measured by sensors installed on the vehicle during specific road tests in a proving ground. The inverse problem is solved by using the Particle Swarm Optimization (PSO), minimizing the quadratic error between experimental data and numerical results of the vehicle simulation. Accuracy, computational time, efficiency and efficacy of the model were compared regarding the behavior of the performance responses of the vehicle measured on the road tests. Throughout this process, the vehicle model was validated to be used in future studies of vehicle dynamics.
2017-11-07
Technical Paper
2017-36-0398
Luiz Guilherme de Oliveira e Caldeira, Bruno Cesar Pockszevnicki, Geisiel Moreira de Assis, Daniella Fernanda dos Santos Magalhães
Abstract Aiming the decrease of manufacturing costs, the automotive industry uses Computational Aided Engineering (CAE) and prototype testing for product development. In the field of simulation CAE could be performed using FEA (finite element analysis) or CFD (Computational Fluid Dynamic), the last one is the analysis of systems involving fluid flow, heat transfer and associated phenomena such as chemical reactions by means of computer-based simulation. One of the most important components of cooling system is a water pump which is evaluated through the fluid dynamic analysis. Therefore, this work aims to analyze the fluid flow inside an automotive water pump considering a three-dimensional steady-state using CFD, but also developing a methodology to evaluate it. The parameters of the analysis and the volumetric mesh were according to the simulated results approached the experimental results.
2017-11-07
Technical Paper
2017-36-0406
Lucas F. Berto, André L. F. Ferreira, Alvaro C. Michelotti, Pedro P. Pastorelli
Abstract In current Internal Combustion Engines (ICE), efforts have been employed in reducing emissions and fuel consumption. One of the alternatives is the reduction of the idling speed of the engines. However, such strategy involves great challenges from the aspect of torsional vibrations in the Front-End Accessory Drive (FEAD) system. Because it is coupled to the largest inertia of the FEAD assembly, the alternator pulley should provide a good vibration attenuation capability. The objective of this work is to demonstrate the development of an automotive component that employs two distinct types of springs: a clutch spring and a torsion spring. These elements are required in alternator pulleys to reduce torsional vibration generated by the crankshaft fluctuation and to avoid damage or durability issue with other components of the FEAD system.
2017-11-07
Technical Paper
2017-36-0407
Pedro P. Pastorelli, Alvaro C. Michelotti, André L. F. Ferreira, Lucas F. Berto
Abstract Among the alternatives for solving NVH (Noise, Vibration and Harshness) problems in automobiles, the alternator pulley has become one of the most promising alternatives in the Frond-End Accessory Drive (FEAD) of modern engines. The rigid pulley has evolved from a simple device whose only function is torque transmission to a system with much more complex functions. At this higher level of complexity, many innovative designs have been created, such as pulleys with overrunning function and pulleys with both One-Way Clutch (OWC) and vibration dampening functions, which are devices that require a high level of study in order to guarantee an adequate design of the system for each new application. This paper presents the steps taken in dimensioning two distinct types of springs: a clutch spring and a torsion spring, to be applied in alternator pulleys with OWC and vibration dampening systems.
2017-11-07
Technical Paper
2017-36-0427
André N. Aronis, Vitor V. Cogo, Mackilini Dalla Nora, Mario E. S. Martins, Felipe V. Lewiski
Abstract Internal Combustion Engines (ICE) have their use highly disseminated in the most diverse operations. Exhaust gaseous emissions and fuel consumption have been on the scope for decades and therefore the necessity for research on more efficient and lower exhaust emission engines has increased. Considering the cost of equipment and software to develop ICE, the use of computational models is a key strategy to evaluate the behavior of the powertrain/vehicle and lower the instrumentation cost. In this sense, the present work shows the development of an algorithm to obtain a high-resolution crank angle (CA) position of an engine by means of a toothed wheel instead of a high-resolution incremental or absolute encoder. As a result, it enabled the analysis of performance and combustion parameters based on in-cylinder pressure signals acquired through a piezoelectric pressure transducer and the angular position of the crank train referenced by a Hall Effect sensor.
2017-11-07
Technical Paper
2017-36-0431
Eloy Martins de Oliveira Junior, Marcelo Lopes de Oliveira e Souza
Abstract Internet of Things (IoT) for real-time applications are demanding more and more high performance, precision, accuracy, modularity, integration, dependability and other attributes in a complex and/or highly integrated environment. Such systems need to provide coordination among the integrated components (e.g. sensors, computer, controller and networks) for enabling the application to take real-time measurements and to translate into controllable, observable and smart actions with strict timing requirements. Therefore, coordination and synchronization are required to ensure the controllable, observable and smart actions of real-time IoT systems. This paper shows the design issues about the coordination and synchronization in the internet of things applied to real-time applications. We also show the current coordination and synchronization techniques and their design issues when applied to IoT systems.
2017-11-07
Technical Paper
2017-36-0272
Victor Hugo de Castro Lima, Carlos Alberto Gomes Júnior, Márcio Expedito Guzzo, Thiago Rodrigo Vieira da Silva, José Guilherme Coelho Baeta, Fernando Antonio Rodrigues Filho
Abstract The growing demand for more efficient and less polluting engines has lead the scientific community to further develop the road map engine technologies, including direct fuel injection. Direct injection research demands the investigation of spray formation and its characteristics. The present work performs the characterization of the macroscopic parameters of ethanol sprays (E100) produced with a fuel gauge pressure of 80 bar and gauge back pressures of 0, 5 and 10 bar. The sprays analysis was performed using high speed filming by means of Shadowgraph technique. Computational routines of matrix analysis were applied to measure the spray cone angles, penetration and penetration rate. The spray visualization demanded an experimental apparatus composed of a pressurized cylinder with nitrogen, a fuel tank as pressure vessel, an injection driver equipped with a peak and hold module controlled by a MoteC M84, a Phantom V7.3 high speed camera and LEDs for illumination.
2017-11-07
Technical Paper
2017-36-0285
Gabriel Dalmolin, Euler Cássio Tavares de Macedo, Marcelo Geisler de Brito Lira, Nady Rocha
This paper presents the simulation of an electrical traction system using an Axial Flux Permanent Magnet (AFPM) motor using the MATLAB® computational environment. It was developed the analytical model of the entire traction system which consists of a voltage inverter, a AFPM motor, a Field Oriented Control (FOC) control system with a torque reference and the dynamic system of the vehicle. For the simulation, it was considered two distinct scenarios,i.e. a horizontal plane with no inclination and an inclined plane in a way to allow the complete system dynamic comparison. The variables of interest are the electromagnetic torque, the currents in the machine’s terminals and the final vehicle speed, which proved the estimated dynamics.
2017-11-07
Technical Paper
2017-36-0281
Rafael Rodrigues da Silva, Evandro Leonardo Silva Teixeira, André Murilo de Almeida Pinto, Max Mauro Dias Santos
Abstract Automotive industry is looking for new design and product development practices to become more competitive. Challenges in current global market have often included sustainable development, environmental regulation and innovative solution to reach customer needs. Today, carmakers are striving to take competitive advantages over global marketplace. Model-Based-Design (MBD) seems to be a feasible answer to improve software development practices in automotive industry. Furthermore, it has been reported as a novel development approach to develop advanced driver assistance systems (ADAS). Among ADAS technologies often required to reduce driver fatigue is Electric Power Assisted Steering (EPAS). By using an auxiliary servomotor, it can reduce significantly driver effort in parking maneuvers. In this scenario, this paper aims to describe how MBD can be used to design EPAS control system.
2017-11-07
Technical Paper
2017-36-0286
Juliana Lopes, Rafael Vieira, Cleber Marques, Genildo Vasconcelos, Fabrício Ferreira, Tainã Silva
Abstract The amount of fuel present in the vehicle fuel tank is an extremely important information for car users. In the majority of modern cars, the fuel level is identified through a resistance value measured by a potentiometer inside the tank. This measurement is converted to a digital information that will be filtered by computational algorithms embedded on the responsible Electronic Control Unit (ECU) and shown to the user by Instrument Panel Cluster (IPC) Gauge. The reliability of this information is a critical factor due to fuel economy and safety issues. Some agents can affect the fuel level measurement during the refueling process, such as the fuel slosh (fluid disturbance on the tank), that could compromise the reliability of the information provided to the user. Perform this feature test could be very expensive, demanding car prototypes, several engineer work hours and fuel manipulation.
2017-11-07
Technical Paper
2017-36-0309
Juliano Mologni, Jefferson Ribas, Cesareo Siqueira
Abstract In Brazil there is a significant number of medium and high voltage power cables falling on vehicles causing catastrophic accidents leading to serious injuries and deceases. It is advised that the car works as a shield so passengers inside the vehicle should not open doors and windows, but to the knowledge of the authors no work has presented a quantified study showing details like electromagnetic field intensity and 3D plots to really illustrate this situation. This work uses numerical simulation to replicate a scenario of a high power cable in direct contact with a vehicle and numerous positions of human body models inside and outside of the vehicle. Electromagnetic field is calculated showing the shielding effectiveness of the vehicle chassis. Also, current density are calculated to show the path of the current including the human body models. Safety guidelines are presented based on electromagnetic field strength and several scenarios are simulated and quantified.
2017-11-07
Technical Paper
2017-36-0319
Antonio Carlos Scardini Villela, Rogério Nascimento de Carvalho
Abstract Currently, fuels development is strongly dependent on experiments. New engines and vehicles simulation methodologies contribute to speed up R & D projects deadlines, as well as reducing costs. This paper presents a modeling methodology for a vehicle deceleration load curve (coast down) prediction and simulations of coast down variations impact on urban and highway autonomies. Two coast down curve mathematical models were successfully developed and validated. The first one, based on vehicles technical specifications and empirical equations, resulted in percent differences up to 9% compared to the experimental results. This is lower than the variation established on coast down standard, which is 15%. The second, generated by regression analysis between other vehicles characteristics versus experimental results of F0 and F2 (coast down curve parameters), resulted in percent differences up to 15%, for six of the eight vehicles.
2017-11-07
Technical Paper
2017-36-0335
Fábio de Castro Radicchi, Leonardo Mayer Reis, Bruno Vieira Silva, Ramon Molina Valle, Erwin Karl Franieck, Paulo César de Ferreira Gomes, Gustavo Santos Lopes
Abstract The analysis of the air motion inside the cylinders of an internal combustion engine constitutes a very important step during engines design. It is already known that its movement, normally decomposed in tumble and swirl motion, is totally related to the majority of phenomena which occur inside cylinder, like fuel evaporation, mixture formation or flame propagation. The use of mechanical devices in the intake system represents an interesting option in the attempt of optimizing the airflow and finding the best condition for maximum power and minimum specific fuel consumption. Devices like flow boxes, which control the airflow and change its main characteristics before entering the cylinder, by obstructing the air and changing its directions, are one possibility. Based on this idea, this paper presents a numerical analysis of the utilization of a flow box in the intake system of a spark ignition engine.
2017-11-07
Technical Paper
2017-36-0346
Bruno Silva de Lima, Alysson Fernandes Teixeira, Arthur Braga Thiriet, Ramon Molina Valle
Abstract This paper describes a reverse engineering methodology to obtain a three-dimensional (3D) model of an internal geometry of an engine adapted with a torch ignition system. The reverse engineering methodology began with the measurement of the internal geometry from the cylinder head using silicon. Then, the obtained silicone molds were analyzed in a 3D scanner obtaining a cloud of points which was then treated in a commercial CAD software in order to generate de 3D computer model. The virtual geometry obtained was used to run CFD simulations with the torch ignition system. In order to increase the reliability of the results, a comparison between the pressures in the cylinder obtained numerically and experimentally were made. The same procedure was made in the pre-chamber, thus validating the model.
2017-11-07
Technical Paper
2017-36-0348
Rafael Kiemo Pfau Santos, Marcus Vinicius Hamann Silveira, Modesto Hurtado Ferrer
Abstract Considering technology development and the raise in computational power, numerical methods became important device in developing new products and in improving existing ones, being a differential for market competition among companies, consequently from the reduction of time and cost in projects. For Student Competition Teams, like Formula and Mini Baja SAE series, the use of simulation is even more important in their vehicle development, due to team limited resources available and their lack of experience. This work has the main goal of presenting the development steps of a structural component of the suspension system, the steering knuckle, for Formula SAE competition vehicles, aided by computational aided engineering. Starting from the geometrical and functional configuration of the vehicle, a multibody model was generated by the Altair Motion View software to simulate high performance maneuvers, and then estimate two cases of loads.
2017-11-07
Technical Paper
2017-36-0434
Leonam S. D. Pecly, Marcelo L. O. e Souza, Keyvan Hashtrudi-Zaad
Abstract System dynamics identification has an important role in engineering, whether it is for used for modeling dynamic objects or mechanisms, controller design, or simulation of dynamic systems. The accuracy of estimation certainly depends on how the input variables used for estimation are obtained and synchronized in time. For systems such as actuators where usually only position is measured, the velocity and acceleration input variables are obtained in discrete-time domain through difference equations that shift the signals in time. In this way, the incorrect data synchronization in time might become an issue; likewise in online identification where filters used might cause significant phase delay. In this paper, the effect of discrete data synchronization for offline and online identification of dynamic systems is studied.
2017-11-07
Technical Paper
2017-36-0441
Diego David Silva Diniz, Carlos Costa De Carvalho, Antônio Almeida da Silva
Abstract In the last decades, the improvement of the automotive industry and the raising market exigence have stimulated studies in vehicle dynamics. That studies force the companies to focus their efforts in producing new conceptions and optimizing the existing ones, being able to obtain faster, safer, and more comfortable vehicles. The evolution of computing has made the task of making numerical simulations for complex models of vehicles. This allow the engineers to reproduce the real dynamic behavior of the vehicle submitted to a wide range of scenarios. Therefore, this study aims to use the multibody method to model and simulate, through computers, the vertical dynamic behavior of an off-road vehicle (baja) with a Double Wishbone suspension in both front and rear.
2017-11-07
Technical Paper
2017-36-0167
Alvaro Cesar Garcia, Cleber William Gomes
Abstract The turbocharger has unleashed a new era of highly efficient internal combustion engines and shows the right technology to meet global emissions laws. With a simple concept, the turbocharger can reduce the specific fuel consumption, increase engine power and torque by increasing its volumetric efficiency. By using the energy contained in the exhaust gases, the turbocharger compresses the atmospheric air, increasing its density, so that at the moment of combustion there is a more efficient burning of the fuel injected. The purpose of this paper is to analyze the internal components of the turbocharger and a computer simulation made in Ricardo Software's Waves to analyze differences in fuel consumption, volumetric efficiency, torque and in the power of a turbocharged engine compared to the same engine, but without the turbocharger installed.
Viewing 1 to 30 of 33500