Refine Your Search

Topic

Author

Affiliation

Search Results

Journal Article

Parameter Optimization of a Turbo Charged Direct Injection Flex Fuel SI Engine

2009-04-20
2009-01-0238
With the increased interest in the use of ethanol as an alternative fuel to gasoline, Original Equipment Manufacturers (OEMs) have responded by adapting their current range of vehicles to be able to run on gasoline/ethanol blends. Flex fuel vehicles are defined are defined as those that are capable of running gasoline up to 100% ethanol. Other than changes to materials compatibility, to enable the required durability targets to be met when running on ethanol, very little in the way of changes are performed to take advantage of the properties of ethanol. Calibration changes are typically limited to changes in fueling requirements and ignition timing. The physical and chemical properties of ethanol/gasoline blends offer a mixture of advantages and disadvantages. Lower energy density in the form of lower heating value reduces vehicle range whilst higher octane ratings make these excellent fuels for boosted operation.
Technical Paper

Gear Whine Modulation Root Cause Analysis and Elimination

2007-05-15
2007-01-2235
As engines and powertrains become quieter, sound quality becomes more important as an indicator of product quality. As a consequence, there is a heightened need to reduce gear noise. The objective of this work was to identify the source and cause of a modulated gear whine. The approach taken to identify the source of the modulation involved running a full powertrain on a spin stand and minimizing the number of meshing gear pairs until the offending pairs were identified. Further experimental testing and analysis models were employed to determine the cause of the modulation. From proximity probe measurements and backed up by the analytical model, it was determined that one of the gear mesh suffered from inadequate bearing support and off-center gear loads. This condition caused a tilt in one of the meshing gears which created a sideband that modulated with the primary meshing frequency of the transfer gear at cruise speed.
Technical Paper

Cylinder Head Gasket Simulation in Finite Element Analysis

1998-02-23
980843
This paper discusses a new approach to the finite element analysis of cylinder head gaskets. The new method is based on a feature of the ABAQUS® finite element solver which allows the user complete freedom to define unique material properties. This is an attractive option for cylinder head gasket analysis because the user has the freedom to describe materials which are non-linear and anisotropic. There is also the possibility of specifying independent loading and unloading characteristics. To ensure repeatability and avoid errors, the new method includes a user-friendly program to automate the input deck preparation procedure. In addition to offering new capabilities, the new method was found to converge more quickly than the current gasket analysis method.
Technical Paper

Ceramic Tappets Cast in Aluminum Alloy for Diesel Engines

1990-02-01
900403
The authors developed, for use in diesel engines, ceramic tappets cast in aluminum alloy that drastically improved wear resistance and valve train dynamics. The ceramic tappets consist of two parts: a ceramic head, which contacts the cam and push rod, and a tappet body made of aluminum alloy. Concerning the ceramic, silicon nitride was the best material of the three ceramics evaluated in the tests and the sliding surface, in contact with the cam and push rod, was left unground. As for the aluminum alloy, hyper-eutectic aluminum-silicon alloy with a controlled pro-eutectic silicon size was selected. A reliability analysis using the finite-element method (FEM) was also made on the structure of the ceramic tappet for enhanced durability and reliability. The combination of this tappet and a cam made of hardened ductile cast iron, hardened steel, or chilled cast iron, respectively exhibits excellent wear resistance.
Technical Paper

Impact Dependent Properties of Advanced and Ultra High Strength Steels

2007-04-16
2007-01-0342
The automotive industry is pursuing significant cost competitive efforts to reduce vehicle weight while maintaining or improving durability and impact performance. One such effort for the body shell structure is the utilization of advanced and ultra high strength steels (AHSS and UHSS) using the existing automotive manufacturing infrastructure. Common AHSS and UHSS steels include Dual Phase (DP), Transformation Induced Plasticity (TRIP), Partial Martensitic (PM) and others. The use of these multiphase high strength steels for impact dependent components has resulted in the need for further material characterization in order to better predict impact performance and guide new material development. This paper addresses the material properties and microstructural influences on impact behavior of advanced and ultra high strength steels through the use of laboratory tests and component level testing.
Technical Paper

Robust Compressor Model for AC System Simulation

2007-04-16
2007-01-0596
Simple component models are advantageous when simulating vehicle AC systems so that overall model complexity and computation time can be minimized. These models must be robust enough to avoid instability in the iteration method used for determining the AC system operating or “balance” point. Simplicity and stability are especially important when the AC system model is coupled with a vehicle interior model for studies of transient performance because these are more computationally intensive. This paper presents a semi-empirical modeling method for compressors based on dimensionless parameters. Application to some sample compressor data is illustrated. The model equations are simple to employ and will not introduce significant stability problems when used as part of a system simulation.
Technical Paper

The Effects of Hydroforming on the Mechanical Properties and Crush Behaviors of Aluminum Tubes

2007-04-16
2007-01-0986
The effect of hydroforming on the mechanical properties and dynamic crush behaviors of tapered aluminum 6063-T4 tubes with octagonal cross section are investigated by experiments. First, the thickness profile of the hydroformed tube is measured by non-destructive examination technique using ultrasonic thickness gauge. The effect of hydroforming on the mechanical properties of the tube is investigated by quasi-static tensile tests of specimens prepared from different regions of the tube based on the thickness profile. The effect of hydroforming on the dynamic crush behaviors of the tube is investigated by axial crush tests under dynamic loads. Specimens and tubes are tested in two different heat treatment conditions: hydroformed-T4 (as-received) and T6. The results of the quasi-static tensile tests for the specimens in hydroformed-T4 condition show different amounts of work hardening depending on the regions, which the specimens are prepared from.
Technical Paper

DI Boost: Application of a High Performance Gasoline Direct Injection Concept

2007-04-16
2007-01-1410
The development of engines with high specific output and low specific fuel consumption is now more than ever becoming the main focus for powertrain product development. A combination of two primary factors is driving this demand: increased fuel cost and stricter government regulations. As worldwide fuel prices continue to increase, consumers are shifting their purchasing toward more fuel-efficient vehicles. Also fueling the demand is new federal corporate average fuel economy (CAFÉ) regulations that are in place for the timeframe from 2008 to 2011. One concept to provide both high specific output and low specific fuel consumption is the combination of turbocharging and gasoline direct fuel injection. This is an attractive concept for the North American market where sport utility vehicles, light trucks and sports cars of all sizes are in demand from consumers.
Technical Paper

Development of Advanced Metallic Substrate Design for Close Coupled Converter Application

2007-04-16
2007-01-1262
The implementations of the Tier 2 and LEVII emission levels require fast catalyst light-off and fast closed loop control through high-speed engine management. The paper describes the development of innovative catalyst designs. During the development thermal and mechanical boundary conditions were collected and component tests conducted on test rigs to identify the emission and durability performance. The products were evaluated on a Super Imposed Test Setup (SIT) where thermal and mechanical loads are applied to the test piece simultanously and results are compared to accelerated vehicle power train endurance runs. The newly developed light-off catalyst with Perforated Foil Technology (PE) showed superior emission light-off characteristic and robustness.
Technical Paper

Effects of Substrate Diameter and Cell Density FTP Performance

2007-04-16
2007-01-1265
An experiment was performed with a 1.3L catalytic converter design containing a front and rear catalyst each having a volume of 0.65 liters. This investigation varied the front catalyst parameters to study the effects of 1) substrate diameter, 2) substrate cell density, 3) Pd loading and 4) Rh loading on the FTP emissions on three different vehicles. Engine displacement varied from 2.4L to 4.7L. Eight different converters were built defined by a Taguchi L-8 array. Cold flow converter restriction results show the tradeoff in converter restriction between substrate cell density and substrate diameter. Vehicle FTP emissions show how the three vehicles are sensitive to the four parameters investigated. Platinum Group Metals (PGM) prices and Federal Test Procedure (FTP) emissions were used to define the emission value between the substrate properties of diameter and cell density to palladium (Pd) and rhodium (Rh) concentrations.
Technical Paper

Sunroof Buffeting Suppression Using a Dividing Bar

2007-04-16
2007-01-1552
This paper presents the results of CFD study on sunroof buffeting suppression using a dividing bar. The role of a dividing bar in side window buffeting case was illustrated in a previous study [8]. For the baseline model of the selected vehicle in this study, a very high level of sunroof buffeting, 133dB, has been found. The CFD simulation shows that the buffeting noise can be significantly reduced if a dividing bar is installed at the sunroof. A further optimization study on the dividing bar demonstrates that the peak buffeting level can be reduced to 123dB for the selected vehicle if the dividing bar is installed at its optimal location, 65% of the total length from the front edge of the sunroof. The peak buffeting level can be further reduced to 100dB if the dividing bar takes its optimal width 80mm, 15% of the total length of the sunroof for this vehicle, while staying at its optimal location.
Technical Paper

DOE Analysis of Factors Affecting Ultimate Strength of Multiple Resistance Spot Welded Joints

2007-04-16
2007-01-1661
More than 200 tensile-shear resistance spot welded specimens were produced and tested to analyze the effect of spot weld spacing, weld size, sheet thickness, and adhesive on the ultimate strength of joints made from a mild hot dip galvannealed steel and an unexposed quality hot dip galvannealed 590 MPa minimum tensile strength dual phase steel (DP590). The geometric layout parameters were analyzed by a design of experiment (DOE) approach. The analysis showed that weld size is a primary factor affecting the strength of the joints for a given material. It was also determined that structural adhesive created a large relative strengthening for joints made from the mild steel. Interactions of the geometrical factors are also presented.
Technical Paper

Model Simulation Study of Central Composite Design and Uniform Design

2007-04-16
2007-01-1662
The relationship between the response (output) and the input factors on a system or process is always needed. This relationship can be used to optimize the response. The Central Composite Design (CCD) is the most commonly used in response surface study. The Uniform Design (UD) can have a small number of experiments to explore relationship between the response and the factors. In this paper, the physics-based simulation model of a “Heater fan motor” will be used to investigate the accuracy of the response (angular velocity) by the prediction models from CCD and UD.
Technical Paper

Studies of Diesel Particulate Filter Performances by a Diesel Engine Simulator

2010-04-12
2010-01-0813
To evaluate various Diesel Particulate Filter (DPF) efficiently, accelerated tests are one of effective methods. In this study, a simulator composed by diesel fuel burners is proposed for fundamental DPF evaluations. Firstly particle size distribution measurement, chemical composition and thermal analysis were carried out for the particulate matter (PM) generated by the simulator with several combustion conditions. The PMs generated by specific conditions showed similar characteristics to PMs of a diesel engine. Through these investigations, mechanism of PM particle growth was discussed. Secondly diversified DPFs were subjected to accelerated pressure drop and filtration efficiency tests. Features of DPFs could be clarified by the accelerated tests. In addition, the correlation between DPF pressure drop performance and PM characteristics was discussed. Thirdly regeneration performance of the simulator's PM was investigated.
Technical Paper

Performance Verification of Next Generation Diesel Particulate Filter

2010-04-12
2010-01-0531
The Inlet-Membrane DPF which has a small pore size membrane formed on the inlet side of the body wall has been developed as a next generation diesel particulate filter (DPF). It simultaneously realizes low pressure drop, small pressure drop hysteresis, high robustness and high filtration efficiency. The low pressure drop improves fuel economy. The small pressure drop hysteresis has the potential to extend the regeneration interval since the linear relationship between the pressure drop and accumulated soot mass improves the accuracy of the soot mass detection by means of the pressure drop values. The Inlet-Membrane DPF's high robustness also extends the regeneration interval resulting in improved fuel economy and a lower risk of oil dilution while its high filtration efficiency reduces PM emissions. The concept of the Inlet-Membrane DPF was confirmed using disc type filters in 2008 and its performances was evaluated using full block samples in 2009.
Technical Paper

Extension of Lean and Diluted Combustion Stability Limits by Using Repetitive Pulse Discharges

2010-04-12
2010-01-0173
A newly developed small-sized IES (inductive energy storage) circuit with a semiconductor switch at turn-off action was successfully applied to an ignition system. This IES circuit can generate repetitive nanosecond pulse discharges. An ignition system using repetitive nanosecond pulse discharges was investigated as an alternative to conventional spark ignition systems in the previous papers. Experiments were conducted using constant volume chamber for CH₄ and C₃H₈-air mixtures. The ignition system using repetitive nanosecond pulse discharges was found to improve the inflammability of lean combustible mixtures, such as extended flammability limits, shorted ignition delay time, with increasing the number of pulses for CH₄ and C₃H₈-air mixtures under various conditions. The mechanisms for improving the inflammability were discussed and the effectiveness of IES circuit under EGR condition was also verified.
Technical Paper

Water and Heat Balance in a Fuel Cell Vehicle with a Sodium Borohydride Hydrogen Fuel Processor

2003-06-23
2003-01-2271
The National Renewable Energy Laboratory (NREL) collaborated with Millennium Cell and DaimlerChrysler to study heat and water management in a sodium borohydride (NaBH4) storage/processor used to supply hydrogen to a fuel cell in an automotive application. Knowledge of heat and water flows in this system is necessary to maximize the storage concentration of NaBH4, which increases vehicle range. This work helps evaluate the NaBH4 system's potential to meet the FreedomCAR program technical target of 6 wt% hydrogen for hydrogen storage technologies. This paper also illustrates the advantages of integrating the NaBH4 hydrogen processor with the fuel cell.
Technical Paper

An Electro-Mechanical Infinitely Variable Speed Transmission

2004-03-08
2004-01-0354
An electro-mechanical infinitely variable transmission (eVT), comprising a pair of planetary trains interconnected with two electric machines and clutches, has been proposed. The transmission leverages the advantages of an output power-split configuration for low-speed operation and a compound power-split configuration for high-speed operation. It is capable of being operated in a number of operating modes including an eVT only mode and a hybrid mode when equipped with on-board energy storage devices. The transmission provides a compact, highly efficient and potentially low cost driveline solution for both conventional vehicles and hybrid electric vehicles. A virtual transmission prototype was built in EASY51. A base vehicle model was also constructed in EASY5 environment with Ricardo Powertrain Library components.
Technical Paper

Systems Approach to Meeting EPA 2010 Heavy-Duty Emission Standards Using a NOx Adsorber Catalyst and Diesel Particle Filter on a 15L Engine

2004-03-08
2004-01-0587
This paper outlines the development and integration of an advanced emission control system with a modern heavy-duty diesel engine for use in a series of catalyst aging tests. The project that is discussed is one of several being conducted under the Department of Energy's Advanced Petroleum-Based Fuels - Diesel Emission Control (APBF-DEC) activity. This government/industry collaboration is examining how systems of advanced fuels, engines, and emission control systems can deliver significantly lower emissions while maintaining or improving vehicle fuel economy. This project is using a Cummins ISX EGR engine (15 L) with a secondary fuel injection system to enable NOx adsorber catalyst regeneration. Development of the strategies for NOx regeneration and sulfur removal as well as integration of the emission control hardware is discussed. Performance of oven aged systems tested over transient and steady-state cycles is summarized.
Technical Paper

Reaction and Diffusion Phenomena in Catalyzed Diesel Particulate Filters

2004-03-08
2004-01-0696
The objective of this study is to explain the physical and chemical mechanisms involved in the operation of a catalyzed diesel particulate filter. The study emphasizes on the coupling between reaction and diffusion phenomena (with emphasis on NO2 “back-diffusion”), based on modeling and experimental data obtained on the engine dynamometer. The study is facilitated by a novel multi-dimensional mathematical model able to predict both reaction and diffusion phenomena in the filter channels and through the soot layer and wall. The model is thus able to predict the species concentration gradients in the inlet/outlet channels, in the soot layer and wall, taking into account the effect of NO2 back diffusion. The model is validated versus engine dyno measurements. Two sets of measurements are employed corresponding to low-temperature “controlled” regenerations as well as high-temperature “uncontrolled” conditions.
X