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Catalyzed Particulate Filter Passive Oxidation Study with ULSD and Biodiesel Blended Fuel

A 2007 Cummins ISL 8.9L direct-injection common rail diesel engine rated at 272 kW (365 hp) was used to load the filter to 2.2 g/L and passively oxidize particulate matter (PM) within a 2007 OEM aftertreatment system consisting of a diesel oxidation catalyst (DOC) and catalyzed particulate filter (CPF). Having a better understanding of the passive NO2 oxidation kinetics of PM within the CPF allows for reducing the frequency of active regenerations (hydrocarbon injection) and the associated fuel penalties. Being able to model the passive oxidation of accumulated PM in the CPF is critical to creating accurate state estimation strategies. The MTU 1-D CPF model will be used to simulate data collected from this study to examine differences in the PM oxidation kinetics when soy methyl ester (SME) biodiesel is used as the source of fuel for the engine.
Technical Paper

The Effects of Different Input Excitation on the Dynamic Characterization of an Automotive Shock Absorber

This paper deals with the dynamic characterization of an automotive shock absorber, a continuation of an earlier work [1]. The objective of this on-going research is to develop a testing and analysis methodology for obtaining dynamic properties of automotive shock absorbers for use in CAE-NVH low-to-mid frequency chassis models. First, the effects of temperature and nominal length on the stiffness and damping of the shock absorber are studied and their importance in the development of a standard test method discussed. The effects of different types of input excitation on the dynamic properties of the shock absorber are then examined. Stepped sine sweep excitation is currently used in industry to obtain shock absorber parameters along with their frequency and amplitude dependence. Sine-on-sine testing, which involves excitation using two different sine waves has been done in this study to understand the effects of the presence of multiple sine waves on the estimated dynamic properties.
Technical Paper

Prediction Technique for Vibration of Power-Plant with Elastic Crankshaft System

The dynamic behaviors of power-plant have much effect on interior noises and vibrations of passenger cars, especially, in the frequency range below 1000 Hz. So it is very important to estimate the vibrations of power-plant at the design stage. To predict the dynamic behaviors of power-plant including the rotating elastic crankshaft system, the time domain dynamic simulation methods have been applied, however such analyses require much time and resource of computer. In this report, the exciting forces to the cylinder block are derived in the frequency domain from both the dynamic stiffness of bearing oil films and the dynamic displacements of crankshaft journals, so that the computation time is reduced considerably. To estimate the displacements of the crankshaft journals, the vibrations of an engine crankshaft system including crank journal oil films under firing conditions are calculated using the dynamic stiffness matrix method in the frequency domain.
Technical Paper

External Corrosion Resistance of CuproBraze® Radiators

New technology for the manufacturing of copper/brass heat exchangers has been developed and the first automotive radiators are already in operation in vehicles. This new technology is called CuproBraze®. One of the essential questions raised is the external corrosion resistance with reference to the present soldered copper/brass radiators and to the brazed aluminium radiators. Based on the results from electrochemical measurements and from four different types of accelerated corrosion tests, the external corrosion resistance of the CuproBraze® radiators is clearly better than that of the soldered copper/brass radiators and competitive with the brazed aluminum radiators, especially as regards marine atmosphere. Due to the relatively high strength of the CuproBraze® heat exchangers, down gauging of fins and tubes in some applications is attractive. High performance coatings can ensure long lifetime from corrosion point of view, even for thin gauge heat exchangers.
Technical Paper

The Effects of Natural Aging on Fleet and Durability Vehicle Engine Mounts from a Dynamic Characterization Perspective

Elastomers are traditionally designed for use in applications that require specific mechanical properties. Unfortunately, these properties change with respect to many different variables including heat, light, fatigue, oxygen, ozone, and the catalytic effects of trace elements. When elastomeric mounts are designed for NVH use in vehicles, they are designed to isolate specific unwanted frequencies. As the elastomers age however, the desired elastomeric properties may have changed with time. This study looks at the variability seen in new vehicle engine mounts and how the dynamic properties change with respect to miles accumulated on fleet and durability test vehicles.
Technical Paper

Material Damping Properties: A Comparison of Laboratory Test Methods and the Relationship to In-Vehicle Performance

This paper presents the damping effectiveness of free-layer damping materials through standard Oberst bar testing, solid plate excitation (RTC3) testing, and prediction through numerical schemes. The main objective is to compare damping results from various industry test methods to performance in an automotive body structure. Existing literature on laboratory and vehicle testing of free-layer viscoelastic damping materials has received significant attention in recent history. This has created considerable confusion regarding the appropriateness of different test methods to measure material properties for damping materials/treatments used in vehicles. The ability to use the material properties calculated in these tests in vehicle CAE models has not been extensively examined. Existing literature regarding theory and testing for different industry standard damping measurement techniques is discussed.
Technical Paper

Fuel Evaporation Parameter Identification during SI Cold Start

The stochastic properties of continuous time model parameters obtained through discrete least squares estimation are examined. Particular attention is given to the application of estimating the fuel evaporation dynamics of a V-8 SI engine. The continuous time parameter distributions in this case are biased. The bias is shown to be a function of both measurement noise and sampling rate selection. Analysis and experimental results suggest that for each particular model, there is a corresponding optimum sampling rate. A bias compensation formula is proposed that improves the accuracy of least squares estimation without iterative techniques.
Technical Paper

Control Strategies for a Series-Parallel Hybrid Electric Vehicle

Living in the era of rising environmental sensibility and increasing gasoline prices, the development of a new environmentally friendly generation of vehicles becomes a necessity. Hybrid electric vehicles are one means of increasing propulsion system efficiency and decreasing pollutant emissions. In this paper, the series-parallel power-split configuration for Michigan Technological University's FutureTruck is analyzed. Mathematical equations that describe the hybrid power-split transmission are derived. The vehicle's differential equations of motion are developed and the system's need for a controller is shown. The engine's brake power and brake specific fuel consumption, as a function of its speed and throttle position, are experimentally determined. A control strategy is proposed to achieve fuel efficient engine operation. The developed control strategy has been implemented in a vehicle simulation and in the test vehicle.
Technical Paper

NVH Experimental Analyses for an Engine Structure Model Assembled with Ordinary Tap Bolts and with Through Bolts

A series of NVH experiments were performed for a set of single cylinder engine models made of aluminum, consisting of a cylinder head, a cylinder block and a bed-plate. Each has the same outer size of 150mm × 150mm; the different heights are 100mm, 200mm and 80mm respectively. Those dimensions were determined following the dimensions for a diesel engine in lightweight commercial vehicle with the bore size of 100mm and the crankshaft main bearing diameter of 60mm. We chose 112 of measuring points on the structure surfaces and performed a series of impact tests, for the following cases: (a) When the cylinder head and the bed-plate were fastened to the cylinder block by two sets of four ISO M10 tap-bolts, each with the lengths ℓ1 =117mm and ℓ2 =97mm. (b) When the cylinder head and the bed-plate were fastened to the cylinder block together by a set of four ISO M10 through-bolts of grip length ℓ3 =380mm.
Technical Paper

LES and RNG Turbulence Modeling in DI Diesel Engines

The one-equation subgrid scale model for the Large Eddy Simulation (LES) turbulence model has been compared to the popular k-ε RNG turbulence model in very different sized direct injection diesel engines. The cylinder diameters of these engines range between 111 and 200 mm. This has been an initial attempt to study the effect of LES in diesel engines without any modification to the combustion model being used in its Reynolds-averaged Navier-Stokes (RANS) form. Despite some deficiencies in the current LES model being used, it already gave much more structured flow field with approximately the same kind of accuracy in the cylinder pressure predictions than the k-ε RNG turbulence model.
Technical Paper

A Cascade Atomization and Drop Breakup Model for the Simulation of High-Pressure Liquid Jets

A further development of the ETAB atomization and drop breakup model for high pressure-driven liquid fuel jets, has been developed, tuned and validated. As in the ETAB model, this breakup model reflects a cascade of drop breakups, where the breakup criterion is determined by the Taylor drop oscillator and each breakup event resembles experimentally observed breakup mechanisms. A fragmented liquid core due to inner-nozzle disturbances is achieved by injecting large droplets subject to this breakup cascade. These large droplets are equipped with appropriate initial deformation velocities in order to obtain experimentally observed breakup lengths. In contrast to the ETAB model which consideres only the bag breakup or the stripping breakup mechanism, the new model has been extended to include the catastrophic breakup regime. In addition, a continuity condition on the breakup parameters has lead to the reduction of one model constant.
Technical Paper

Drawbeads in Sheet Metal Stamping - A Review

The paper reviews the role of drawbeads in sheet metal stamping. The design of drawbeads is discussed in depth, with treatment of different bead cross sections, bead end shapes, and bead materials. International standards and practices are included. This is followed by the historical development of the modeling of the drawbead restraining force, starting with basic equilibrium approaches, and leading to the use of the finite element method which permits the study of drawbead effects on sheet metal flow in three dimensions. Finally, the potential of active drawbeads is described based upon ongoing research which is directed toward closed-loop computer control of the stamping process through adjustment of the drawbead penetration.
Technical Paper

Convergence of Laboratory Simulation Test Systems

Laboratory Simulation Testing is widely accepted as an effective tool for validation of automotive designs. In a simulation test, response data are measured whilst a vehicle is in service or tested at a proving ground. These responses are reproduced in the laboratory by mounting the vehicle or a subassembly of the vehicle in a test rig and applying force and displacements by servo hydraulic actuators. The data required as an input to the servo hydraulics, the drive files, are determined by an iterative procedure which overcomes the non linearity in the test specimen and the test rig system. Under certain circumstances, the iteration does not converge, converges too slowly or converges and then diverges. This paper uses mathematical and computer models in a study of the reasons why systems fail to convergence and makes recommendations about the management of the simulation test.
Technical Paper

Effects of Fuel Injection Rate on Combustion and Emission in a DI Diesel Engine

Fuel injection rate pattern represents an important factor for emissions reduction. In this study, fuel spray photography, combustion photography and experimental data analysis indicate. 1) effect of pilot injection 2) effect of a gradual shaped injection profile using nozzle needle lift control 3) effect of a boot shaped injection profile using pressure control Common rail type fuel injection equipment was used in these experiments, and the engine was single cylinder naturally aspirated D.I. diesel engine. As a result, we found out that it is important to control the pre-mixed combustion for NOx reduction and to activate the diffusion combustion for smoke, and various fuel injection rate patterns we studied have similar effect on combustion and emissions at the most suitable condition respectively.
Technical Paper

A Study of the Vapor- and Particle-Phase Sulfur Species in the Heavy-Duty Diesel Engine EGR Cooler

To meet future NO, heavy-duty diesel emissions standards, exhaust gas recirculation (EGR) technology is likely to be used. To improve fuel economy and further lower emissions, the recirculated exhaust gas needs to be cooled, with the possibility that cooling of the exhaust gas may form sulfuric acid condensate in the EGR cooler. This corrosive condensate can cause EGR cooler failure and consequentially result in severe damage to the engine. Both a literature review and a preliminary experimental study were conducted. In this study, a manually controlled EGR system was installed on a 1995 Cummins Ml l-330E engine which was operated at EPA mode 9* (1800 rpm and 75% load). The Goksoyr-Ross method (1)** was used to measure the particle-phase sulfate and vapor-phase H2SO4 and SO2 at the inlet and outlet locations of the EGR cooler, obtaining H2SO4 and SO2 concentrations. About 0.5% of fuel sulfur in the EGR cooler was in the particle-phase.
Technical Paper

Numerical Calculation of Spray Mixing Process in a D.I. Diesel Engine and Comparison with Experiments

Three dimensional computational model has been developed to predict the macroscopic behavior of the fuel spray in D. I. diesel engines. The model was based on the KIVA-II code with modification of some submodels that it can deal with the observed phenomena such as liquid column near the nozzle tip and spray impingement on a wall. Firstly, this model was verified by comparing the prediction with the experimental results in a constant volume vessel. Secondly with application to a D.I. diesel engine, the detailed behavior of the spray in a combustion chamber was revealed. Moreover, the engine performance under different spray angles were discussed with the prediction of this model.
Technical Paper

A Study of the Effects of Chamber Geometries on Flame Behavior in a DI Diesel Engine

An experimental study aiming to investigate the effects of combustion chamber geometry on combustion process has been carried out in an optically accessible DI diesel engine. The combustion processes of three different chamber geometries, included the production type, were revealed and the flame movement behaviors such as the distribution of flame velocity vectors and the averaged flame velocity inside and outside the combustion chamber were measured by means of a cross-correlation method. Meanwhile, an endoscope system was used to acquire information about the distribution of flames inside and outside the chamber. BY comparing the flame movement and distribution between different chambers and nozzle protrusions, the results showed that; The chamber geometry has significant effect on the flame velocity, the flame velocities of the reentrant chamber were larger than that of the dish chamber during expansion period.
Technical Paper

A Study of Diesel Combustion Process Under the Condition of EGR and High-Pressure Fuel Injection with Gas Sampling Method

It is well known that a high-pressure fuel injection is effective for the reduction in particulates and smoke emissions. Exhaust gas recirculation (EGR) is effective for the reduction in NOX emission. In this study an experiment aiming to understand more comprehensive combustion under the condition of EGR and high-pressure fuel injection was carried out by using gas sampling method for the purpose of understanding what occurred inside the spray before and after combustion. The number of combustion cycles in this engine can be controlled in order to change EGR conditions by adjusting the residual gas concentration in the cylinder. Main results were: (1) Close to the nozzle tip, the sampling gas data showed little reaction which implies that combustion never occurs in this area during the injection period. (2) In the case of high-pressure fuel injection O2 concentration decreased faster and air dilution was more active and earlier.
Technical Paper

The Optimization of Engine Vibration Reduction by Simulation Analysis

This paper describes a method for effectively reducing a level of idling vibration in heavy-duty trucks, which has been the point at issue lately. In this method, the vibration level is significantly reduced by using a full vehicle model, which is made by finite elements, and varying parameters to study effects. In order to achieve high accuracy, engine excitation forces calculated from the measured fluctuation in the flywheel angular velocity are input to the model. An effective use of this method in an early development stage has enabled us to reduce development cost and the lead-time.
Technical Paper

A Study on the Noise Generating Mechanism of a Fuel Injection Pump

This paper has clarified the noise generating mechanism on the BOSCH AD type fuel injection pump by using numerical and experimental analysis methods. The calculated vibration of each part has been verified to coincide well with the measured acceleration data. Based on the detailed analysis, the major noise source of the injection pump was found to originate from the tappet vibration caused by the steep pressure drop at the end of injection. After performing some parameter studies by using the simulation model, it turned out that some specifications of the injection pump influenced its sound power.