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Many powertrain structural sub-systems are often tested under steady state conditions on a dynamometer or in a full vehicle. This process (while necessary) is costly and time intensive, especially when evaluating the effect of component properties on transient phenomena, such as driveline clunk. This paper proposes a laboratory experiment that provides the following: 1) a bench experiment that demonstrates transient behavior of a non-linear clutch damper under non-rotating conditions, 2) a process to efficiently evaluate multiple non-linear clutch dampers, and 3) generates benchmark time domain data for validation of non-linear driveline simulation codes. The design of this experiment is based on a previous experimental work on clunk. A commercially available non-linear clutch damper is selected and the experiment is sized accordingly. The stiffness and hysteresis properties of the clutch damper are assumed from the measured quasi-static torque curve provided by the manufacturer.

When developing a new engine control strategy, some of the important issues are cost, resource minimization, and quality improvement. This paper outlines how a model based approach was used to develop an engine control strategy for an Extended Range Electric Vehicle (EREV). The outlined approach allowed the development team to minimize the required number of experiments and to complete much of the control development and calibration before implementing the control strategy in the vehicle. It will be shown how models of different fidelity, from map-based models, to mean value models, to 1-D gas dynamics models were generated and used to develop the engine control system. The application of real time capable models for Hardware-in-the-Loop testing will also be shown.

An ignition delay correlation was developed for a toluene reference fuel (TRF) blend that is representative of automotive gasoline fuels exhibiting two-stage ignition. Ignition delay times for the autoignition of a TRF 91 blend with an antiknock index of 91 were predicted through extensive chemical kinetic modeling in CHEMKIN for a constant volume reactor. The development of the correlation involved determining nonlinear least squares curve fits for these ignition delay predictions corresponding to different inlet pressures and temperatures, a number of fuel-air equivalence ratios, and a range of exhaust gas recirculation (EGR) rates. In addition to NO control, EGR is increasingly being utilized for managing combustion phasing in spark ignition (SI) engines to mitigate knock. Therefore, along with other operating parameters, the effects of EGR on autoignition have been incorporated in the correlation to address the need for predicting ignition delay in SI engines operating with EGR.

Two-stage turbochargers are a recent solution to improve engine performance, reducing the turbo-lag phenomenon and improving the matching. However, the definition of the control system is particularly complex, as the presence of two turbochargers that can be in part operated independently requires effort in terms of analysis and optimization. This work documents a characterization study of two-stage turbocharger systems. The study relies on a mean-value model of a Diesel engine equipped with a two-stage turbocharger, validated on experimental data. The turbocharger is characterized by a VGT actuator and a bypass valve (BPV), both located on the high-pressure turbine. This model structure is representative of a “virtual engine”, which can be effectively utilized for applications related to analysis and control. Using this tool, a complete characterization was conducted considering key operating conditions representative of FTP driving cycle operations.

Improper roll pass designs can lead to either underfill which results in the formation of hairline cracks on the surface of the finished bars or overfill which results in roll overloading and the formation of fins. Therefore to reduce downtime, and improve yield and quality, it becomes important to design an acceptable roll pass in reasonable time. This paper presents a methodology for roll pass design which uses a three dimensional finite element technique along with an empirical procedure to arrive at an iterative scheme for reducing the number of passes and improving metal flow in the passes. This methodology is applied to improving an existing seven pass square - to - round rolling sequence, resulting in the reduction of the number of passes and improved distributions of effective strains in the rolled product.

The effectiveness of the Helmholtz resonator as a narrow band acoustic attenuator, particularly at low frequencies, makes it a highly desirable component in a wide variety of applications, including engine breathing systems. The present study investigates the influence of mean flow grazing over the neck of such a configuration on its acoustic performance both computationally and experimentally. Three-dimensional unsteady, turbulent, and compressible Navier-Stokes equations are solved by using the Pressure-Implicit-Splitting-of-Operators algorithm in STAR-CD to determine the time-dependent flow field. The introduction of mean flow in the main duct is shown to reduce the peak transmission loss and shift the fundamental resonance frequency to a higher value.

Crankshaft angular position measurements are fundamental to all modern automotive engines. These measurements are required to control fuel injection timing as well as ignition timing. However, many other functions can be performed from such measurements through the use of advanced signal processing. These additional functions are essentially diagnostic in nature although there is potential for substitution of primary fuel and ignition control functions. This paper illustrates the application of crankshaft angular position measurement to the estimation of individual cylinder indicated and/or brake torque in IC engines from measurement of crankshaft position/velocity.

Performance characteristics of passive, active, and broadband adaptive engine mounts are compared over a wide frequency range up to 250 Hz in the context of a quarter-vehicle heave model. The optimal damping coefficient of a rubber-metal mount is determined using random vibration theory. The small-scale active mount employs proportional-plus-integral control based on linear optimal control theory. The new adaptive hydraulic mount system implements an on-off damping control mode by using engine intake-manifold vacuum and a microprocessor-based solenoid valve controller. Through analytical methods, it is observed that this adaptive mount provides most desirable dynamic performance with regard to the engine-bounce control, shock absorption and vibration isolation performance requirements. Although technical prospects of the proposed adaptive system appear promising, in-situ performance needs to be evaluated.

Flow fields generated during the intake stroke of a 4-stroke I.C. engine are studied experimentally using water analog simulation. The fluid is seeded by small flow tracer particles and imaged by two digital cameras at BDC. Using a 3-D Particle Tracking Velocimetry technique recently developed, the 3-D motion of these flow tracers is determined in a completely automated way using sophisticated image processing and PTV algorithms. The resulting 3-D velocity fields are ensemble averaged over a large number of successive cycles to determine the mean characteristics of the flow field as well as to estimate the turbulent fluctuations. This novel technique was applied to three different cylinder head configurations. Each configuration was run for conditions simulating idle operation two different ways: first with both inlet ports open and second with only the primary port open.

A mathematical basis for predicting loaded off-line of action contact at the tips of undermodified gear teeth is discussed. Two methods of solving the contact problem, using a modified simplex algorithm, are used to predict the load distribution. The methods differ in the compliance matrix formulation and the way they search for contact. The first method uses a tapered plate model and the second method uses a finite element model. The effects of off-line of action contact on load sharing, effective contact ratio and motion curves are shown.

A prototype CO sensor based on anatase TiO2 was fabricated and tested in a Ford V6 engine. Fuel combustion was programmed to be near stoichiometric conditions, and emissions were monitored with an FT-IR analytical instrument. The sensor, positioned near the oxygen sensor in the exhaust manifold, was successfully tested for 50 cycles of revving and idling, and was observed to respond quickly and reproducibly. The sensor response was correlated to the CO concentration at specific engine temperatures and was found to vary systematically with increasing concentrations. This sensor has promising potentials to monitor the efficiency of the catalytic converter.

A new semi-analytical framework for the study of passive or active engine mounting systems is presented. It recognizes that most practical problems incorporate a nonlinear mount or isolation element and the resulting physical system, consisting of the engine, mount and flexible base, involves many degrees of freedom. Unlike linear systems, sinusoidal excitation produces a periodic response, including super- and sub- harmonics. Two example case systems are employed to illustrate key concepts of the framework. The first numerical example case involves a passive hydraulic engine mount with an inertia track. The second example case is a novel experimental system that has been developed to study active and passive, nonlinear mounting problems. New analytical and experimental results are presented and various nonlinear phenomena are considered. The impact of nonlinearity on vibratory power transmission and active control is also investigated.

A number of automotive diagnostic equipment and procedures have evolved over the last two decades, leading to two generations of on-board diagnostic requirements (OBDI and OBDII), increasing the number of components and systems to be monitored by the diagnostic tools. The goal of On-Board Diagnostic is to alert the driver to the presence of a malfunction of the emission control system, and to identify the location of the problem in order to assist mechanics in properly performing repairs. The aim of this paper is to suggest a methodology for the development of an Integrated Powertrain Diagnostic System (EPDS) that can combine the information supplied by conventional tailpipe inspection programs with onboard diagnostics to provide fast and reliable diagnosis of malfunctions.

There is currently a large effort in industry to make natural gas a viable alternative fuel for internal combustion engines. While the use of natural gas offers several advantages such as reduced emissions and potentially higher efficiency, it also has some inherent difficulties. Among these is the challenge of producing a consistently homogeneous air/fuel mixture while retaining the advantages which accompany modern, multi-point, fuel injection systems. The purpose of the research described here is to investigate the in-cylinder mixture formation process in a port injected natural gas fueled engine. Planar laser-induced fluorescence has been used to produce qualitative air fuel ratio maps in the engine cylinder, in selected planes, throughout the intake and compression strokes. The process consists of impinging a sheet of ultraviolet laser light on various planes parallel to, and normal to, the cylinder axis.

The automotive NVH research infrastructure at Ohio State includes the Center for Automotive Research, the Acoustics and Dynamics Laboratory, and the Gear Dynamics and Gear Noise Research Laboratory. This paper describes the facilities of these laboratories. Two unique existing facilities, namely the transmission error measurement of gears and a laboratory for the experimental measurement of engine breathing systems, will be emphasized. Also covered are the enhancements that are envisioned through a recent grant from the Ohio Board of Regents.

This paper presents a concept for enhancing catalytic removal of pollutant species from an exhaust stream by placing placing the plasma adjacent to the catalyst surface. Model calculations of the behavior of the electron energy distribution function (EEDF), which influences the chemistry and ionization levels near the surface, are performed and analyzed. Preliminary experiments attempting to reduce these theoretical ideas to practice in N2/NO mixtures, are discussed. Although removal of NO is observed, this is due to gas phase effects alone. The present experimental arrangement is not able to produce the requisite conditions outlined by theory to enact plasma-enhanced catalysis.

One obstacle hindering the use of port fuel injection in natural gas engines is poor idle performance due to incomplete mixing of the cylinder charge prior to ignition. Fuel injection timing has a strong influence on the mixing process. The purpose of this work is to determine the impact of fuel injection timing on in-cylinder fuel distribution. Equivalence ratio maps have been acquired by Planar Laser Induced Fluorescence in an optical engine with a production cylinder head. Experimental results have been used to determine the injection timing which produces the most uniform fuel distribution for the given engine.

The evolution of the diagnostic equipment for automotive application is the direct effect of the implementation of sophisticated and high technology control systems in the new generation of passenger cars. One of the most challenging issues in automotive diagnostics is the ability to assess, to analyze, and to integrate all the information and data supplied by the vehicle's on-board computer. The data available might be in the form of fault codes or sensors and actuators voltages. Moreover, as environmental regulations get more stringent, knowledge of the concentration of different species emitted from the tailpipe during the inspection and maintenance programs can become of great importance for an integrated powertrain diagnostic system. A knowledge-based diagnostic tool is one of the approaches that can be adopted to carry out the challenging task of detecting and diagnosing faults related to the emissions control system in an automobile.

In this paper, we will present parametric results of performing dynamic analysis of layshaft gear trains typically used in automotive transmissions with emphasis on the vibratory response due to transmission error excitation. A three-dimensional multiple degrees of freedom lumped parameter dynamic model of a generic layshaft type geared rotor system (with three parallel rotating shafts coupled by two sets of gear pairs) has been formulated analytically. The model includes the effects of both rotational and translational displacements of each gears, and bounce and pitch motions of the counter-shaft. The natural frequencies and mode shapes are computed numerically by solving an eigenvalue problem derived from applying harmonic solutions to the equations of motion. The complete set of mode shapes are then used in forced response calculations based on the modal expansion method to predict gear accelerations, dynamic transmission errors, mesh force and bearing loads.

Welding residual stress is one of the primary factors responsible for cracking at the access hole interface between the flange and web plate of welded heavy W-shapes. During multi-pass welding, cracks can be found in either the flange plate or the web plate, depending upon welding sequence, joint details and access hole size. In this study, an integrated numerical and experimental investigation was conducted to evaluate the effects of welding parameters and joint geometry on the magnitude and distribution of residual stresses in thick-section butt joints. The results provide guidelines for improved design for welding of heavy W-shapes.