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Technical Paper

A New Design for Automotive Alternators

This paper introduces a new design for alternator systems that provides dramatic increases in peak and average power output from a conventional Lundell alternator, along with substantial improvements in efficiency. Experimental results demonstrate these capability improvements. Additional performance and functionality improvements of particular value for high-voltage (e.g., 42 V) alternators are also demonstrated. Tight load-dump transient suppression can be achieved using this new design and the alternator system can be used to implement jump charging (the charging of the high-voltage system battery from a low-voltage source). Dual-output extensions of the technique (e.g., 42/14 V) are also introduced. The new technology preserves the simplicity and low cost of conventional alternator designs, and can be implemented within the existing manufacturing infrastructure.
Technical Paper

Time-Resolved, Speciated Emissions from an SI Engine During Starting and Warm-Up

A sampling system was developed to measure the evolution of the speciated hydrocarbon emissions from a single-cylinder SI engine in a simulated starting and warm-up procedure. A sequence of exhaust samples was drawn and stored for gas chromatograph analysis. The individual sampling aperture was set at 0.13 s which corresponds to ∼ 1 cycle at 900 rpm. The positions of the apertures (in time) were controlled by a computer and were spaced appropriately to capture the warm-up process. The time resolution was of the order of 1 to 2 cycles (at 900 rpm). Results for four different fuels are reported: n-pentane/iso-octane mixture at volume ratio of 20/80 to study the effect of a light fuel component in the mixture; n-decane/iso-octane mixture at 10/90 to study the effect of a heavy fuel component in the mixture; m-xylene and iso-octane at 25/75 to study the effect of an aromatics in the mixture; and a calibration gasoline.
Technical Paper

Chain Representations of Dimensional Control: A Producibility Input for Concurrent Concept Design

Two critical milestones that must be achieved during concept design are 1) definition of a product architecture that meets performance, producibility, and strategic objectives, and 2) estimation of the integration risk in each candidate concept. This paper addresses these issues by describing the role played by the producibility members of an Integrated Product Team (IPT) during concept design. Our focus is on the execution of the what we call the “chain method”, which illustrates the structure of function delivery in a concept in a simple pictorial way and helps the IPT to understand the advantages or disadvantages of using a modular or an integral product architecture. The producibility members play a central role in capturing and evaluating the chains for different candidate concepts and decompositions.
Technical Paper

Liquid Fuel Visualization Using Laser-Induced Fluoresence During Cold Start

The presence of liquid fuel inside the engine cylinder is believed to be a strong contributor to the high levels of hydrocarbon emissions from spark ignition (SI) engines during the warm-up period. Quantifying and determining the fate of the liquid fuel that enters the cylinder is the first step in understanding the process of emissions formation. This work uses planar laser induced fluorescence (PLIF) to visualize the liquid fuel present in the cylinder. The fluorescing compounds in indolene, and mixtures of iso-octane with dopants of different boiling points (acetone and 3-pentanone) were used to trace the behavior of different volatility components. Images were taken of three different planes through the engine intersecting the intake valve region. A closed valve fuel injection strategy was used, as this is the strategy most commonly used in practice. Background subtraction and masking were both performed to reduce the effect of any spurious fluorescence.
Technical Paper

The Development of the Advanced Protocol for Automotive Local Area Multiplexing Network (Advanced PALMNET)

In order to expand the applicable range of in-vehicle LANs down to popular cars, drastic cost reduction is essential. In addition, an in-vehicle LAN with high transmission rate and advanced functioning is extremely important for the further spreading of vehicle electronics intended to enhance vehicle intelligence. We developed the Protocol for Automotive Low and Medium Speed Network (PALMNET) as an in-vehicle LAN system and put it into practical use in 1990. Based on this, we developed a new communication protocol and three ICs for an in-vehicle LAN called the Advanced Protocol for Automotive Local Area Multiplexing Network (Advanced PALMNET), which satisfies the above-mentioned requirements and covers the medium-to-low transmission rate (up to 125kbps) to high rate (up to 1Mbps).
Technical Paper

Analysis of Fuel Behavior in the Spark-Ignition Engine Start-Up Process

An analysis method for characterizing fuel behavior during spark-ignition engine starting has been developed and applied to several sets of start-up data. The data sets were acquired from modern production vehicles during room temperature engine start-up. Two different engines, two control schemes, and two engine temperatures (cold and hot) were investigated. A cycle-by-cycle mass balance for the fuel was used to compare the amount of fuel injected with the amount burned or exhausted as unburned hydrocarbons. The difference was measured as “fuel unaccounted for”. The calculation for the amount of fuel burned used an energy release analysis of the cylinder pressure data. The results include an overview of starting behavior and a fuel accounting for each data set Overall, starting occurred quickly with combustion quality, manifold pressure, and engine speed beginning to stabilize by the seventh cycle, on average.
Technical Paper

3D Vortex Simulation of Intake Flow in a Port-Cylinder with a Valve Seat and a Moving Piston

A Lagrangian random vortex-boundary element method has been developed for the simulation of unsteady incompressible flow inside three-dimensional domains with time-dependent boundaries, similar to IC engines. The solution method is entirely grid-free in the fluid domain and eliminates the difficult task of volumetric meshing of the complex engine geometry. Furthermore, due to the Lagrangian evaluation of the convective processes, numerical viscosity is virtually removed; thus permitting the direct simulation of flow at high Reynolds numbers. In this paper, a brief description of the numerical methodology is given, followed by an example of induction flow in an off-centered port-cylinder assembly with a harmonically driven piston and a valve seat situated directly below the port. The predicted flow is shown to resemble the flow visualization results of a laboratory experiment, despite the crude approximation used to represent the geometry.
Technical Paper

Planar Measurements of OH Radicals in an S.I. Engine Based on Laser Induced Flourescence

The planar laser induced fluorescence (PLIF) technique was applied to two dimensional visualization of OH radicals in a combustion flame. A frequency doubled Nd:YAG laser pumped dye laser was used to form a laser light sheet which excited the OH X2Π-A2Σ transition. A fluorescence image of the OH radical and a visible image of a combustion flame were simultaneously imaged by a pair of CCD cameras with image intensifiers. Measurement of the OH radical in the combustion flame could be carried out by using this PLIF technique without Mie scattering lights from soot particles and other optical disturbances. The PLIF technique was employed to study the OH radical in the combustion chamber of a spark ignition (S. I.) engine using gasoline as fuel. Measurements of the OH radical fluorescence were carried out under various operating conditions of mass burned fraction, swirl ratio and air-fuel ratio.
Technical Paper

Development of Capacitance-Loaded Window Antenna for AM/FM Car Radios

Mazda established an original design methodology combining a capacitive coupling technology and transmission line theory, to develop a high performance window antenna for AM/FM radios which construction is very simple to construct and requires no use of any antenna boosters or matching circuits. This paper introduces the design methodology and performance characteristics of the new antenna as well as its application to the production '95 model Mazda 929.
Technical Paper

A Numerical Model of Piston Secondary Motion and Piston Slap in Partially Flooded Elastohydrodynamic Skirt Lubrication

This paper presents a numerical model of the rotational and lateral dynamics of the piston (secondary motion) and piston slap in mixed lubrication. Piston dynamic behavior, frictional and impact forces are predicted as functions of crank angle. The model considers piston skirt surface waviness, roughness, skirt profile, thermal and mechanical deformations. The model considers partially-flooded skirt and calculates the pressure distributions and friction in the piston skirt region for both hydrodynamic and boundary lubrication. Model predictions are compared with measurements of piston position using gap sensors in a single-cylinder engine and the comparison between theory and measurement shows remarkable agreement.
Technical Paper

Engine-Out “Dry” Particular Matter Emissions from SI Engines

The Engine-Out Particulate Matter (EOPM) was collected from a spark ignition engine operating in steady state using a heated quartz fiber filter. The samples were weighted to obtain an EOPMindex and were analyzed using Scanning Electron Microscopy. The EOP Mindex was not sensitive to the engine rpm and load. When the mixture is very rich (air equivalence ratio λ less than ∼ 0.7), the EOPM comprise mostly of soot particles from fuel combustion. In the lean to slightly rich region (0.8 < λ < 1.2), however, the EOPM are dominated by particles derived from the lubrication oil.
Technical Paper

Flame Shape Determination Using an Optical-Fiber Spark Plug and a Head-Gasket Ionization Probe

A method for determining the flame contour based on the flame arrival time at the fiber optic (FO) spark plug and at the head gasket ionization probe (IP) locations has been developed. The experimental data were generated in a single-cylinder Ricardo Hydra spark-ignition engine. The head gasket IP, constructed from a double-sided copper-clad circuit board, detects the flame arrival time at eight equally spaced locations at the top of the cylinder liner. Three other IP's were also installed in the cylinder head to provide additional intermediate data on flame location and arrival time. The FO spark plug consists of a standard spark plug with eight symmetrically spaced optical fibers located in the ground casing of the plug. The cylinder pressure was recorded simultaneously with the eleven IP signals and the eight optical signals using a high-speed PC-based data acquisition system.
Technical Paper

Making the Case for a Next Generation Automotive Electrical System

Introduction of an array of new electrical and electronic features into future vehicles is generating vehicle electrical power requirements that exceed the capabilities of today's 14 volt electrical systems. In the near term (5 to 10 years), the existing 14V system will be marginally capable of supporting the expected additional loads with escalating costs for the associated charging system. However, significant increases in vehicle functional content are expected as future requirements to meet longer-term (beyond 10 years) needs in the areas of emission control, fuel economy, safety, and passenger comfort. A higher voltage electrical system will be required to meet these future requirements. This paper explores the functional needs that will mandate a higher voltage system and the benefits derivable from its implementation.
Technical Paper

Visualization of Mixture Preparation in a Port-Fuel Injection Engine During Engine Warm-up

The fuel injection process in the port of a firing 4-valve SI engine at part load and 25°C head temperature was observed by a high speed video camera. Fuel was injected when the valve was closed. The reverse blow-down flow when the intake valve opens has been identified as an important factor in the mixture preparation process because it not only alters the thermal environment of the intake port, but also strip-atomizes the liquid film at the vicinity of the intake valve and carries the droplets away from the engine. In a series of “fuel-on” experiments, the fuel injected in the current cycle was observed to influence the fuel delivery to the engine in the subsequent cycles.
Technical Paper

Detection of Transient Noise of Car Interior Using Non-stationary Signal Analysis

A method to inspect the rattle generated in a vehicle cabin has been developed. In the method, the waveform of overall in-cabin noise is analyzed using Wigner distribution, a kind of time-frequency analysis, and the rattle component of the waveform is condensed and separated from the background shake noise. Then the rattle component is classified into three levels, strong, middle and not detected, using a neural network. Fuzzy inference is also used to select normal waveform data. Experimental results show that the correct classification ratio of the method is more than 90%, which equals the ability of skilled inspectors.
Technical Paper

An Evaluation of Multiplexing System for Automotive Distributed Control

On board multiplexing communication system is regarded as a necessary technology for the future of electronic system in automobiles. Many companies are developing multiplexing systems and the ISO and SAE are active in establishing standards for communication protocols. The proposed communication protocol specifications have different specifications. Consequently, no compatible evaluation standards existed, and it was difficult to compare one protocol to another. Therefore, to assist the standardization activities of the IS0 and SAE, we have developed an evaluation method for distributed multiplexed communication systems and evaluated each of the proposed protocols using this method. These evaluations were performed from the point of view of the future users of these systems. In this paper we present the results of the experiments on distributed multiplexed communication systems each of which consists of communication IC and the proposed physical layer.
Technical Paper

Protocol for Automotive Local Area Network (PALNET)—A Newly Developed In-Vehicle Communication System Based on SAE J1850

At present, various communication protocols for an automotive distributed control multiplex system that aims at solving wire complexity and meeting the requirements of high reliability and open system flexibility have been proposed and installed in production cars. The requirements for an automotive distributed multiplex system, especially reliability, flexibility, and economy have been analyzed in detail, and as a result a new communication protocol based on SAE J-1850 has been developed. This paper describes the design philosophy and technical features of the protocol, named PALNET (Protocol for Automotive Local area Network) and the result of evaluation with the experimental system. PALNET covers moderate speed signals in vehicle electrical and electronic system. Main technical features of PALNET are as follows. Introduction of a new acknowledgement method named ANC (Acknowledgement for Network Control) secures high reliability of data communication.
Technical Paper

Computational Study of the Aerodynamic Behavior of a Three-Dimensional Car Configuration

Three-dimensional flows around a car configuration, a Mazda RX-7, were computed by directly integrating the governing unsteady, incompressible Navier-Stokes equations. A well-established finite-difference procedure was utilized. The basic equations were formulated in a generalized coordinate system. A third-order upwind scheme was applied to discretize the equations, and the numerical solutions were acquired without using any explicit turbulence models. Elaborate numerical results were presented at a high Reynolds number, Re=106 (based on the body length). In order to investigate the influence of the cross wind, computations were carried out for two yaw angles, i.e., 0 degree and 30 degrees. Extensive flow visualizations, using state-of-the-art computer graphics, were performed; details of the three-dimensional flow structure were examined. Well-controlled wind tunnel experiments were also conducted.
Technical Paper

M.I.T. Stirling-Cycle Heat Transfer Apparatus

The paper describes the design and construction of a two cylinder apparatus to measure heat transfer under conditions of oscillating pressure and oscillating flow such as found in Stirling-cycle machines. The apparatus consists of two large single stage air compressors joined by a rigid drive shaft between the two crank shafts. The compressors are 27.94 cm (11-in) diameter by 22.86 cm (9-in) stroke. The apparatus is powered by a 25 HP variable speed DC motor. Belts and a jack shaft provide wide speed ranges. The test section, which is connected between the compressor cylinders, is a 44.45 mm (1.75-in) diameter tube and about 254 cm (100-in) long. The test section is configured for measuring wall heat flux, and gas pressure as a function of time. An LDV system is being installed for measurement of gas velocity as a function of time and position. A fast response micro thermocouple measures gas temperature as a function of time and position.
Technical Paper

A CAD-Driven Flexible Forming System for Three-Dimensional Sheet Metal Parts

A novel system for the forming of three dimensional sheet metal parts is described that can form a variety of part shapes without the need for fixed tooling, and given only geometry (CAD) information about the desired part. The central elements of this system are a tooling concept based on a programmable discrete die surface and closed-loop shape control. The former give the process the degrees of freedom to change shape rapidly, and the latter is used to insure that the correct shape is formed with a minimum of forming trials. A 540 kN (60 ton) lab press has been constructed with a 0.3 m (12 in) square pair of discrete tools that can be rapidly re-shaped between forming trials. The shape control system uses measured part shapes to determine a shape error and to correct the tooling shape. This correction is based on a unique “Deformation Transfer Function” approach using a spatial frequency decomposition of the surface.