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This paper compares various automatic transmission fluids using the Viscosity Loss Trapezoid and shows what relationship exists between the changes in molecular weight distributions and the shear experienced by the fluids.

This paper provides an overview of the dual EGO sensor method for OBD-II catalyst efficiency monitoring. The processes governing the relationship between catalyst oxygen storage, HC conversion efficiency, and rear EGO sensor response are reviewed in detail. A simple physical model relating catalyst oxygen storage capacity and rear EGO sensor response is constructed and used in conjunction with experimental data to provide additional insight into the operation of the catalyst monitor. The effect that the catalyst washcoat formulation has in determining the relationship between catalyst oxygen storage capacity and HC conversion efficiency and its impact on the catalyst monitor is also investigated. Lastly, the effects of catalyst failure mode, fuel sulfur, and the fuel additive MMT on the catalyst monitor's ability to properly diagnose catalyst function are discussed.

An extensive calibration study has been initiated to assess the predictive ability of CFD (Computational Fluid Dynamics) for the aerodynamic design of automotive shapes. Several codes are being checked against a set of detailed wind tunnel measurements on ten car-like shapes. The objective is to assess the ability of numerical analysis to predict the CD (drag coefficient) influence of the rear end configuration. The study also provides a significant base of information for investigating discrepancies between predicted and measured flow fields and for assessing new numerical techniques. This technical report compares STAR-CD predictions to the wind tunnel measurements. The initial results are quite encouraging. Calculated centerline pressure distributions on the front end, underbody and floor compare well for all ten shapes. Wake flow structures are in reasonable agreement for many of the configurations. Drag, lift, and pitching moment trends follow the experimental measurements.

Current demands for high fuel efficiency and low emissions in automotive powerplants have drawn attention to the two-stroke engine configuration. The present study measured trapping and scavenging efficiencies of a firing two-stroke spark-ignition engine by in-cylinder gas composition analysis. Intermediate results of the procedure included the trapped air-fuel ratio and residual exhaust gas fraction. Samples, acquired with a fast-acting electromagnetic valve installed in the cylinder head, were taken of the unburned mixture without fuel injection and of the burned gases prior to exhaust port opening, at engine speeds of 1000 to 3000 rpm and at 10 to 100% of full load. A semi-empirical, zero-dimensional scavenging model was developed based on modification of the non-isothermal, perfect-mixing model. Comparison to the experimental data shows good agreement.

A study was carried out to increase our understanding of the emissions of air toxics from normal and high-emitting vehicles. This study is part of a larger study on fuel effects in high-emitting vehicles, and is part of the Auto/Oil Air Quality Improvement Research Program (AQIRP). Detailed measurements were carried out on the emissions of two vehicles run on industry-average gasoline. The two vehicles, having similar emissions control technologies, represent a high-emitting vehicle and a normal-emitting vehicle. In addition to the regulated emissions (HC, CO, and NOx), a detailed chemical analysis was carried out on the gas - and particle-phase non-regulated emissions. The vehicles were tested over the U.S. EPA UDDS driving schedule. The high emitter was highly variable with regard to emissions, but always operated rich of the stoichiometric point. Up to 46% of fuel carbon was emitted as CO and unburned HC for the high emitter, compared to less than 1.4% for the normal emitter.

Feasibility of wall-flow diesel exhaust filter trap particulate aftertreatment emission control systems to meet the U.S. Federal, CARB, and EC passenger car standards for 1997/2003 and beyond for the 1360 kg (3000 lb.) EAO (Ford European Automotive Operations) 1.8 liter Sierra Turbo-Diesel passenger car is investigated. Plain and Pd catalyzed monolith wall flow diesel particulate traps are examined using Phillips No. 2 diesel fuel (Reference Standard), low sulfur (0.05% S) diesel fuel and an ultra-low sulfur (0.001% S) diesel fuel. Comparisons are made with baseline FTP75 and Highway exhaust emissions and Federal and CARB mandated particulate standards for 1997 and 2003. Effectiveness of catalyzed traps, plain traps, copper octoate trap regeneration fuel additive, and fuel sulfur content on the particulate emissions is determined.

The use of Shadowgraph and Schlieren optical systems is a simple method to determine flow patterns of heated air external to the vehicle at idle. In particular, the method can be used to visualize natural convective air flow patterns at the underbody to aid in heat shielding design. Moreover, air recirculation patterns around the front end of the vehicle can be visualized without the use of smoke. The optical equipment is described and recommendations proposed for setting up the equipment. A video tape of some results is also presented.

Here we present an analytical model, written in general terms, which predicts the trajectory of a spherical particle/droplet placed in a uniform fluid stream. The model is compared to an experiment in which three millimeter diameter polypropolyene spheres (specific gravity = 0.91) are dropped in a uniform airstream (velocity varies from 0.9 to 3.8 m/s). Agreement between the two suggests the model incorporates all the important physics and thus should be useful as a design tool.

Improvements in clamp load retention of fastened joints in instrument panels are desired by automotive OEMs to minimize warranty claims due to squeak and rattle problems. The decrease in torque retention of these plastic boss and metal fastener joints over time and temperature cycling was described in a previous SAE technical paper.1 This loss in clamp load retention (which is another measure of joint durability), as measured by torque, was shown to be affected by differences in the thermal expansion rates of the captured materials. The purpose of this paper is to further quantify these differences by using strain gages to measure the thermal expansion rates and dimensional changes of the joint's various components: metal fastener, molded plastic boss, and captured material.

This report describes an experimental validation of an ellipsoid-to-foam contact model. A series of static foam tests was conducted using Side Impact Dummy rib cage, pelvis, upper leg, and wooden ellipsoids as impactors to validate a theoretical foam contact model previously developed. Predicted results of contact forces, calculated using the uni-axial stress-strain relationship and contact areas, yield good correlation with the test data. These studies used CFC foams and were conducted prior to switching to water-blown foam material development. The ellipsoid-to-foam contact model is being integrated into a MADYMO side impact model. The MADYMO/foam simulation model can then be used to help evaluate design variable tradeoffs (e.g., door thickness vs. body side structures and foam padding requirement vs. interior package) thereby reducing the current dependency on testing, bolster development time, and cost.

A new foam material model has been developed incorporating both theoretical formulation for low-density high-hysteresis foam and test data. Detailed formulation is presented. The finite element analysis of the resilient bumper and the IP head impact are also discussed. A good correlation is concluded by comparing the results from the tests and the FEA simulations.

In joint partnership with its catalyst suppliers, Ford has made significant advances in the performance of Pd-only three way catalyst (TWC) technology through improvements in catalyst oxygen storage. The following manuscript describes in detail the performance advancement of Ford's Pd-only washcoat technology through the use of laboratory, engine dynamometer, and vehicle emission data.

Cyclic variability (CV) in combustion in IC-SI engines, manifested as variation in combustion pressure, is a long term as well as a contemporary problem. CV and its relation to several areas of engine control and diagnostics are discussed. A novel stochastic model relating combustion pressure to crankshaft velocity in an IC-SI engine is presented. This model incorporates a random combustion pressure signal model composed of a deterministic waveform and a random sequence modeling cyclic variation in combustion pressure. A discrete recursion is developed relating this sequence to noisy measurements of velocity. The inverse problem of reconstructing this sequence from one measurement of velocity per combustion is solved using a signal processing deconvolution method. Experimental results using real-world engine data are presented verifying the theoretical developments for low to moderate engine speed and moderate engine load.

This paper describes the design and development of the Ford Driving Simulator. The simulator is a fixed-base device which provides real-time, interactive feedback to the driver through a combination of visual, auditory and tactile cues. The system is comprised of a modular buck, 150° field-of-view visual scene, a steering torque controller, high fidelity dynamics models, and an interactive experimenters station. Data acquisition systems have been developed to capture a broad spectrum of driver performance metrics.

The influence of calcium treatment on the mechanical properties of a plain carbon steel (SAE 1050) was investigated. The mechanical properties investigated were tensile and impact strength, fatigue crack growth rate, and the fatigue threshold. Impact testing was conducted at both room temperature and at -40°C. Several heats of both calcium and non-calcium treated steel (SAE 1050) were tested in both the as hot-rolled condition and in the quenched and tempered condition (with a hardness level of HRC = 45). The results of this investigation show no significant difference in the tensile properties or room temperature impact properties between the calcium treated and the non-calcium treated steels. However, the impact strengths of calcium treated steels were slightly higher than that of non-calcium treated steels at -40°C.

A study was conducted to rank 34 ergonomic characteristics of automobiles by their degree of importance to older and younger drivers. The older drivers were students in AARP driver education classes; the younger drivers were students in university classes. Three geographic locations were sampled. The primary variable analyzed was age, but geographic location, gender, driving experience, and use of glasses were also investigated. Of the characteristics that were found to be of more than average importance to older drivers, seven were appreciably more important to older drivers than to younger drivers with the “control of glare light” being the most dominant.

Increased use of powder-forged connecting rods in the automotive industry prompted an investigation into the suitability of powders from different suppliers for this application. Specifications developed by North American users call for ultra clean powders to enhance machinability and fatigue life. Powders from four manufacturers were each blended with graphite and lubricant, then pressed, sintered and forged to full density. Metallographic samples were prepared and evaluated for inclusion content. In addition, the powders were mixed to the composition of connecting rods, (C - 0.5%, Cu - 2% and MnS - 0.3%), and were similarly pressed, sintered and forged. Test bars were machined from the forged discs. Uniaxial fatigue tests were performed in the tension-compression mode and strain-life curves were developed. It was determined that all powders examined were very clean and were comparable in their inclusion content.

During the fall of 1992, the Michigan Roadside Study was conducted. During this study IM240 tests were conducted on vehicles that had also been emissions tested during on-road operation via two remote sensors that were separated by 100 feet. The use of two remote sensors provided an indication of the short-term real-world emissions variability of a large number of on-road vehicles. This data was used to determine the frequency of flippers, i.e. vehicles that are sometimes high emitters (>4% CO) and at other times low emitters (<2% CO). The data show that the flipper frequency increases for older model year vehicles. Also, the correlations between remote sensor readings of emissions concentrations and IM240 mass emissions rates were determined. The data show that the correlation between remote sensing and IM240 improves with increasing numbers of remote sensing readings. For three remote sensor readings, CO correlates with an r2 of 0.69 and HC correlates with an r2 of 0.54

The feasibility of using experimentally determined flow fields at intake valve closing, IVC, as initial conditions for computing the in-cylinder flow dynamics during the compression stroke is demonstrated by means of a computer simulation of the overall approach. A commercial CFD code, STAR-CD, was used for this purpose. The study involved two steps. First, in order to establish a basis for comparison, the in-cylinder flow field throughout the intake and compression strokes, from intake valve opening, IVO, to top dead center, TDC, was computed for a simple engine geometry. Second, experimental initial conditions were simulated by randomly selecting and perturbing a set of velocity vectors from the computed flow field at IVC.

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.