Search Results

Several parameters which affect the fuel consumption, performance, and top speed of a vehicle are vehicle weight, tire rolling resistance, aerodynamic drag and driveline configuration. Studies have indicated that it is possible to change each of these parameters to reduce the fuel consumption of a vehicle. However, the resulting performance characteristics must also be evaluated over the range of any changes. The purpose of this paper is to assess these vehicle design variables with respect to top speed, performance, and fuel economy. Six vehicles representative of 1978–1979 small, mid-size, and large automobiles and light duty trucks were selected for this study. By utilizing a vehicle simulation program the vehicles were run over the FTP urban and highway drive cycle schedule, and various performance schedules. The results are evaluated qualitatively and quantitatively with respect to the sensitivity of the dependent variables to changes in the independent variables.

The methods of measuring roughness peak count on cold-rolled sheet are discussed. The amplitude dependence of the present recommended peak-count practice is determined. A new method of peak counting that is independent of roughness amplitude and readily calibrated is proposed.

We describe several computer-implemented systems for automatic speech recognition. The systems are designed for specific communication tasks in which the human talker and machine interact in a disciplined dialog. One speaker-dependent system recognizes individual spoken words and provides information on airline flight schedules. The same system, combined with a programmed syntax analyzer, recognizes whole sentences that are chosen from a sub-set of natural English. Another system provides automated telephone directory assistance by recognizing voiced-spelled names and speaking back the requested telephone number. Still another system recognizes digits spoken by any speaker, and provides the capability for automatic voice dialing. All the speech recognition systems utilize dynamic programming to match spoken input with stored reference templates.

A recent advance in speech synthesis technology is the integration of a complete speech synthesizer onto a single integrated circuit. This chip is the basis for several low cost “talking” consumer products. Speech is synthesized from stored digital information extracted from actual speech signals. Memory requirements are approximately 1200 bits per second or 800 bits per word. This development offers the potential for including voice response into a wide variety of applications at a very low cost.

Voice data entry systems are achieving productive and effective results NOW. Although the future will provide many changes to this technology which will reduce the costs, make them easier to use, etc., many companies have taken advantage of what can be accomplished through practical approaches to their application requirements. Since nothing available today is fully perfected, those who wait for perfection are missing out on improving their operations and profits. Much can be learned by evaluating how voice data entry systems have been utilized by creative management personnel.

This paper describes an experimental approach to continuous speech recognition being carried out at IBM Research. It is based on statistical methods that allow automatic extraction of recognizer parameter values from speech data. Research results are presented for both artificial and natural recognition tasks.

A 100-kW automotive gas turbine is being investigated at Volkswagenwerk. The paper describes the special features of the component elements of this engine and presents the current status of engine development in regard to response time, fuel consumption, multi-fuel capability, and engine emissions. Test results are submitted of an experimental gas-turbine-powered vehicle. Reference is made to further fuel economy improvements with the aid of ceramic components.

Detroit Diesel Allison is developing ceramic hot flowpath components for application in small vehicular industrial gas turbine engines. A key element of this program is the development of an appropriate methodology for predicting component reliability. This paper discusses the elements of the established methodology and compares predicted and measured reliabilities of a blade attachment spin test coupon in order to assess the validity of analysis techniques. Included are summaries of methods used to obtain and analyse material strength characteristics, finite element modeling technique, blade coupon reliability computations, blade coupon spin test results and failure analyses.

Previously measured particulate mass concentrations from a single-cylinder indirect-injection diesel, obtained under conditions of both varying dilution ratio and varying filter temperature, are examined in detail. Considering the mechanisms of condensation, adsorption, and diffusion, the observed variations in total particulate mass are attributed primarily to the adsorption and desorption of exhaust hydrocarbons on the solid particulate matter. A simple Langmuir adsorption model is used to explain qualitatively the observed effects of dilution ratio and sample temperature. Only under conditions of relatively high hydrocarbon emission is the condensation mechanism also shown to be important. The simple adsorption analysis also predicts the trends observed in CVS (Constant Volume Sampling) dilution tunnels in which filter temperature and dilution ratio change simultaneously.

A dilution mini-tunnel is described that allows collection of diesel exhaust particulate samples with independent control of the dilution ratio and the sample filter temperature. This tunnel was used to determine the individual effects of these two tunnel operating variables on the samples collected from a single-cylinder indirect-injection test engine run at constant speed and load. Either increasing the filter temperature at fixed dilution ratio or increasing the dilution ratio at fixed filter temperature resulted in a decrease in total particulate mass. These changes in total mass were attributed to changes in the soluble fraction of the particulate sample.

Presence of soot in gas analysis systems is believed to cause errors in measurement of the concentration of oxides of nitrogen (NOx) because of adsorption of NOx by soot. The work reported herein involves a preliminary experimental and theoretical analysis to determine the extent of the errors caused by the interaction of NOx with soot suspended in diesel exhaust measurement systems. The experimental results, which are in qualitative agreement with the theory, suggest that at room temperature the percentage of NOx adsorbed by soot suspended in the exhaust Stream is a function of the residence time of the gas sample in the sample line. Therefore, a short sample line and a high flow rate would minimize the error in the measurement of NOx.

The accurate sampling and characterization of automotive particulate emissions is important to quantify any potential threat to human health. EPA has issued a draft recommended practice to measure the total weight of particulates emitted over the FTP, but there are many parameters that are uncontrolled or can be varied within the scope of the draft recommended practice. The parameters were separated into two categories: those affecting particulate formation and those affecting particulate sampling. The variables under the former category were identified as tailpipe conditioning and heat transfer, dilution ratio, and mixing rate. Test data on the effects of each of these variables on measured particulate emissions are presented and analyzed. The variables under the latter category were identified as the tunnel configuration, sample probe and sample line, and the type of filter used for sampling.

Knowledge of the deformation amplitude of the tire components during the actual running is important in the analysis of the fatigue process of the tire components. Attempts to imbed strain gauges in the tire carcass to measure the deformation met difficulties due to the alteration of carcass properties in the process of imbedding the strain gauges. In this article, we describe an attempt to estimate the tire deformation in operation from the data of temperature rise. Measurement of the temperature rise is considerably easier than the measurement of the deformation. The temperature data are analyzed by considering the dynamics of self-heating which includes the heat generation rate terms.

Estimating product life from laboratory or field test data is a frequently encountered problem. One popular approach to handling this problem is through the use of Weibull graph paper. However, the accuracy of prediction is difficult to determine, since it involves the engineer, the graph paper, and the statistical variability of the population. This paper presents the results of a study to determine the accuracy that can be expected in typical Weibull plotting and estimating situations. The study was based on designed experiments utilizing typical engineers to provide estimates. The results provide guidance in the selection of sample size and assessment of prediction accuracy.

A flat belt tire test machine is described which was designed to measure tire energy dissipation under conditions simulating a vehicle being driven over a sequence of EPA driving cycles. The machine has two tires loaded against each other across one span of a continuous steel belt running on steel drums. One of the tires is driven by a DC chopper controlled motor programmed to reproduce the speed history of the driving cycles. Tire force and speed voltage signals are multiplied in an analog multiplier and then integrated to find the energy passing into and out of the tires.

A history of the development of rubber material specifications for molded, extruded and lathe cut products is discussed. This includes the philosophies of the writing committes as well as the thought processes to arrive at SAEJ200 - ASTMD2000 classification of specifications. A continuing need for further continuous involvement by SAE is mentioned.

This paper presents the concept of gasified diesel fuel as a potential solution to the diesel engine emissions problem, especially the particulates. The concept employs two-stage combustion. During the first stage of combustion diesel fuel is partially oxidized with air in a catalytic reactor and converted to a hydrogen-rich gas. During the second stage of combustion the hydrogen-rich gas is mixed with additional air and burned to completion in the engine. The first stage reaction is catalytic and when carried out at an air-fuel mass ratio of 5.2, it does not produce soot or particulates. The subsequent combustion of the hydrogen-rich gas in the engine does not form soot or particulates. The conversion of diesel fuel to a hydrogen-rich gas is an exothermic reaction. The energy released during the process can be recovered in a Rankine engine heat recovery unit to prevent a net loss in fuel economy.

The octane rating and autoignition temperature of methanol-gasoline blends were measured. Large increases in autoignition temperature and ignition delay time were found for small percentages of added methanol. These increases correlated well with the increases in research octane rating throughout the range of blends. The evaporative cooling effect of the methanol was concluded to be the major mechanism suppressing detonation.

The concentrations of soot, NO and the other combustion products were measured by incylinder gas sampling in a DI diesel engine. The effects of injection timing, swirl ratio, and combustion chamber geometry on the formation and emission processes of soot and NO were studied. The following results were obtained: (1) Soot is promptly formed in the flame during the early combustion period where the equivalence ratio in the flame is high over 1.0. Thereafter almost all the formed soot is swiftly burnd up by oxidation during the middle combustion period. This process mainly determines the exhaust soot concentration. (2) NO is formed in the flame during the early and middle combustion period where the flame temperature is high over 2000 K. The highest NO concentration is observed at the flame tip swept by the air swirl. Though the concentration of the formed NO decreases by dilusion it nearly constant during the later combustion period.

A radioactive tracer technique was developed to determine the contribution of oil from an engine sump to exhaust particulate matter collected on a filter. The technique was applied to particulate emissions produced by an automotive diesel engine which was operated on an engine dynamometer over a range of steady-state conditions. The results indicated that from 1.5 to 25 mass percent of the particulate matter, depending on speed and load, consisted of material from the engine oil. The oil contribution to the extractable organic portion of the particulate matter ranged between 16 and 80 percent.