Refine Your Search



Search Results

Technical Paper

Design Features of the JUNKERS 211B AIRCRAFT ENGINE

THE Junkers 211B engine follows the usual German practice of very large displacements and conservative mean effective pressures and rotative speeds. However, the relative light weight per unit of displacement results in a net weight per horsepower that is not far above its competitors. Fully automatic devices which control propeller speed, manifold pressure, mixture ratio, spark advance, and supercharger gear ratio follow the German policy of removing all possible distractions from the pilot. This is one of three large liquid-cooled engines known to be produced in quantity in Germany; it powers an impressive percentage of the Luftwaffe. While of external appearance and displacement that resemble the Daimler-Benz DB-601 engine, the fundamental construction, detail design practice, and metallurgy of the Junkers 211B are surprisingly different.
Technical Paper

Predicting ROAD PERFORMANCE of Commercial Vehicles

A SIMPLE method of predicting truck performance in terms of grade ability at a given road speed, taking into consideration rolling resistance, air resistance, and chassis friction is presented here. A brief review of fundamental considerations is given first, then the method recommended for predicting vehicle ability at a selected speed, and finally a few words on the prediction of maximum possible road speed and selection of gear ratios. The basis of the solution is the determination and expression of vehicle resistances in terms of horsepower - that is, in terms of forces acting at a velocity. A convenient method of solving the grade problem at a given speed is by means of a tabular computation sheet, which is given, together with tables and charts. These assist in making the computation an easy one as well as giving the necessary data on vehicle resistances.
Technical Paper

The New PLYMOUTH Engine

PLYMOUTH'S new V-8 engine has a specific output of 0.65 bhp/cu in. and 145-psi bmep — obtained through a combination of high thermal, volumetric, and mechanical efficiencies. Good design, the author points out, has achieved this high output despite the dual-venturi carburetor and the 7.6/1 compression ratio, selected for satisfactory operation on regular-grade fuels. The engine has a bore and stroke of 3.563 × 3¼, weighs 568 lb without flywheel, is 29⅜ in. long, and is designed for optimum response to future compression ratio increases. (A report of oral discussion following presentation of this paper appears on p. 220, following “The New Packard V-8 Engine,” by W. E. Schwieder.)
Technical Paper

Considerations Affecting the Life of Automotive Camshafts and Tappets

WORK done in a development program relative to camshafts and tappets in the design of the Chrysler overhead-valve V-8 engine is described. The types of failure encountered are categorized as wear, scuffing, and fatigue. An accelerated test procedure was designed to promote early cam-tappet failures, and the development work was predicated upon the results obtained therefrom. Among the variables affecting the failure conditions, major emphasis was placed on material development. Specifically, the greater amount of time was spent in determining the optimum tappet material, while some time was devoted to the camshaft material. A combination of adjusted chemical composition and heat-treatment of hardenable cast iron for camshaft and tappets provided the best solution to the failure problems.
Technical Paper

Development Highlights and Unique Features of New Chrysler V-8 Engine

THE design and development of the new valve-in-head V-8 Chrysler engine of 7.5 compression ratio are described here. Among the features discussed by the authors are: the hemispherical combustion chamber, V-8 cylinder arrangement, double-breaker distributor, “thermal flywheel” on automatic choke, and exhaust-heated and water-jacketed throttle bodies. The hemispherical combustion chamber was adopted after it had displayed excellent volumetric and indicated thermal efficiencies, and an ability to maintain these high efficiencies in service. The high volumetric efficiency, for example, is considered to be due to such design features as valves not crowded together, nor surrounded closely by the combustion-chamber walls. They are thereby fully effective in the flow of the fuel-air mixture and the exhaust gases. The authors also present performance data for this engine, which, at full throttle, develops 180 hp at 4000 rpm and 312 ft-lb of torque at 2000 rpm.
Technical Paper


THIS paper explains a few of the basic principles of the character of sound and the mechanism of human hearing. The author describes some simple experiments which demonstrate the relationship between intensity and loudness and the nature of harmony. He also points out the difficulties of accurately analyzing sound electronically, and the resulting importance of combining the finest electronic equipment with sharp, attentive human faculties. Five basic ways to reduce noise and the mechanics of each are described. The effect of these methods on the work of the sound engineer is indicated.
Technical Paper

Application of Design and Development Techniques for Direct Injection Spark Ignition Engines

Gasoline direct injection technology is receiving increased attention among automotive engineers due to its high potential to reach future emission and fuel economy goals. This paper reports some of the design and development techniques in use at Chrysler as applied to four-stroke Direct Injection Spark Ignition (DISI) engines. The spray characteristics of Chrysler's single-fluid high-pressure injector are reported. Tools used in the design process are identified. Observations of the in-cylinder fuel/air mixing process using laser diagnostic techniques and Computational Fluid Dynamics (CFD) are described. Finally, combustion and emissions characteristics using Design of Experiment (DoE) tests are presented.
Technical Paper

Effect of Valve-Cam Ramps on Valve Train Dynamics

Testing of an OHC valve train with hydraulic lash adjuster in which the valve displacements, velocities and accelerations were measured and analyzed in both time and frequency domains, coupled with analysis of the frequency content of the valve acceleration function and its ramps, show that traditional designs of the opening and closing ramps used on some IC engine valve cams can exacerbate vibration in the follower system causing higher levels of spring surge and noise. Suggestions are made for improvement to the design of the beginning and ending transitions of valve motion which can potentially reduce dynamic oscillation and vibration in the follower train.
Technical Paper

The Application of Graphics Engineering to Gear Design

A highly competitive market and increased emphasis on quality have gear designers searching for additional tools to produce accurate gearsets in a condensed timeframe. To meet this challenge, a Graphics Engineering method has been developed to enhance traditional gear design techniques. Graphics Engineering links interactive graphics, finite element analysis and solid modeling into a graphics/analysis development package. Starting with gear and cutter data derived by conventional techniques, it provides cutter paths and involute profiles for geometry, strength, and physical property analysis. The comprehensive data obtained through Graphics Engineering provides a powerful tool for the gear designer to increase gearset accuracy and reduce design iterations.
Technical Paper

Can the k-ε Model Withstand the Challenges Posed by Complex Industrial Flows?

The purpose of this paper is to present numerical solution for three-dimensional flow about rotating short cylinders using the computer program AIRFLO3D. The flow Reynolds number was kept at 106 for all computations. The drag forces on the cylinder were obtained for different rotational speeds. Predictions were obtained for both an isolated cylinder and a cylinder on a moving ground. The standard k-ε model was employed to model the turbulence. Computed drag coefficients agreed well with the previous experimental data up to a spin ratio (=rω/V) of 1.5.
Technical Paper

An Evaluation of Turbulent Kinetic Energy for the In-Cylinder Flow of a Four-Valve 3.5L SI Engine Using 3-D LDV Measurements

A better understanding of turbulent kinetic energy is important for improvement of fuel-air mixing, which can lead to lower emissions and reduced fuel consumption. An in-cylinder flow study was conducted using 1548 Laser Doppler Velocimetry (LDV) measurements inside one cylinder of a 3.5L four-valve engine. The measurement method, which simultaneously collects three-dimensional velocity data through a quartz cylinder, allowed a volumetric evaluation of turbulent kinetic energy (TKE) inside an automotive engine. The results were animated on a UNIX workstation, using a 3D wireframe model. The data visualization software allowed the computation of TKE isosurfaces, and identified regions of higher turbulence within the cylinder. The mean velocity fields created complex flow patterns with symmetries about the center plane between the two intake valves. High levels of TKE were found in regions of high shear flow, attributed to the collisions of intake flows.
Technical Paper

Statistical Decision Making in FMVSS Testing

This paper presents a method of accounting for sample variability and sample size in establishing the acceptable bogey levels. The technique makes use of the statistical tolerance theory which accounts for the variability of the sample mean and standard deviation by determining a K-factor adjusted for sample size. The result is a tolerance that is reasonably assumed to cover a specified fraction of the population of parts. The technique, although not as simple as a fixed bogey, does discriminate between designs with different levels of energy management robustness.
Technical Paper

Application of Induction Heating in Automotive Production

INDUCTION heating is a process or method by which metal parts are heated by simply placing them in an alternating magnetic field. The action is that of the transformer, whereby electrical energy is transferred or passed over to another isolated electric or secondary circuit by means of the magnetic field; thus, no physical attachments or electrical contacts are necessary to have electrical currents, which are dissipated as heat, flow in the parts to be processed. The strength and frequency of the alternating magnetic field can be selected to produce any desired rate of heating and ultimate temperature. A circuit can be set up to dry lacquer at 160 deg. fahr. on thin sheet-metal parts or to melt in record time immense steel ingots. Induction heating is now commercially applied in automotive production to many processes, and these are specified.
Technical Paper

Fuel Mixture Temperature Variations in the Intake Port

Temperature variation and heat transfer phenomena in the intake port of a spark ignition engine with port injection play a significant role in the mixture preparation process, especially during the warm up period. Cold temperatures in the intake port result in a large amount of liquid-fuel film. Since the liquid-fuel film responds at a slower speed than the gas-phase flow during transient operations, the liquid-fuel film acts as a fuel sink (or source) and can degrade the vehicle's driveability, fuel economy, and emissions control. In this work, a one-dimensional, unsteady, multicomponent, multiphase flow model has been developed to study the mixture formation process in the intake port for a modern, multipoint-fuel-injection, gasoline engine. The droplet, liquid film and gas-phase mixture temperature variations and the effects of charge air, initial fuel and port wall temperatures involved in generating the air-fuel mixture are examined.
Technical Paper

Changes in Reliability During the Design and Development Process of a Vehicle's Electrical/Electronic Systems

The changes in reliability of the Electrical/Electronic Systems of a vehicle-line during its early design and development engineering processes have been studied. A computerized vehicle failure tracking system was used to provide results from several stages of early development vehicle testing at the proving grounds. The data were analyzed using a software program that assumes that failures in a repairable system, such as a car, occur as a nonhomogeneous Poisson process. Results suggest that, under normal circumstances, a significant and quantitative improvement in reliability is achievable as the system or component design progresses through the early design and development processes. This also provides a means of predicting future system(s) reliability when the system(s) is in production.
Technical Paper

Experimental and Computer Simulation Analysis of Transients on an Automobile Communication Bus

Voltage and current surges are a major concern when it comes to ensuring the functional integrity of electrical and electronic components and modules in an automobile system. This paper presents a computer simulation study for analyzing the effect of high voltage spikes and current load dump on a new Integrated Driver/Receiver (IDR) IC, currently being developed for a J1850 Data Communication Bus in an automobile. It describes the modeling and simulation of the protection structure proposed for the device. The simulation study yields a prediction of current and voltage capability of the protection circuit based on thermal breakdown and transient responses of the circuit. Two levels of modeling, namely, the behavioral level model and the component level model, are used to generate the simulation results. Experimental data will be acquired and used to validate the simulation model when the actual device becomes available.
Technical Paper

Network I/O and System Considerations

The J1850 bus requirements promote an unique and well characterized physical layer behavior developed through the learning curve of previous multiplex solutions. Design requirements such as: 1) Reliably interconnecting all of the vehicle's most complex modules, 2) Consistently withstanding the vehicle's harsh environment, and 3) Meeting SAE's functionality requirements, were all a formidable task to achieve. This paper will highlight the path taken to achieve a J1850 Bus interface which successfully met all of the design and functional goals. Chrysler's C2D insights will be discussed and related to goals for J1850. Other design considerations will also be discussed such as EMC issues, custom test equipment, and vehicle and component testability. In turn, silicon processes with special structures and topologies will be discussed relating the specific design with the needed electrical behavior. The HIP7020 J1850 BUS TRANSCEIVER I/O for MULTIPLEX WIRING accomplishes these requirements.
Technical Paper

OPNET J1850 Network Simulator

MIL 3's OPNET simulator was used to model Chrysler's J1850 bus. Modeled were both J1850 bus characteristics and those portions of control modules (e.g., the engine controller) which communicate on the bus. Current Chrysler control module algorithms and proposed Chrysler J1850 message formats were used to design the control module models. The control module models include all messages which are transmitted at fixed intervals over the J1850 bus. The effects of function-based messages (e.g., messages to be transmitted on a particular sensor or push-button reading) on system load were investigated by transmitting an additional message with a fixed, relatively high priority at 50 millisecond intervals.
Technical Paper

Architecture and Operation of the HIP7010 J1850 Byte-Level Interface Circuit

As a cost effective solution to making microcontroller based systems “J1850[1] aware”, a peripheral device (the HIP7010) was developed to extend the capabilities of standard microcontrollers. From the perspective of the Host, the peripheral device handles J1850 messages as a series of bytes (similar in concept to a universal asynchronous receiver/transmitter [UART]). The architecture of the HIP7010 is discussed. The design of the J1850 interface, state machine, status/control blocks, cyclical redundancy check (CRC) hardware, host interface, and fail-safe features are detailed. Illustrations are provided of: Host/HIP7010 interfacing; message transmission and reception; error handling; and In-Frame Response (IFR) generation.