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High Efficiency IC Engines, 2012

2012-04-13
The 14 papers in this technical paper collection discuss high efficiency IC engines. Topics covered include engine downsizing, pressure boosting and turbocharging, intelligent combustion, low temperature and stratified charge, advanced fuel injection technologies, and more. The 15 papers in this technical paper collection discuss high efficiency IC engines. Topics covered include engine downsizing, pressure boosting and turbocharging, intelligent combustion, low temperature and stratified charge, advanced fuel injection technologies, and more.
Collection

Engine Boosting Systems, 2018

2018-04-03
The papers in this collection cover conceptual, modeling, and experimental studies relating to advanced turbochargers/superchargers and advanced boosting systems to achieve increased power density, better fuel economy, and reduced emissions.
Collection

Engine Boosting Systems, 2017

2017-03-28
The papers in this collection cover conceptual, modeling, and experimental studies relating to advanced turbochargers/superchargers and advanced boosting systems to achieve increased power density, better fuel economy, and reduced emissions.
Video

High Load HCCI Operation Using Different Valving Strategies in a Naturally-Aspirated Gasoline HCCI Engine

2012-02-16
This session focuses on kinetically controlled combustion. Experimental and simulation studies pertaining to various means of controlling combustion are welcome. Examples are research studies dealing with temperature and composition distribution inside the cylinder and their impact on heat release process. Studies clarifying the role of fuel physical and chemical properties in autoignition are also welcome. Presenter Hanho Yun, General Motors Company
Video

Spotlight on Design: Sensors: Miniaturization and Testing

2015-04-15
“Spotlight on Design” features video interviews and case study segments, focusing on the latest technology breakthroughs. Viewers are virtually taken to labs and research centers to learn how design engineers are enhancing product performance/reliability, reducing cost, improving quality, safety or environmental impact, and achieving regulatory compliance. Accurate data is critical for the testing and development of parts and systems for cars, trucks, and airplanes. To obtain this data, engineers rely on high-end specialty sensors that can fit into cramped spaces and operate reliably under extreme heat and pressure. In the episode “Sensors: Miniaturization and Testing” (21:02), AVL engineers explain how a new crystalline material was developed to accurately measure the high pressures in the combustion chamber of turbocharged engines, and Meggitt Sensing Systems profiles the world’s smallest triaxial IEPE accelerometer.
Video

Development of High-Efficiency Rotary Engines

2012-05-10
Combustion engines are typically only 20-30% efficient at part-load operating conditions, resulting in poor fuel economy on average. To address this, LiquidPiston has developed an improved thermodynamics cycle, called the High-Efficiency Hybrid Cycle (HEHC), which optimizes each process (stroke) of the engine operation, with the aim of maximizing fuel efficiency. The cycle consists of: 1) a high compression ratio; 2) constant-volume combustion, and 3) over-expansion. At a modest compression ratio of 18:1, this cycle offers an ideal thermodynamic efficiency of 74%. To embody the HEHC cycle, LiquidPiston has developed two very different rotary engine architectures ? called the ?M? and ?X? engines. These rotary engine architectures offer flexibility in executing the thermodynamics cycle, and also result in a very compact package. In this talk, I will present recent results in the development of the LiquidPiston engines. The company is currently testing 20 and 40 HP versions of the ?M?
Technical Paper

Analytical Prediction of Acoustic Emissions From Turbocharger Bearings

2020-09-30
2020-01-1504
Turbochargers are progressively used in modern automotive engines to enhance engine performance and reduce energy loss and adverse emissions. Use of turbochargers along with other modern technologies has enabled development of significantly downsized internal combustion engines. However, turbochargers are major sources of acoustic emissions in modern automobiles. Their acoustics has a distinctive signature, originating from fluid-structure interactions. The bearing systems of turbochargers also constitute an important noise source. In this case, the acoustic emissions can mainly be attributed to hydrodynamic pressure fluctuations of the lubricant film. The developed analytical model determines the lubricant pressure distribution in the floating journal bearings used mainly in the modern turbocharges. This allows for an estimation of acoustic emissions.
Technical Paper

Modelling and Numerical Simulation of the Noise Generated by Automotive Turbocharger Compressor

2020-09-30
2020-01-1512
An effective technology to reduce emission and fuel-consumption is the use of turbochargers. A turbocharger increases the air pressure at the inlet manifold of the engine by using the waste energy from the exhaust gas to drive a turbine wheel that is linked to the compressor through a shaft. Besides the use in combustion engines, fuel cell systems for vehicle applications also need compressed air to achieve high power densities. Thereby, in fuel cell systems the noise emission of turbochargers is no longer masked by the combustion engine. In operation, the main noise sources are generated by the flow in the compressor and the different noise phenomena need to be understood in order to efficiently reduce the emitted noise and increase comfort. A huge potential in order to achieve this goal is a simulation based investigation to study in detail the flow mechanism, the aeroacoustic sources and its sound propagation.
Book

Design of Racing and High Performance Engines

1995-02-01
This book presents, in a clear and easy-to-understand manner, the basic principles involved in the design of high performance engines. Editor Joseph Harralson first compiled this collection of papers for an internal combustion engine design course he teaches at the California State University of Sacramento. Topics covered include: engine friction and output; design of high performance cylinder heads; multi-cylinder motorcycle racing engines; valve timing and how it effects performance; computer modeling of valve spring and valve train dynamics; correlation between valve size and engine operating speed; how flow bench testing is used to improve engine performance; and lean combustion. In addition, two papers of historical interest are included, detailing the design and development of the Ford D.O.H.C. competition engine and the coventry climax racing engine.
Technical Paper

Power Brakes for Passenger-Cars

1928-01-01
280017
THE use of a power medium in brake control points at once to the possibility of simplifying the brake system so that its characteristics, once established, can be expected to remain uniformly effective throughout extended periods without adjusting, with correspondingly long life of brake-linings. The author says also that, if the greater retarding effect possible with mechanically operated four-wheel brakes is to be fully realized, it is necessary to do one of three things: increase the pedal pressure, increase the brake leverage and consequently the pedal movement, or increase the “self-energizing” effect. The vacuum-type brake described is stated to be an amplifier which provides power to supplement muscular strength and assists the driver to apply the service brake, thereby reducing the required pedal stroke and pedal pressure without interfering with the regular service-brake hook-up.
Technical Paper

Data on Machinability and Wear of Cast Iron

1928-01-01
280022
THE hardness or chemical composition of an iron is, by itself, no indication of the wearing property and machinability of the iron. Irons containing a large amount of free ferrite have been found to wear rapidly, whereas others having considerable pearlite or sorbite in their structure show good wearing properties. The presence in cylinder-blocks of excess-carbide spots or of phosphides of high phosphorus-content is deleterious, because such spots wear in relief and the material ultimately breaks out, acting as an abrasive that scores the surfaces. Causes of wear in cylinder-blocks are discussed, and nickel, or nickel and chromium, intelligently added to the iron is suggested as a means of obtaining the correct microstructure for a combination of good wearing properties and machinability.
Technical Paper

The Influence of Fuel Characteristics on Engine Acceleration

1928-01-01
280043
SELECTION of a method and development of apparatus enabling precise and detailed measurement of engine acceleration is discussed in the first portion of this paper, the latter portion of which is concerned with the experimental results thereby obtained. Previous work on the influence of engine conditions on acceleration is generally substantiated. A method is described for approximately deriving the effective air-fuel ratio delivered to the cylinders during acceleration, practical applications are suggested, and limitations are discussed. The effect of fuel volatility on engine acceleration was studied, using six fuels: Aviation gasoline; commercial gasoline; a blend composed of equal parts of the two; and three especially prepared fuels, all of which have equal 20 and 90-per cent points but differ widely at the 50-per cent point. It is shown that the relative values of these fuels for acceleration depend upon the amount of vaporization in the manifold.
Technical Paper

Performance of a Supercharged Passenger-Car

1928-01-01
280041
A STUDY of the effect of supercharging on the performance of the engines of passenger-cars showed that the power increase varied from 35 per cent at 1000 r.p.m. to 59 per cent at 3000 r.p.m., with a maximum supercharging pressure of only 6.5 lb. per sq. in. In acceleration tests made at the General Motors Proving Ground of two cars of similar model, one equipped with a supercharged engine and the other with a high-compression engine, the supercharged car accelerated from 5 to 25 m.p.h. in 5 sec.; the unsupercharged car, in 10 sec. From 15 to 50 m.p.h. the supercharged car accelerated in 12.7 sec.; the unsupercharged car, in 21.0 sec. On an 11-per cent grade up which the cars were started at 10 m.p.h., the speed of the supercharged car was 40 m.p.h. at the top; that of the unsupercharged car was 18 m.p.h. These and other results of the tests are portrayed by curves.
Technical Paper

Front-Wheel Drives, Are They Coming or Going?

1928-01-01
280036
AFTER listing the advantages and disadvantages of front-wheel drive the author says that, although most American engineers who have given him their opinions seem to believe that the advantages of front-wheel drive are outweighed by its disadvantages, he has grounds for venturing the opinion that this form of drive is likely to have extensive use in this Country within the next few years. He bases this view more upon commercial than upon strictly engineering considerations; but the latter are not lacking altogether, as is evident from his subsequent analysis. The advantages and the disadvantages are specifically and separately discussed, existing designs of front-wheel drive being divided into three classes. Numerous illustrations of the different types of front-wheel-drive vehicle are presented, and their most important features are enumerated and explained.
Technical Paper

High-Speed High-Efficiency Engines

1928-01-01
280039
MARKED improvement in high-speed high-efficiency engines will be accomplished during the next few years, according to the author. They will have better balance, longer life and greater efficiency, and will develop more power and be more satisfactory to the motoring public. Details of recent developments in this class of engine are given by the author after remarking that the present trend is toward a large number of small changes in design and construction rather than toward radical departures from former design and methods. Mr. Duesenberg comments upon the main features of design of his 91-cu. in. racing-car engine and its parts, and on the troubles that necessitated design changes. The combustion-chamber is stated to be the most important contributor to high efficiency. If the shape of the combustion-chamber, the area of the valves, and the location of the valves and spark-plugs are not right, all the other refinements of detail are of little value.
Technical Paper

The Application of Superchargers to Automotive Vehicles

1928-01-01
280040
MOST passenger automobiles are overpowered and probably 80 per cent of such vehicles operate at less than 35 m.p.h. for 90 per cent of the time, according to the author. At 30 m.p.h. an average 3000 to 3500-lb. passenger-car requires from 12 to 15 hp., but the engine carried is capable of developing from 50 to 55 hp. The result is that the car is operated for the greater part of the time at one-third to one-quarter throttle opening. Full power is needed only for accelerating and hill-climbing; during the remainder of the time the excess weight of the engine and other parts must be carried at a loss of efficiency. The author maintains that smaller engines can be used advantageously when equipped with superchargers, the supercharger being used only when excess power is required.
Technical Paper

Automobile Practice in Europe

1928-01-01
280037
EUROPEAN trends in some of the major features of engine, chassis and body design and in several items of equipment are reviewed in this paper; which is based on the observation and analysis of the British engineer editor who is its author, and of the staff of The Motor, of London, during the last five years. Although American automotive engineers who follow European practice are acquainted with most of the designs here shown and described briefly, this paper is of interest and value as showing the present principal lines along which development is taking place abroad. Popular chassis types are divided into three classes: (a) the “baby” four-cylinder car of 7 to 9 hp., Royal Automobile Club rating; (b) the “family-type” four-cylinder car of 12 to 14-hp. rating; and (c) the light six-cylinder car of 15 to 20-hp. rating. Typical acceleration curves for well-known cars in each of these classes are given, as well as cylinder dimensions, volumetric capacity, car weight and price.
Technical Paper

Progress in Honing-Machines and the Honing Process

1928-01-01
280060
CYLINDER finishing by rough and finish-boring with wide tools, which was thought good enough during the first dozen years of the automobile-production period, was supplanted by reaming and grinding. Later, cast-iron and copper laps were used, but all these methods were slow and did not produce the fine finish for which a demand developed. Experiments were begun about 1920 with the process known as honing. Five years later the company with which the author is connected converted one of its drilling-machines into a single-spindle honing-machine. Other companies made similar conversions. The first honing-head was introduced in 1923. Not until three years ago, however, did honing begin to be regarded as a real production-method possibility. Since then, very rapid progress has been made and numerous improved machines, honing-heads and honing-stones have been produced.
Technical Paper

Automobile Induction-Systems and Air-Cleaners

1928-01-01
280051
AFTER indicating the trend of requirements in induction systems, the author discusses air-cleaners, carbureters and inlet manifolds. Particular attention is paid to improvements in centrifugal air-cleaners, that result in only slight pressure loss and in high cleaning efficiency. These improvements have been made by changing the body outline; by the addition of a diffuser, to make the resistance as small as possible; and by proportioning the vanes, as to angle and number, to increase the cleaning efficiency with only slight loss in pressure. Carbureters are considered briefly, only because of their interrelation with air-cleaners and manifolds. Inlet manifolding for four, six, and eight-cylinder-inline engines is studied, with variations in port arrangement. Recommendations are made as to the cross-sectional areas and form to secure best distribution of the mixture and adequate vaporization.
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