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Training / Education

Ignition Issues and Their Impact on Engine Performance, Efficiency and Emission

Improved understanding and control of ignition and thereby combustion are critical in dealing with the problems of pollutants formation, engine performance, and fuel economy. This seminar will provide you with basic knowledge and recent advances in combustion-initiation (ignition) issues to more intelligently evaluate and harness their potentials. Thermodynamic and fluid mechanical properties of the unburned charge near the spark plug and at the time of ignition strongly affect the quality of the combustion and therefore the emission of the pollutants from the engine. Furthermore, a weak ignition limits engine performance and drivability.
Training / Education

Introduction to Commercial and Off-Road Vehicle Cooling Airflow Systems

Vehicle functional requirements, emission regulations, and thermal limits all have a direct impact on the design of a powertrain cooling airflow system. Given the expected increase in emission-related heat rejection, suppliers and vehicle manufacturers must work together as partners in the design, selection, and packaging of cooling system components. An understanding and appreciation of airflow integration issues and vehicle-level trade-offs that effect system performance are important to the team effort. The severe duty cycles, minimal ram air, and sometimes unconventional package layouts present unique challenges.
Training / Education

The Basics of Internal Combustion Engines

In your profession, an educated understanding of internal combustion engines is required, not optional. This two-day technology survey seminar covers the most relevant topics - ranging from the chemistry of combustion to the kinematics of internal components of the modern internal combustion engine - for maximum comprehension. Attendees will gain a practical, hands-on approach to the basics of the most common designs of internal combustion engines, as they apply to the gaseous cycles, thermodynamics and heat transfer to the major components, and the design theories that embody these concepts.
Training / Education

Turbocharging Internal Combustion Engines

The need to control emissions and maintain fuel economy is driving the use of advanced turbocharging technology in both diesel and gasoline engines. As the use of diesel engines in passenger car gasoline and diesel engines increases, a greater focus on advanced turbocharging technology is emerging in an effort to reap the benefits obtained from turbocharging and engine downsizing. This seminar covers the basic concepts of turbocharging of gasoline and diesel engines (light and heavy duty), including turbocharger matching and charge air and EGR cooling, as well as associated controls.
Training / Education

Control Systems Simplified

The advent of digital computers and the availability of ever cheaper and faster micro processors have brought a tremendous amount of control system applications to the automotive industry in the last two decades. From engine and transmission systems, to virtually all chassis subsystems (brakes, suspensions, and steering), some level of computer control is present. Control systems theory is also being applied to comfort systems such as climate control and safety systems such as cruise control or collision mitigation systems.
Training / Education

Fundamentals of Powertrain Design for Hybrid Electric Vehicles

This course is offered only in China. Driven by high fuel prices, environmental regulations, and consumer demand, the market for hybrid electric vehicles (HEV) has experienced rapid growth. Every major automotive company produces an HEV. There are approximately fifty different HEV models on the market and over eight million HEVs already sold. In order to meet current and future demands in the HEV and PHEV markets, success will depend on engineering personnel knowing how to develop and manufacture HEV powertrains. This two day seminar will cover the fundamentals of HEV powertrain design.
Training / Education

The Principles and Applications of Powertrain Controls for the New Energy Vehicles

课程概述 Powertrain controls for NEVs is one of the most complex and highly confidential areas of NEV research and development. This two-day course takes the seemingly complicated field of NEV powertrain controls and summarizes it into a few basic principles. The latest and most popular NEV powertrains are also reviewed to illustrate these principles and the controls strategies used. 对于新能源汽车来说,动力总成控制一直以来都是最复杂的和高度机密的领域之一。在这两天的课程中,我们将把看似复杂的动力总成控制系统总结出几条基本规则,同时,通过对当今其他车型动力控制系统的案例分析,来把这些规则和原理进行融会贯通。
Technical Paper

Electrically Propelled Vehicles at BMW - Experience to Date and Development Trends

1991-02-01
910245
Back in the first two decades of automobile development, electric propulsion was a serious competitor for the internal combustion engine. Electrically-propelled vehicles, however, soon proved unable to satisfy users' increasing performance demands in terms of range, acceleration, top speed and hill-climbing, together with such factors as operating life, initial purchase price, running costs and reliability. Engineers investigating electric propulsion today face precisely the same unwelcome legacy as their predecessors, despite many and varied attempts in the meantime to improve the components of the electric vehicle's drive system (energy storage device, motors, controller). Progress in battery development, particularly in the case of the NaS system, has nevertheless enabled us at least partly to overcome the previous problems associated with electric drive systems, though it cannot be claimed that all obstacles to its commercial application have been eliminated as yet.
Technical Paper

Calculation of Inhomogeneous-Charge Combustion in a Swirl-Assisted Lean-Burn Engine

1991-02-01
910266
A multidimensional computational method is extended to include the methodology for modelling of partially-mixed inhomogeneous charge combustion and is applied to investigation of combustion and simultaneous mixing process of an inhomogeneous mixture in a lean-burn spark-ignition engine. The in-cylinder flow and charge mixture distribution pertain to a helical intake port with manifold fuel injection, and were obtained through complete simulation of the induction and compression processes. The engine compression ratio is 12:1 and the study pertains to the operating condition of 2500 rpm. The results show that the flow and charge distribution at the time of ignition is predominantly characterised by the evolution of the induction flow. The effect of heat release on enhancement of charge mixing is marginal and the pre-ignition charge distribution is preserved throughout the combustion.
Technical Paper

The Use of Intake and Exhaust Measurements with Computer Simulations to Investigate the Evolution of the Internal Flow Field in a Ported Engine

1991-02-01
910262
Recent measurements by of gas intake flows and exhaust pressure in a motored, ported, single-cylinder engine with strong swirl and roll have been used as boundary conditions to a three-dimensional, transient computer simulation of the flow within the cylinder. For each condition, the calculation is continued over several engine cycles until the periodic solution is obtained. The computed TDC tangential velocity and turbulence intensity are then compared with measured ones. A technique is described to evaluate scavenging efficiency, the fraction of charge that remains in the cylinder over later cycles and the degree of mixedness of fresh and residual charge. For this motored ported engine, it is found that the scavenging efficiency is very low (19.4% at 1200 RPM) and the inflow from the exhaust ports is very significant. For practical ported engines with combustion, the scavenging efficiency is much higher but the inflows from exhaust ports are still expected to be significant.
Technical Paper

Study of Swirl Effects on Spray Formations in D.I. Engines by 3D Numerical Calculations

1991-02-01
910264
Spray formations of three injection directions against swirl have been investigated by means of 3D numerical calculation, in-cylinder measurement, and engine performances tests. A direct injection type engine which has a single hole nozzle and a spark plug, has been operated, and three injection directions; a forward (same) direction, a reverse one, and a right-angled (central) one against a swirl direction, have been selected. Three types of intake port, futhermore, have been selected owing to create three types of in-cylinder flow, low swirl, middle swirl, and high swirl. Spray formations in 3D cylinder flow have been investigated by using a ‘KIVA’ code. Initial conditions of in-cylinder flow are based on data which have been measured in three dimensional by a LDV system under a motoring operation. Analysis results of spray formations by numerical calculations can explain well data of engine performance tests qualitatively, and some interesting results have been obtained.
Technical Paper

Numerical Simulation of Swirling Port-Valve-Cylinder Flow in Diesel Engines

1991-02-01
910263
A CAD/CAE procedure has been used for the analysis of the flow in an intake port-valve-cylinder assembly of a DI Diesel engine. The flow was simulated for both, steady state conditions and transient motored situation during intake and compression strokes. The characteristics of the helical port are analyzed, for the steady state case, in terms flow rate, generation of angular momentum flux and induced in-cylinder flow motion. The results of the simulation were correlated with experimental results, consisting of oil film visualizations on valve and intake port surfaces, and of local velocity measurements in the cylinder. The transient flow simulation shows the different characteristics of the flow motion in cylinder and piston bowl during intake and compression strokes. It was observed that the swirl generating capacity of the valve is different between the valve opening and closing phases.
Technical Paper

Stratification of Swirl Intensity in the Axial Direction for Control of Turbulence Generation During the Compression Stroke

1991-02-01
910261
Control of turbulence during the compression stroke is suggested by both theoretical calculations and experimental results obtained with an LDV measurement in a motored engine. The authors have found experimentally that when an axial distribution of swirl intensity exists, a large-scale annular vortex is formed inside the cylinder during the compression stroke and this vortex generates and transports turbulence energy. A numerical calculation is adopted to elucidate this phenomenon. Then, an axial stratification of swirl intensity is found to generate a large-scale annular vortex during the compression stroke by an interaction between the piston motion and the axial pressure gradient. The initial swirl profile is parametrically varied to assess its effect on the turbulence parameters. Among calculated results, turbulence energy is enhanced strongest when the swirl intensity is highest at the piston top surface and lowest at the bottom surface of the cylinder head.
Technical Paper

Compressible Turbulence Predicted by Reynolds Stress Models

1991-02-01
910260
Turbulence in strongly compressible flows as found in internal combustion engines is investigated with several models of turbulence. The standard k - ϵ model, 2 classical and 4 of the most recent Reynolds Stress models are used in this investigation. The compressible flow with a non-zero velocity divergence necessitates some changes to the incompressible model formulations normally presented. Flows selected for the present study are the spherical, radial and the uniaxial compressions/expansions belonging to the class of flows with irrotational normal strains. For the selected flows the response of the scalar quantities k and ϵ together with the anisotropy in the normal Reynolds stresses are examined. The initial behavior of isotropic turbulence in the rapid distortion theory (RDT) limit is a variation of k and ϵ as density to the power 2/3 and 4/3, respectively.
Technical Paper

An Adaptive Engine Control Algorithm for Acceleration Response

1991-02-01
910256
Chassis back and forth oscillation caused by sudden engine torque increase tends to occur, according to the characteristic of vehicle dynamics. This oscillation is called an acceleration surge and gives a vehicle driver a feeling of discomfort. This paper provides two control methods which can change the characteristic of vehicle acceleration response in order to suppress acceleration surge and to macth with driver's preference. The first control method is an acceleration servo method which is composed of control reference model and ignition timing control. The second control method is a variable response characteristic control algorithm. We treat the controlled object as the second order model with time delay, and assign the characteristic roots of transfer function in order to obtain the desired response.
Technical Paper

Control System for a Low Emissions Natural Gas Engine for Urban Vehicles

1991-02-01
910255
Natural gas has been the subject of growing interest as a low emissions alternative to conventional automotive engine fuels. The development of a control system for a very low emissions heavy-duty natural gas engine is described. The engine is intended for city bus applications, with emissions targets set well within US 1994 levels. The engine uses a stoichiometric air-fuel mixture with exhaust gas recirculation and a three-way catalyst. The control system was implemented on a prototype hardware architecture designed to facilitate algorithm development. The control system software was constructed from a number of fundamental modules. Good steady-state and transient air-fuel ratio control was particularly important for maintaining optimum catalyst efficiency and hence minimum emissions. To achieve this, the air-fuel ratio control system used solenoid gas injectors and lambda feedback.
Technical Paper

Applications of High Performance P/M Aluminum in Internal Combustion Engines

1991-02-01
910156
Powder Metallurgy (P/M) renders the possibilities to tailor material properties using rapid solidification or mechanical alloying processes totally different to the options of ingot metallurgy (I/M). For demanding applications in internal combustion engines new materials have become more important because of environmental and/or performance reasons. Weight reductions to improve the performance or reduce the consumptions and consequently the amount of exhaust gases and increase of temperatures at different locations of an engine need better aluminum materials. P/M solutions are described from the point of view of material's processing and general properties. The potential for automotive pistons is discussed with several examples.
Technical Paper

Cost Effective Finishing of Powder Forged Connecting Rods with the Fracture-Splitting-Method

1991-02-01
910157
The powder forging process closes the gap between conventional powder metallurgy and die forgings. Adequate shape of the preform and strict respect of its given volume avoids forging burrs and delivers closer tolerances. Powder Forging achieves higher density and therefore remarkably improved mechanical properties as compared to the conventional PM process. An example of application for a component with high dynamic stresses is the connecting rod. High precision and low weight tolerances already lead to less machining operations on sinterforged connecting rods than on classical forged or cast components. Using the patented KREBSÖGE fracture splitting procedure, subsequent costly machining operations become obsolete. This leads to remarkably lower investments for new machining lines and to cost savings for production.
Technical Paper

A Study of Oil Flow and Temperature in Journal Bearings

1991-02-01
910160
With the recent trend toward increased unit load in engine bearings, problems due to lack of lubrication frequently arise, especially in crankpin bearings. We have previously investigated the influence of shaft and bearing design on the oil flow using the connecting rod in actual use under alternating loads. In this paper, we investigate the critical value of oil flow at which the Fbearing temperature rises rapidly and the influence of connecting rod rigidity on the oil flow. As a result of these tests, it was discovered that the increase in bearing temperature (ΔTj) is in inverse proportion to oil flow (Qj),tests resulting in a single curve expressed by ΔTj = E1/Qj + E2, that the critical oil flow (Qc) varies according to Qc = Const. • E1, and that connecting rod rigidity greatly influences the oil flow (specifically, the greater the rigidity, the less oil).
Technical Paper

Application of a High Flexible Electronic Injection System to a Heavy Duty Diesel Engine

1991-02-01
910184
Future strict emission standards such as US 94 and EEC 96 for heavy duty diesel engines require injection systems more and more flexible. They have to be able to electronically control fueling, timing, and injection pressure as independent parameters. To be optimal this fuel injection equipment (F.I.E.) must be able to allow injection rate flexibility, separated pilot injection and cylinder cut-off. The F.I.E. from Nippondenso designated ECD-U2 offers all these characteristics. This paper deals with the installation and the application of this F.I.E. to a “RENAULT Véhicules Industriels” (R.V.I.) turbocharged and intercooled engine such as the MIDR 06.20.45 engine. Using the flexibility of ECD-U2,the US 91 emission targets for NOX and particulates were easily achieved with good fuel economy and the US 94 legislative standard was approached with limited development.
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