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Automakers are being subjected to increasingly strict fuel economy requirements which led OEMs to focus more on Light weighting and Energy efficiency areas. Considering the aforesaid challenges, efforts have been taken in Light weighting of mounting bracket for Engine application. This paper deals with conversion of Engine accessory bracket from Aluminum material to Metal Matrix composite (MMC). In Design phase, existing bracket has been studied for its structural requirements and further Bracket is designed to meet MMC process requirement and CAE carried out for topology optimization and Structural integrity. Finally observations and results were compared for Existing design and Proposed design and further optimization proposed.

Diesel particles are formed and also reduced during diffusion-controlled spray combustion in the chamber of a Diesel engine. In earlier investigations it was found that the particles directly sampled near the exhaust valve were irregularly shaped, having a median diameter of 50 to 100 nm. The engine combustion process is cyclic and nonuniform and is imbedded in a highly nonstationary flow. The soot particles formed during the combustion process were emitted during the opening period of the exhaust valve together with the burned gas. This results in strong time-dependent fluctuations of the particle mass density in the exhaust pipe. It is the aim of this study to measure the dynamic particle behaviour during the exhaust gas flow. Laser light scattered by the diesel particles was measured very close to the exhaust valve. The light flux signals obtained under several fixed angles showed a periodic structure and were interpreted in terms of size parameters by applying the Mie theory.

This paper presents an overview of the design process used in the development of an electronic diesel engine control system for industrial, or off-highway applications. The product development process is presented from a systems engineering perspective with emphasis on the key systems engineering methods utilized. One of the major differences between onhighway and off-highway markets is the diversity of applications the off-highway market represents. The industrial controller strives to meet the needs of those diverse applications by employing a large degree of flexibility not only in the way the individual features can be utilized but also in the way the whole system can be applied. Successful incorporation of that flexibility can be attributed to establishing a clear understanding of both the common and unique aspects of the off-highway market and considering those aspects from a total system perspective throughout the development process.

Compacted Graphite Iron (CGI) has been recognized for years as a unique material possessing a fortunate combination of properties intermediate between gray iron and ductile iron. This material, for reasons outlined in this paper, is ideal for cylinder blocks, heads and other cast iron components for diesel engines. It makes possible casting weight savings of up to 1/3 and/or increased power output. This paper will outline reasons why this is now possible, whereas it has seldom been applied in volume production heretofore. Physical and mechanical properties of CGI, which provide the opportunity for weight reduction and increased power, are discussed. Currently, most diesel engine cylinder blocks, heads, liners and many other castings are produced from gray iron, which requires relatively heavy sections to provide the strength, stiffness and durability necessary for commercial application.

Structural attenuation of a running diesel engine measured by a new technique showed a constant value regardless of engine speeds. It was verified by this result that structural attenuation is a physical quantity unique to the structure of each engine and, therefore, a good indicator for evaluation of low noise engine structure. In addition, a hydraulic excitation test rig was devised to measure structural attenuation directly and to make effective use of it for noise reduction. Based on the accurate measurements by the excitation test rig, modal analysis and system simulation were conducted for implementation of countermeasures against noise.

The evolution and explanation of an approach to achieving a stated set of very low emissions limits was described in a previous paper (1)*. The method outlined was to use stoichiometric mixture preparation with EGR dilution in order to employ a 3-way catalyst for low emissions, whilst giving an engine power output competitive with a turbocharged diesel engine. This approach has been followed in an engine development programme, which has resulted in a responsive and driveable engine being produced. The engine has demonstrated the achievability of very low emissions over the US heavy duty diesel transient test (FTP) cycle as follows: The lean-burn approach to low emission heavy duty operation has also been considered, using steady-state engine test results. The NOx-HC trade-off has been identified as a key indicator of engines' potential, and is also considered to give an indication of the accuracy of air-fuel ratio control required to achieve proposed emissions standards.

During the past decade the development of slow speed, turbo-charged and intercooled diesel engines with characteristics to match 9 or 12 speed mechanical transmissions, the use of aerodynamic drag reducing devices, the adoption of radial ply tyres and other mechanically efficient devices has enabled the current semi-trailer tractor to approach the peak of realisable efficiency. The addition of energy storage is perhaps the only method of further reducing the fuel consumption since the utilisation of the potential energy obtained on downhill running for subsequent hill climbing increases the average speed whilst maintaining the same maximum speed. As an energy storage system is most likely to be incorporated with an effective, continuously variable transmission (CVT), the engine can always be operated at maximum efficiency and at lower engine speeds, thus reducing the wear rate.

Considerable development effort has shown that conventional diesel engine lubricating oil specifications do not define the needs for acceptable injector life in methanol-fueled, two-stroke cycle diesel engines. A cooperative program was undertaken to formulate an engine oil-fuel additive system which was aimed at improving performance with methanol fueling. The performance feature of greatest concern was injector tip plugging. A Taguchi matrix using a 100 hour engine test was designed around an engine oil formulation which had performed well in a 500 hour engine test using a simulated urban bus cycle. Parameters investigated included: detergent level and type, dispersant choice, and zinc dithiophosphate level. In addition, the influence of a supplemental fuel additive was assessed. Analysis of the Taguchi Matrix data shows the fuel additive to have the most dramatic beneficial influence on maintaining injector performance.

Three methods of introducing gas into the DDC 8V92TA engine were evaluated: post-pilot in-cylinder injection; early in-cylinder injection just after exhaust valve closure; and port injection through an air inlet port. Post-pilot injection consistently produced the best combustion and HC emissions. Early in-cylinder injection often resulted in severe end gas knock, but gave higher thermal efficiency than diesel in some conditions. HC emissions were considerably higher than for post-pilot injection. Port injection gave smoother combustion than early in-cylinder injection but higher HC emissions. Its full load thermal efficiency tell between, and part load efficiency below, the other methods.

Starting from the real vehicle working conditions and taking that engine works at the optimum economic line as a foundation, this paper gives the power transmissive principle of hybrid vehicle with energy storage flywheel working in process of accelerating, uniformly running and braking, derives the relationship of the ratio and time in continuously - variable transmission(CVT) under working conditions of adjusting engine load, recovering and releasing energy etc., and provides the theoretic foundation for transmission system of flywheel energy storage vehicle to realize optimum economic control.

The proposed wire mesh particulate trap employs a radical design for controlling the regeneration process. A prototype for a 6.2 L diesel engine was designed, built and tested to demonstrate performance characteristics and to correlate with an analytical evaluation. Presented in this paper is the first round of test data achieved thus far. Regeneration is initiated by an electric heating element embedded in the wire mesh, and a single butterfly valve controls the division of flow between the wire mesh and bypass channels. The trap design relies on oxygen in the exhaust gases for regeneration and employs a closed-loop control logic to limit the maximum temperature during regeneration. Test results indicate an ability to achieve high collection efficiencies at low pressure drops and a controlled regeneration process. Work continues to explore the regeneration characteristics under variable engine operating conditions.

Mercedes-Benz have developed their 4, 5 and 6-cylinder Series 300 and 400 diesel engines for the U.S. and Mexican truck markets. These direct injection and air-to-air charge air cooled engines are of low weight and offer the high power-to-size ratio required for modern truck applications. The paper presents an overview of legal regulations in the countries where the engines will be offered and highlights technology needed to meet 1991 U.S. emission limits. It deals with the tuning of the combustion processs, adaptation of injection and turbocharging systems and design of the injection timing system. The new Mercedes-Benz flame heater systems help to further optimize running characteristics of a cold engine in order to meet environmental criteria during starting, warm up and in the running mode. Designing for future, more stringent emission requirements are also discussed. The new engine being introduced is the in-line Mercedes-Benz OM 366 LA.

This paper outlines the design philosophy and evaluation of the new “H” series variable displacement, medium pressure, open-circuit, axial piston hydraulic pumps. The “H” series is based on previously existing, technically successful, rotating group designs, but has significant design improvements affecting the areas of: Unit Weight Envelope Size Ease of Assembly, Disassembly, Repairability and Modification Alternate Fluid Capabilities The “H” series is a family of naturally aspirated pumps nominally rated at 250 or 275 bar (3625 or 4000 psig), depending on system operating parameters. The geometric displacements of the four units in the series are as follows: 57cc (3.5 cu. in./rev.) 74cc (4.5 cu. in./rev.) 98cc (6.0 cu. in./rev.) 131cc (8.0 cu. in./rev.)

Carburetor engines with an inertia governor sometimes exhibit a self-excited oscillation in rotational speed, called hunting. The mechanism of hunting has been extensively studied for many years. It is our general understanding that the dynamic characteristic of the inertia governor is the primary factor to explain the phenomenon. However, the existence of another kind of hunting, called lean hunting, where lag in air-fuel ratio plays a more important role than the dynamic characteristic of the inertia governor, was reported by Tanaka(1,2). His previous papers, showing various experimental measurements of oscillating engine speed, air-fuel ratio and peak cylinder pressure, explain the nature of the phenomenon. To provide the foregoing work with a theoretical ground, we developed a mathematical formulation for the mechanism of lean hunting.

Many diesel engines are equipped with pump-line-nozzle fuel injection systems. These injection systems must be properly tuned in order to achieve the desired fuel delivery without creating secondary injection or cavitation in the injection lines. This paper derives a dynamic model of pump-line-nozzle fuel injection systems that describes how the design variables for the pump, the injection lines and the nozzles are interrelated. Guidelines are presented for tuning these injection systems in order to obtain the desired performance.

A mathematical model of an axial piston pump with a flapper-nozzle valve was developed. The first stage was dynamically stable, and calculated values of first-stage gain and dynamic response agreed well with experimental values. Linearized relations were produced for each component part and were combined to form the total state-variable representation of the model. The open loop system, the combined axial piston pump and flapper-nozzle valve, exhibited dynamic instability. However, when the feedback loop was augmented by the output pressure differential, stability was achieved. From the time responses of the augmented optimal control system, we observed that an increase of input current had little effect on the system response. Doubling the discharge flow rate doubled the overshoot, and an increase in the discharge volume slowed down the system responses. Increasing rotational speed of the pump produced a higher overshoot and a slower response.

A method of calculation is proposed that allows, on the basis of cause-and-sequence approach, to improve the main quantitative characteristics of diesel engines by means of optimization of fuel injection conditions and finding out parameters of fuel injection equipment (TA) for their realization. When using the method, it is assumed that certain technical requirements and limits are to be observed (for instance, the maximum combustion pressure, engine noise, emission standards etc.). The two stages of the method are reflecting the natural sequence of TA design. Components of a developed mathematical model are described in this paper. In particular, special attention is paid to an original phenomenological model of a dispersed fuel spray on the basis of experimental data pertaining to its structure and mixture formation mechanism.

Manufacturers of heavy-duty diesel engines are facing increasingly stringent, emission standards. These standards have motivated new research efforts towards improving the performance of diesel engines. The objective of the present program is to develop a comprehensive analytical model of the diesel combustion process that can be used to explore the influence of design changes. This will enable industry to predict the effect of these changes on engine performance and emissions. A major benefit of the successful implementation of such models is that engine development time and costs would be reduced through their use. The computer model is based on the three-dimensional KIVA-II code, with state-of-the-art submodels for spray atomization, drop breakup / coalescence, multi-component fuel vaporization, spray/wall interaction, ignition and combustion, wall heat transfer, unburned HC and NOx formation, and soot and radiation.

Performance specifications for a corn detasseler position control system were determined. An electrohydraulic position control system was designed and bench tested against the specifications. The bench prototype utilized three different actuators, a 2 inch diameter cylinder, a 6.4 in3 motor, and a 3.0 in3 motor. Each prototype system was tested with a basic carrier bracket load and a complete detassaling assembly load. With a supply of 10 gpm at 2000 psi, a 6.4 in3 motor met the performance requirements. With the same supply, the 2 inch diameter cylinder system was too slow and the 3.0 in3 motor system was unstable.

A quasi-dimensional computer simulation model is presented to simulate the thermodynamic and chemical processes occurring within a spark ignition engine during compression, combustion and expansion based upon the laws of thermodynamics and the theory of equilibrium. A two-zone combustion model, with a spherically expanding flame front originating from the spark location, is applied. The flame speed is calculated by the application of a turbulent entrainment propagation model. A simplified theory for the prediction of in-cylinder charge motion is proposed which calculates the mean turbulence intensity and scale at any time during the closed cycle. It is then used to describe both heat transfer and turbulent flame propagation. The model has been designed specifically for the two-stroke cycle engine and facilitates seven of the most common combustion chamber geometries. The fundamental theory is nevertheless applicable to any four-stroke cycle engine.