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This paper addresses issues associated with the accurate determination of mass fraction burned (MFB) in gasoline engines. Items covered include an evaluation of the accuracy of alternative MFB models and the effects of errors in the absolute pressure referencing, crank angle phasing and assigned compression ratio. The implications of using crank angle averaged pressure data and varying the crank angle resolution and number of engine cycles are also covered. The well known Rassweiler and Withrow MFB model was found to produce the best results in comparative tests with simulated and experimental pressure data. Absolute pressure referencing offset caused the largest error in the calculated MFB and burn angles, particularly at low engine load. Calculated data at the extreme ends of the MFB curve were shown to be most sensitive to measurement errors and noise.

Engine designers need an objective measurement which can be tested on the engine to indicate acceptable idle quality. An experiment was performed to select objective measures based on cylinder pressure data, and two measures were selected. Standard deviation of indicated mean effective pressure (SDimep) is a measure of the statistical instability of combustion. Lowest normalized value (LNV) is a measure of the tendency toward misfire. These two measures are shown for a set of typical engines. The body of data shows the relation of SDimep and LNV to burn duration and timing.

An automatic failure diagnosis system for engines where we apply motoring test bed and sampled firing test set is proposed in this paper. Focusing on the inspection items where sound signals can be employed, we propose a new approach utilizing wavelet transform, FFT analysis and cepstrum analysis to anomaly characterization. For three important items, namely tappet clicks, misfire and mismatching, the following results have been obtained. (1) For tappet clicks, motoring test is more effective than firing test in recognizing the features of the anomaly. Wavelet transform is more reliable and convenient than FFT analysis to extract the features. (2) For misfire, cepstrum analysis is simple and effective to detect the features. (3) For abnormal combustion sound due to time mismatching, FFT analysis can be applied to extract the features. Further studies are required for finding more effective methods.

Many types of variable speed accessory drive systems have been researched and developed, but none have been adopted in a production car1,2. There has been an increasing demand on the accessory drive system due to the adoption of new accessories in passenger cars. Along with the increasing demand on the system, nothing can be done which would decrease fuel economy. So, the efficiency of the system must be improved. This has caused renewed interest in variable speed accessory drives. A compact V-ribbed (serpentine) belt CVT system for accessory drive (called CVAD: Continuously Variable Accessory Drive System) has been developed3. By applying the CVAD for the accessory belt drive system, fuel savings, increased vehicle performance in acceleration, noise reduction, increased life of accessories and V-ribbed belts, and a reduction in the size of accessories are possible. The performance of a prototype variator, the principal component of the CVAD, has been evaluated.

The objective of this study was to investigate a method to predict brittle failure of silicon nitride ceramics in rolling contact. Fracture mechanics was used to predict crack propagation. Cracks in ceramic rolling elements, like steel, propagate after cyclic stressing in rolling contact. Failure occurs when a crack propagates unstably, or when the stress intensity factor exceeds the fracture toughness. Rolling life was predicted analytically for thrust type rolling contact under dry friction conditions, and compared with experimental results. The experimental lives were distributed near the predicted life curve based on 50% cumulative probability of failure. Consequently, the prediction of rolling life using fracture mechanics is found to be valid to predict reliability against brittle failure of silicon nitride ceramics. From this analysis, the following characteristics were identified as important to maximize resistance to brittle fracture: 1. Short initial crack length 2.

A non-contacting laser displacement meter has been used for dynamic measurements of the radial movement of a v-ribbed belt (type 3PK) around the arc of wrap running on a belt testing rig. Accurate and repeatable results are possible. Using this device, the belt radial movement and the beginning of rib bottom / groove tip contact around the arc of wrap have been determined experimentally for v-ribbed belts. Slip, torque loss, maximum torque capacity and efficiency have been measured during the tests.

Application process, and performance in engine dynamometer and high mileage vehicle fleet durability tests of Plasmaspray coated bore aluminum block engines are discussed. Fuel economy, oil consumption, power and wear data for Ford 4.6L-V8 aluminum block engines utilizing very low cost iron/iron oxide base coatings, and stainless steel/BN solid film lubricant Plasmasprayed coatings are presented. Test results from Ford's 100 hour Piston & Gasket Engine Dynamometer Durability Tests, and Fleet Vehicle Durability Tests show ring/bore wear reductions of more than 40% relative to production cast iron bore systems with Oil Economy averaging more than 13,600 km/l (8000 mi/qt).

In the automotive industry there is a considerable interest to reduce fuel consumption and exhaust fumes. Aluminum materials for car body panels parts such as doors, hood and trunk, have already proved to be an excellent solution for weight saving. However the excess cost induced by weight saving must be kept as low as possible; therefore, aluminum production costs must be controlled. With this aim, Pechiney has developed AA 5182 alloy sheets for inner parts without any surface treatment of the material. Aluminum sheets have been rolled under varying conditions in order to obtain different surface oxides. These products were tested for their joining behavior, especially resistance spot welding and adhesive bonding. The objectives of the study were to determine the effect of rolling parameters and of storage on the oxide film and to compare the weldability lobes and the bonding strength for the different identified oxidation conditions.

The development of a durable adhesive bonding technology for joining of aluminium automotive structures requires a full understanding of the importance of the environment on the chemistry of the adhesively bonded system. This paper describes the accelerated testing procedures used by Alcan to provide information on the significance of environmental factors on adherend surface, the bonding interface and adhesive and so establish the best combination of adhesive and surface pretreatment for good long term durability. The stress/humidity test provides information on adhesive and interface performance, while the neutral salt spray test illustrates durability and corrosion resistance of the pretreatment. Outdoor exposure testing provides the means of comparing the accelerated tests with real life durability.

An investigation describing engine friction reduction benefits attainable via the introduction of Solid Film Lubricants to piston skirts is presented. Ford II-25 thermoset and II-25 waterborne molybdenum disulfide based solid film lubricants were shown through single cylinder motored engine experiments, to produce piston system friction reductions of 12 to 17% at 1500 rpm. Further tests undertaken in fired engine dynamometer studies, on a 1.91 1-4 CVH engine, demonstrated total engine friction reductions of 6% at W.O.T. conditions. The reduced engine friction resulted in lowering BSFC at 850 rpm by 3 to 4%. Tests conducted by Powertrain Operations confirmed durability. II-25 thermoset was selected for production implementation on all new Ford engines starting from model year 1995.

The development process of a water pump impeller used on a sport utility vehicle engine is described. A review of the design process is presented in this paper including the computer-aided flow analysis together with testing procedures. By computer modeling, one can estimate the coolant flow characteristics of a given impeller blade shape for providing increased cooling performance and improved efficiency on the engine. It also provides directions for the improved design. The test data are used specifically to confirm the analysis results.

In the Automotive Industry the need for lower manufacturing costs, to use less strategic materials, and implement easier, faster, and more flexible routes for manufacturing are being looked for continuously. The environmental concerns relating to the use of specific materials (e.g. nickel containing) and galvanic coatings is growing. This has led to the examination of the plasma-powder spray process for the application of coatings for surface modification. In the area of engine cylinder bore coatings a major advance is taking place in the use of a rotating plasma spray device. This paper covers the use of a plasma-powder spray process for the coating of aluminum-silicon cylinder block bores using a rotating plasma gun capable of producing coatings of reliable microstructure and integrity Properties and microstructures of the applied coatings will be presented. Test results will be shown that the necessary bond strength of the coating can be achieved without the use of a bond coat.

This paper will describe the main features of two newly-developed enabling technologies for the future establishment of an integrated system to recover the full value of the aluminum from scrapped aluminum intensive vehicles. These technologies are fluidized bed decoating and alloy sorting using analysis by laser induced optical emission spectroscopy. Aluminum Intensive Vehicles will employ substantial quantities of sheet material, most of which will have fairly heavy paint coatings and possibly adhesives. While it may be possible to remove and segregate some of the closure panels and the major aluminum castings, the main body structure will need to be shredded to facilitate both the separation of the various aluminum and other materials and also the subsequent thermal decoating of paint films and adhesives. The decoating is necessary to ensure complete pyrolysis of the coatings and to avoid the excessive dross losses encountered when as-painted scrap is remelted.

Aluminum foams properties, as energy absorbing materials, were experimentally studied. Having as objective the improvement of the vehicle crashworthiness, two different applications were considered. as a filler material for hollow components of the body frame; in this case the objective is to reinforce weak areas of the frame for a better control of the collapse during the crash; as a material to be employed for the manufacturing of energy absorbing structures for the crashworthiness improvement at low speed impact. Some prototypes were manufactured and tested in order to evaluate the potential benefits for both the applications. Good results obtained in both cases pointed out Al-foam as promising material for increasing the passive safety of the vehicle.

Over the years silver or chrome coated glass has become the dominant material used for automotive visor vanity mirrors. Its durable surface and good reflective qualities made it the material of choice. Specifications surrounding glass are somewhat vague, it is just the material that has been used. With the advent of electropolishing, anodized aluminum is now able to attain excellent finishes on highly pure aluminum. The benefits of anodized aluminum include cost, weight and safety.

The wide application of aluminum alloys as structural materials requires that the surface of the aluminum be pretreated for bonding and corrosion resistance. Traditional surface pretreatment of aluminum alloys involves use of hazardous chemicals such as hexvalent chromium and large amounts of water. In this research, an environmentally benign aluminum alloys surface pretreatment process has been developed. The new process produces a high quality pretreated surface which has strong adhesive bonding and good corrosion resistance. In addition to the benefit for the environment, the new process is simple, low-cost and energy-saving.

Weld bonding of aluminium autobody structures offers automotive vehicle manufacturers the opportunity of achieving significant weight reduction, compared to equivalent steel structures. Further, this is achievable using volume production manufacturing methods. This paper considers all key aspects of the weld bonding process, in particular the equipment requirements and the factors that are important in reliably achieving satisfactory structures. Methods of minimising damage to the adhesive bondline and assessment of spot weld quality are discussed. Using experience gained from extensive weld bonding trials, suitable parameters for robust weld bonding are recommended.

The movement towards extended warranties in the automobile industry has focussed attention on corrosion performance of many components, particularly cast aluminum wheels. Filiform corrosion is of particular concern since it can severely affect the appearance of the wheel. The appearance and the choice of wheel design are the most attractive features to customers. In order to enhance the filiform corrosion resistance of cast aluminum wheels, cleaning, pretreatment, coating and alloy parameters are critical and need to be optimized. In this paper, the effects of alloy composition and condition on filiform corrosion are reviewed. A series of cast discs were prepared with variations in iron, zinc and copper levels around the standard A356.2 alloy composition. Apart from composition, certain specimens were subjected to different heat treatment and ageing conditions. The effects of porosity and different machining procedures were also evaluated.

A study was conducted to determine how the mechanical properties of an A356-T6 Aluminum alloy are affected by solidification time. Solidification time has been found to have a large effect on the microstructure, especially in terms of the size of the SDAS as well as the size and distribution of porosity. Solidification time also has a large effect on the ultimate tensile strength, ductility, and fatigue properties of A356-T6 Al. Comparisons between porosity-containing (“As-Cast) and porosity-free (“As-Cast + HIP”) samples revealed that the presence of porosity had a dramatic effect on fatigue life; tensile properties remained unaffected.

Following their recent experiences in the fields of experimental analysis and numerical simulation of turbocharged engines, the authors present, in this paper, an integrated procedure for studying the behaviour of a light-duty turbocharged D.I. diesel engine, equipped with a variable geometry turbine, an intercooler and an EGR system for NOx control. Experimental activities consist of a complete investigation of the engine operating conditions under different rotational speeds and fuel deliveries. Experimental data provide the basis for numerical investigations. Numerical simulation is carried out through different level of approach, characterised by an increasing level of complexity. A simplified approach of the filling and emptying type is employed for a preliminary determination of matching conditions among the components. Next, a 1-D flow model allows a more correct evaluation of wave propagation phenomena through external ducts.