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The 42-Volt electrical system is being introduced in automobiles to provide the extra power needed for various electromagnetic devices. These paper discuses the opportunity offered by the 42Volt for powder metal parts and the challenges. Major opportunities are in motors. A brief discussion of motors and the performance requirements for the magnetic core material used is included. Brushless motor design can benefit the most from insulated iron powder compacts because of the design simplicity of powder metal parts and three dimensional flux capability which is most beneficial in rotating devices.(P/M stands for powder metallurgy and not permanent magnets)

This paper discusses five different methods for measuring the gas stream temperature from a burner using a hydrocarbon fuel, air, and oxygen. Tests were made with a single shielded BeO probe, a bare wire iridium -- 60% rhodium/iridium couple, a tantalum triple shielded platinum -- 10% rhodium/platinum thermocouple, the sodium line reversed technique, and a watercooled total enthalpy probe. The most serviceable system proved to be the bare wire iridium -- 60% rhodium/iridium couple, particularly for carrying out stream surveys where relative, rather than true temperatures, are of primary concern. More study is needed to establish a system for determining the true stream temperature.

The authors have published SAE paper 2008-01-0088 on the analytical comparison between 4 and 8 counterweight crankshafts for an I4 gasoline engine. This paper showed that for a particular design of a 4 counterweight crankshaft, the differences in bearing force and oil film thickness were very small and the only major difference in terms of bearing shaft tilt angle occurred at mains 2 and 4 (increase of ∼20% compared with 8 counterweight version). The 4 counterweight crankshaft has a significant mass advantage as it was 1.42kg lighter than the 8 counterweight crankshaft. This new paper addresses the testing performed to validate the analysis results in bearing durability by subjecting the engine to a mixture of high speed and general durability cycles. A comparison was made on the bearing conditions after running a total of 100 hours through prescribed durability cycles on a gasoline engine with both 4 and 8 counterweight crankshafts.

Developing lightweight, stiff and crash-resistant vehicle body structures requires a balance between part geometry and material properties. High strength materials suitable for crash resistance impose geometry limitations on depth of draw, radii and wall angles that reduce geometric efficiency. The introduction of 3rd generation Advanced High Strength Steels (AHSS) can potentially change the relationship between strength and geometry and enable simultaneous improvements in both. This paper will demonstrate applicability of 3rd generation AHSS with higher strength and ductility to replace the 780 MPa Dual Phase steel in a sill reinforcement on the current Jeep Cherokee. The focus will be on formability, beginning with virtual simulation and continuing through a demonstration run on the current production stamping tools and press.

Hydrodynamic radial journal bearings under unsteady load, which are common for automotive applications, are exposed to cavitation, e.g. flow, suction, shock and exit cavitation. The fluid mechanic description of the flow in journal bearings takes advantage of the small bearing clearance, which allows the reduction of the Navier-Stokes equations and leads to the Reynolds equation. The Reynolds equation is two-dimensional, the radial pressure gradient and the radial velocity component are neglected. However, the equation includes the surface velocities, oil density and viscosity and describes the relation between hydrodynamic pressure and local clearance. With the introduction of a cavitation index or a mass flow coefficient a powerful method to carry out numerical studies can be created, which allows the calculation of flow properties and the prediction of regions where the lubrication film disintegrates.

To develop injection nozzles and to improve the numerical simulation technology of fuel spray, a measuring technology to analyze the process of disintegration into droplets accurately is required. Performances required by a spray droplets measuring device are: “ability to measure in the combustion condition inside the engine cylinder”, “ability to measure the diameter of spray droplets in high-density fields”, “ability to measure the structure of spray droplets in 3D”, and an improved measuring accuracy of non-spherical droplets. These elements are required in order to analyze the spray droplets structure of gasoline direct injection engines. As a promising method to satisfy these requirements, the laser holography method has been already suggested. However, it has some drawbacks, such as a difficulty in measuring spray droplets in high-density fields and over a long analysis period.

The present paper reports the results of the numerical simulations carried out by means of a modified version of the KIVA-3V code and of the comparison with experimental results obtained by using different optical techniques in a single-cylinder optically accessible diesel engine. The engine is equipped with a commercial four valves cylinder head and a second-generation, Common-Rail injection system. A detailed kinetic model consisting of 283 reactions involving 69 species is applied to simulate the combustion process and the soot and NOx formation. The fuel surrogate model consisting of two constituent components, n-heptane and toluene, approximating the physical and ignition properties of the diesel oil, is considered. The Partially Stirred Reactor (PaSR) assumption is adopted to maintain the computational cost within acceptable limits.

The SI engine combustion model LI-CFM introduced by Boudier et, al. (1992) [8] is extended to deal with actual engines. New models are proposed to simulate ignition with convection at the spark and flame-wall interaction. The scalar properties of the unburnt gases within the combustion zone are computed. This allows for the computation of flame propagation in temperature, fuel and residual gas stratified charges. A model for NO and CO formation is introduced. It is based on a conditional burnt/unburnt averaging of the reaction rates. Pollutants are created at the flamelet level and evolve in the burnt, gases using a mixed equilibrium/kinetic scheme. All these physical models are implemented in a multi-block version of the Kiva 2 code, KMB. This code is used to simulate a 4-valve engine including intake ports. Initial and boundary conditions are obtained from a ID acoustic code.

Multidimensional computations are carried out to aid in the development of a direct injection Diesel engine. Intake, compression, injection and combustion processes are calculated for a turbo-charged direct injection Diesel engine with a single intake valve. The effects of engine speed and engine load, as well as the influence of exhaust gas recirculation are compared to experimental measurements. The influence of piston bowl shape is investigated. Three dimensional calculations are performed using a mesh built from the complete CAD definition of the engine, intake port, cylinder and piston bowl. The injection characteristics are found to be of primary importance in the control of the combustion process. At a given injection set, piston bowl shape can be optimized for fluid dynamic and combustion.

The in-flight ice accretion simulations are typically performed using a quasi-steady formulation through a multi-step approach. As the ice grows, the geometry changes, and an adaptation of the fluid volume mesh used by the airflow and droplet-trajectory solver is required. Re-meshing or mesh deformation are generally employed to do that. The geometries formed are often complex ice shapes increasing the difficulty of the re-meshing process, especially in three-dimensional simulations. Consequently, difficulties are encountered when trying to automate the process. Contrary to the usual body-fitted mesh approach, the use of immersed boundary methods (IBMs) allows solving, or greatly reducing, this problem by removing the mesh update, facilitating the global automation of the simulation. In the following paper, an approach to perform the airflow and droplet trajectory calculations for three-dimensional simulations is presented. This framework utilizes only immersed boundary methods.

Multi-layer steel (MLS) cylinder head gaskets are becoming more widely used to seal an engine. Therefore, it is important to understand the interaction between the engine head, block and head gasket. While experimental methods for determining necessary gasket tightening loads and experimental data relating some gasket design parameters to failure are available, it is very costly and time consuming. A numerical method, such as the finite element (FE) method, has proven to be very useful and efficient in aiding gasket design. A 3D engine FE analysis can predict a number of parameters. Of particular interest are the motion as well as the contact profile of the head, block and gasket. This information, usually difficult or impossible to obtain from a 2D FE analysis, can be used to predict the two most common failure modes of a gasket, fatigue crack and leakage.

This paper presents part of the analytical work performed for the development and optimization of the 3.5L EcoBoost combustion system from Ford Motor Company. The 3.5L EcoBoost combustion system is a direct injected twin turbocharged combustion system employing side-mounted multi-hole injectors. Upfront 3D CFD, employing a Ford proprietary KIVA-based code, was extensively used in the combustion system development and optimization phases. This paper presents the effect of intake port design with various levels of tumble motion on the combustion system characteristics. A high tumble intake port design enforces a well-organized stable motion that results in higher turbulence intensity in the cylinder that in turn leads to faster burn rates, a more stable combustion and less fuel enrichment requirement at full load.

A compound-laser welding method has been developed for the rapid three-dimensional welding of motorcycle aluminum-alloy structural parts. The term “compound-laser welding” means a high-speed welding method in which a number of lasers with different characteristics are arranged on the same axis. This paper reports the results of welding by a compound laser consisting of a YAG laser and a CO2 laser. It was found that compound-laser welding with two or more types of gases mixed as shielding gas gives a better welding performance than single-laser welding due to the advantages of the different lasers used in compound-laser welding.

This project is an experimental investigation and optimization of piston slap noise in small two-stroke gasoline engine. Piston slap is one of the most significant mechanical noise sources in an internal combustion engine. It is a dynamic impact phenomenon between the piston and the cylinder block caused by changes in the lateral forces acting on the piston. The change in cylinder block vibration level caused by the piston impact is considered as a measure of piston slap during this experiment. The intensity of piston slap is measured in terms of vibration level in ‘g’ units, by means of accelerometers mounted on the cylinder block with Top Dead Center (TDC) and Bottom Dead Center (BDC) marker. For the design of low noise engines, all the major parameters, which contribute to piston slap, are listed and the critical four are examined through additional experiments.

Examining the noise reduction of a motorcycle, the requirement of an effective method of reducing a drive chain noise has been a pending issue similarly to noise originating from an engine or exhaust system, etc. Through this study, it became clear that the mechanism of chain noise could be classified into two; low frequency noise originated from cordal action according to the degree of chain engagement and high frequency noise generated by impact when a chain roller hits sprocket bottom. An improvement of urethane resin damper shape, mounted on a drive side sprocket, was effective for noise reduction of the former while our development of a chain drive that combined an additional urethane resin roller with an iron roller worked well for the latter. The new chain system that combined this new idea has been proven to be capable of reducing the chain noise to half compared with a conventional system.

The design of engine intake system affects the intake uniformity of each cylinder of the engine, which in turn has an important impact on the engine performance, the uniform distribution of EGR exhaust gas and the combustion process of each cylinder. In this paper, the constant-pressure supercharged diesel engine intake pipe is used as the research model to study the intake air flow unevenness of the intake pipe of the supercharged diesel engine. The pressure boundary condition at the outlet of each intake manifold is set as the dynamic pressure change condition. The three-dimensional numerical simulation of the transient flow process in the intake manifold of diesel engine is simulated and analyzed by using numerical method, and the change of the Intake air flow field in the intake manifold under different working conditions during the intake overlapping period is discussed.

A 3-D numerical analysis model of transient heat transfer among the multi-component coupling system in combustion chamber of internal combustion engine has been developed successfully in the paper. The model includes almost all solid components in combustion chamber, such as piston assembly, cylinder liner, cylinder head gasket, cylinder head, intake valves and exhaust valves, etc. With two different coupling heat transfer modes, one is the lubricant film heat conduction between two moving components, another is the contact heat conduction between two immovable solid components, and with the direct coupled-field analysis method of FEM, the heat transfer relation among the components is established. The simulation result dedicates the transient heat transfer process among the components such as moving piston assembly and cylinder liner, moving valves and cylinder head. The effect of cylinder head gasket on heat transfer among the components is also studied.

Due to the requirements of the market, engine manufacturers and their suppliers must develop new products in a short lead time, with high quality, high reliability and lowest possible costs. A method to obtain a short lead time for a complicated aluminum cylinder head is the design in 3 D CAD and the use of simultaneous engineering. A practical example shows the design of a 16-valve cylinder head in 3 D CAD (Catia). The cylinder head supplier received a CAD-tape with the main dimensions such as valve locations, shape of the combustion chamber and ports and location of the bolts. A design team completed the cylinder head design in 3 D CAD in consideration of the needs for foundry technology, casting tool design and machining of the part. Special casting tools for the prototyping were manufactured parallel to the cylinder head design.

A surface modification method by electrical discharge has been developed for the valve seats of aluminum cylinder heads. This method employs a conventional electrical discharge machine to generate continuous discharge arcs between an electrode and a cylinder head, whereby the molten electrode material is transferred and clad onto the valve seat area on the cylinder head. Using this new cladding method, a wear-resistant cladding can be formed on each valve seat area in a matter of minutes and, if the same number of electrodes as valve seat areas are set one on one, all the valve seat areas can be clad simultaneously. The advantages of this method include local cladding capability, outstanding adhesion, quick cladding speed, and excellent adaptability to various types of engines. The chemical composition of the cladding was determined by a preliminary test using dynamo engines, and the durability of the cladding was evaluated using the same dynamo engines.

The pistons in a snowmobile engine are subjected to severe temperature conditions not only because snowmobiles are operated in extremely cold temperatures but also because the engine has a high output per unit volume of approximately 150kW/liter. The temperature of the piston top may go from -40°C (when a cold engine is started) to 400°C or higher (when the engine is running at full load). When the piston and cylinder inner wall are cold, the performance of the lubricating oil drops; when they are hot, scuffing may be produced by problems such as tearing of the oil film between the piston and cylinder. When the engine is run at full load for a long time, moreover, the piston is subjected to prolonged high-temperature use, which is conducive to the production of piston boss hole abrasion and ring groove adhesive wear.