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The rotary engine provides high power density compared to piston engine, but one of its downside is higher oil consumption. In order to better understand oil transport, a laser induced fluorescence technique is used to visualize oil motion on the side of the rotor during engine operation. Oil transport from both metered oil and internal oil is observed. Starting from inside, oil accumulates in the rotor land during inward motion of the rotor created by its eccentric motion. Oil seals are then scraping the oil outward due to seal-housing clearance asymmetry between inward and outward motion. Cut-off seal does not provide an additional barrier to internal oil consumption. Internal oil then mixes with metered oil brought to the side of the rotor by gas leakage. Oil is finally pushed outward by centrifugal force, passes the side seals, and is thrown off in the combustion chamber.

This work examines the effect of valve timing during cold crank-start and cold fast-idle (1200 rpm, 2 bar NIMEP) on the emissions of hydrocarbons (HC) and particulate mass and number (PM/PN). Four different cam-phaser configurations are studied in detail: 1. Baseline stock valve timing. 2. Late intake opening/closing. 3. Early exhaust opening/closing. 4. Late intake phasing combined with early exhaust phasing. Delaying the intake valve opening improves the mixture formation process and results in more than 25% reduction of the HC and of the PM/PN emissions during cold crank-start. Early exhaust valve phasing results in a deterioration of the HC and PM/PN emissions performance during cold crank-start. Nevertheless, early exhaust valve phasing slightly improves the HC emissions and substantially reduces the particulate emissions at cold fast-idle.

The fuel energy consumption of subsonic air transportation is examined. The focus is on identification and quantification of fundamental engineering design tradeoffs which drive the design of subsonic tube and wing transport aircraft. The sensitivities of energy efficiency to recent and forecast technology developments are also examined.

This paper describes the transient simulation of a single-phase mechanically pumped fluid loop (MPFL) thermal control system, developed in the frame of the European Space Agency ARTES 8 (Advanced Research in Telecommunication Systems - Large Platform Program) program. MPFL is intended to cool a part of the payload on a high power telecommunication satellite. A transient simulation has been implemented using ESATAN/FHTS; hence the results have been correlated with the test results, obtained from full scale MPFL testing, using real on-orbit profiles. The most considerable parts of the activities described herein are simulation of the thermal control law, verification of control parameters during thermo-hydraulic testing and the subsequent correlation.

The scratch resistance of automotive plastic coatings has been studied extensively over the past few years. Most testing methodology to correlate damage of the coating to field conditions has been in the form of small particulate wearing, e.g., alumina oxide abrasive, or indentation resistance of the coating to an external probe, e.g., a nanoindentation device. The subsequent damage imparted to the coating has generally been analyzed by the amount of coating mass lost in the wear event or through a ratio of optical reflectance of the damaged area to the undamaged surface. In this paper, we attempt to delineate surface damage resistance of several automotive clearcoats through an optical interferometry methodology developed to measure volume and depth of damage incurred with small particle alumina oxide erodents in a simulated wear environment.

This paper presents tribological modeling, experimental work, and validation of tribology parameters of a single cylinder turbocharged diesel engine run at various loads, speeds, intake boost pressures, and cylinder liner temperatures. Analysis were made on piston rings and liner materials, rings mechanical and thermal loads, contact pressure between rings and liner, and lubricant conditions. The engine tribology parameters were measured, and used to validate the engine tribology models. These tribology parameters are: oil film thickness, coefficient of friction between rings and liner, friction force, friction power, friction torque, shear rate, shear stress and wear of the sliding surfaces. In order to measure the oil film thickness between rings and liner, a single cylinder AVL turbocharged diesel engine was instrumented to accept the difference in voltage drop method between rings, oil film, and liner.

The life of an automotive engine is often limited by the ability of its components to resist wear. Zinc dialkyldithiophosphate (ZDDP) is an engine oil additive that reduces wear in an engine by forming solid antiwear films at points of moving contact. The effects of this additive are fairly well understood, but there is little theory behind the kinetics of antiwear film formation and removal. This lack of dynamic modeling makes it difficult to predict the effects of wear at the design stage for an engine component or a lubricant formulation. The purpose of this discussion is to develop a framework for modeling the formation and evolution of ZDDP antiwear films based on the relevant chemical pathways and physical mechanisms at work.

A technique to strengthen body frame with a polymeric structural foam has been developed with benefits of reducing vehicle weight and improving drivability and fuel economy. The idea of this new technology was evolved from the concept that body frame strength will increase drastically if the body frames are prevented from folding on collision. The energy of a collision impact would be effectively absorbed if weak portions of body frames are reinforced by a high strength structural foam. The new technology composed of the high strength structural foam and a light-weight frame structure with partial foam filling is reported here.

In recent years, improving fuel efficiency and collision safety are important issue. We have worked on a new construction method to develop body structure which is light weight and strong/stiff. We adopt multi type Tailor-Welded Blanks (TWB) which is formed after welding several steel sheets for ATENZA (MAZDA 6), NEW DEMIO (MAZDA 2), and RX-8. This is a technology to consistently improve of such product properties and to reduce costs. Laser welding is a common TWB welding method, but for further equipment cost reductions and productivity improvements, we have developed a higher welding speed and robust plasma welding and introduced this to mass production. We introduce this activity and results in this report.

Vehicle weight reduction, reduced costs and improved safety performance are the main driving forces behind material selection for automotive applications. These goals are conflicting in nature and solutions will be realized by innovative design, advanced material processing and advanced materials. Advanced high strength steels are engineered materials that provide a remarkable combination of formability, strength, ductility, durability, strain-rate sensitivity and strain hardening characteristics essential to meeting the goals of automotive design. These characteristics act as enablers to cost- and mass-effective solutions. The ULSAB-AVC program demonstrates a solution to these conflicting goals and the advantages that are possible with the utilization of the advance high strength steels and provides a prediction of the material content of future body structures.

Lean-burn technology is now being reviewed again in view of demands for higher efficiency and cleanness in internal combustion engines. The improvement of combustion using in-cylinder gas flow control is the fundamental technology for establishing lean-burn technology, but the great increase in main combustion velocity due to intensifying of turbulence causes a deterioration in performance such as increase in heat loss and N0x. Thus, it is desirable to improve combustion stability while suppressing the increase in main burn velocity as much as possible (1). It is expected that the fluid characteristics of the in-cylinder tumbling motion that the generated vortices during intake stroke breake down in end-half of compression stroke will satisfy the above requisition. This study is concerned with the effects of enhancing of tumble intensity on combustion in 4-valve S. I. engines.

For both notchback-type and fastback-type models, it has been found that critical geometries which increase the aerodynamic drag exist, and the time-averaged wake patterns basically consist of an arch vortex behind the rear window and trailing vortices in the wake. The unsteady characteristics of the wake seem to be directly related to aerodynamic drag. However, the unsteady characteristics of these wake patterns for notchback and fastback cars were not clear. The purpose of present paper is to clarify these phenomena. We try to analyze experimentally the unsteady characteristics by measuring the velocity fluctuations in the wake, the pressure fluctuations on the trunk deck and the drag-force fluctuations acting on the model. At the same time, the analysis of the numerical simulation was made by using the same numerical model as the experimental model. The computed flow visualization behind the rear window showed a fluctuating arch vortex.

In this paper, a prediction method of the aerodynamic sound emitted from the three-dimensional delta wing of the attack angle at 15 degrees is presented. Computed flow Reynolds numbers range from 2.39x1 05 up to 9.56X 105. The method is based on the assumptions: flow Mach number is much less than unity and the strength of sound source equals Curle's dipole. These assumptions are validated by the experimental works performed in a quiet-flow-noise wind tunnel. Owing to the low Mach number condition, the computation region can be devided into two regions: inner flow region and outer wave region. The incompressible flow computation in the inner region is performed based on the full Navier-Stokes equations. The integration of the N-S equations are executed by using finite-difference method. For high Reynolds flow computation, the nonlinear convection terms are discretized by third-order upwind difference scheme.

The thermal fluid field in a headlamp based on the real 3D-CAD model is analyzed by a mesh free method. The conducted method is a new CFD (Computational Fluid Dynamics) solver based on the couples of the points whose density is controlled scattered in the analysis space including the boundaries, which leads to much reduce the hand-working time in the deformation of the 3D-CAD model for the mesh generation. This paper focuses on the steady state airflow field in a headlamp under the conditions of natural ventilation including the effect of the buoyancy and the heat generation of the lamp surface for the demonstration of the conducted method without not only the deformation of the real 3D-CAD model but mesh generation. The differences of the pressure outlet conditions and heat generation of the headlamp on the amount of the ventilation are also experimented.

The quest for higher efficiency and performance of automotive vehicles requires application of materials with high strength, stiffness and lower weight in their construction. Particulate-reinforced aluminum-matrix composites are cost-competitive materials, which can meet these requirements. MMCC, Inc. has been optimizing particulate-reinforced alloy systems and developing the Advanced Pressure Infiltration Casting (APIC™) process for the manufacture of components from these materials. This paper discusses the results of a recent study in which composites reinforced with 55 vol.% alumina were cast using two sizes of alumina particulate and eight different matrix alloys based on Al-4.5 wt.% Cu with varying amounts of silicon and magnesium. Optimum heat treatments for each alloy were determined utilizing microhardness studies. The tensile strength and fracture toughness were evaluated as a function of alloy chemistry, particulate size, and heat treatment.

In order to investigate the corrosion resistance of organic composite-coated steel sheets ( OCS ) in a real automotive environment, many kinds of corrosion tests were performed on test pieces and real automotive doors. Tests with a corrosive solution including iron rust were introduced to simulate the real corrosive environment of automotive doors. The relationship between the components of OCS and the corrosion resistance in the rust-including tests was examined. In addition, electrochemical studies were performed. Results indicate OCS has much better corrosion resistance than plated steel sheets with heavier coating weight in all tests. OCS shows excellent corrosion resistance in rust-free corrosive solution, however, some types of OCS do have corrosion concerns in rust-including tests. It became clear that these OCS types have an organic coating with lower cross-linking.

Mazda established an original design methodology combining a capacitive coupling technology and transmission line theory, to develop a high performance window antenna for AM/FM radios which construction is very simple to construct and requires no use of any antenna boosters or matching circuits. This paper introduces the design methodology and performance characteristics of the new antenna as well as its application to the production '95 model Mazda 929.

ESARAD is an integrated suite of analysis tools for thermal radiative analysis. The suite provides modules for: • Geometry Definition; • Calculation of view factor, radiative exchange factor and solar, albedo and planet flux results; •Visualization of models in orbit with pre- and post-processing of radiative and thermal results; • Reporting of all aspects of the model; and • Generation of Input Files for Thermal Analysis tools. ESARAD is driven by a fully developed GUI, providing the user with a simple, intuitive windows, menus, forms interface to all its features. A modern, block structured language can also be used to run ESARAD. This gives the advanced user great power and flexibility to perform the most complex analyses. ESARAD was designed and developed between 1988 and 1991 to replace the VWHEAT software used by ESA at that time.

Disk brake rotors require reduced unsprung weight and improved cooling ability for improved fade performance. Automotive brake rotors made from aluminum metal matrix composites (MMC) were evaluated by dynamometer and vehicle tests for the required improvement. The friction and wear performance and the thermal response during fade stops were compared with those of commercially produced gray cast iron (GCI) rotors. It was proved that MMC is a very effective material to replace GCI for brake rotor application, as it reduces unsprung weight and decreases maximum operation temperature of the brake system.

The wear patterns of the rings and grooves of a diesel engine were analyzed by using a ring dynamics/gas flow model and a ring-pack oil film thickness model. The analysis focused primarily on the contact pressure distribution on the ring sides and grooves as well as on the contact location on the ring running surfaces. Analysis was performed for both new and worn ring/groove profiles. Calculated results are consistent with the measured wear patterns. The effects of groove tilt and static twist on the development of wear patterns on the ring sides, grooves, and ring running surfaces were studied. Ring flutter was observed from the calculation and its effect on oil transport was discussed. Up-scraping of the top ring was studied by considering ring dynamic twist and piston tilt. This work shows that the models used have potential for providing practical guidance to optimizing the ring pack and ring grooves to control wear and reduce oil consumption.