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THIS paper describes what the authors consider to be a simplified method of determining the vapor-locking tendencies of gasolines. The study of vapor lock was undertaken after they found the Reid vapor pressure method to be inadequate. The result of their work was the development of the General Motors vapor pressure, a single number which predicts vapor-locking tendency. The authors point out the following advantages of the new method: It allows direct comparisons of vapor-lock test results of different reference fuel systems; establishes distribution curves of volatility requirements of cars for vapor-lock free operation and of vapor-locking tendencies of gasolines; is a common reference value for both petroleum and automotive engineers. Finally, it more realistically evaluates the effects of small weathering losses on vapor-locking tendency than does Rvp.

A rear full overlap car-to-car high speed impact simulation using the DYNA3D Finite Element Software was performed to examine the crush mode for rear structure of a vehicle and to observe the effect of rear bumper system in order to maintain the fuel system integrity. The study was conducted first for two different bumper system configurations, namely: (1) validating the model for struck vehicle with steel rear bumper system, (2) simulating rear end collision with composite rear bumper system attached to the rear rails of struck vehicle. Later a third simulation of the model was conducted with a viable design modification to the composite bumper system for improved crashworthiness. It was identified that a more comprehensive FEA model of the bullet car including front end structure, powertrain components, cooling system and other components which constitute the load paths should be incorporated in the analysis to obtain more meaningful correlation and crashworthiness prediction.

A gasoline direct injection fuel spray was observed using a fired, optical access, square cross-section single cylinder research engine and high-speed video imaging. Spray interaction with the piston is described qualitatively, and the results are compared with Computational Fluid Dynamics (CFD) simulation results using KIVA-3V version 2. CFD simulations predicted that within the operating window for stratified charge operation, between 1% and 4% of the injected fuel would remain on the piston as a liquid film, dependent primarily on piston temperature. The experimental results support the CFD simulations qualitatively, but the amount of fuel film remaining on the piston appears to be under-predicted. High-speed video footage shows a vigorous spray impingement on the piston crown, resulting in vapor production.

The authors are currently developing the MEE (More Electric Engine) electric motor-driven fuel pump system for aircraft engines. The electric fuel system will contribute to the reduction of engine power extraction to drive the fuel pump; thus, an improvement in engine efficiency will be expected. In addition, the engine system reliability will be improved by introducing advanced electric architecture, and the reduction of hydraulic components, fuel tubes and fittings is effective to enhance the maintainability of the engine. Although it is considered that the MEE electric fuel system will realize several benefits, there are technical challenges to introduce such new electric system into aircraft. One of the key technical challenges is to construct a redundant and simplified electric fuel system, because continuous operation of the fuel pump system is crucial for aircraft safety.

A sealed plastic enclosure was proposed in February 1967 by HEW as a technique for measurement of fuel system evaporative emissions from an automobile. Early work with this technique uncovered problems such as car background emissions. Subsequent experimental work, however, has solved these problems and has shown the sealed enclosure capable of correctly measuring total vehicle evaporative emissions. Fuel vapors that actually reach the atmosphere can be measured in a simple, direct way without the necessity for vehicle modification. A complete description of the enclosure is given and its use by GM is described.

FIGURE 1 The 200 HP high performance 4.3L Vortec V6 engine has been developed to satisfy the need for a fuel efficient performance powerplant in the General Motors small truck platforms. Marketing requirements included strong low and mid range torque, relatively high specific power, smoothness and noise comparable to the best competitive six cylinder engines, excellent driveability, and a new technology image. Maintaining the 4.3L engine record of high reliability and customer satisfaction was an absolute requirement. Fuel economy and exhaust emission performance had to meet expected customer and legislated requirements in the mid 1990's.

This paper describes study for fuel pump system configuration which is suitable for the MEE (More Electric Engine) system. The MEE is a new engine system concept which intends engine efficiency improvement, which results in a reduction of engine fuel burn and CO₂ emissions from aircraft. Final configuration of the MEE will contain various engine systems, such as fuel system, oil system and electric generating system, but we focus on high efficiency fuel systems as a first step of the MEE development. The MEE is an advanced engine control technology utilizing recent innovations in electric motors and power electronics and replacing conventional engine accessories, such as AGB-driven pumps and hydraulic actuators with electric motor-driven pumps and EMAs (Electro-Mechanical Actuators), which are powered by generators. Because fuel pump system configuration is a key for the MEE fuel system, we conducted comparison of several pump systems and adopted a fixed displacement gear pump system.

The rear cross-car stiffener subsystem is generally located at the underside of the rear compartment pan of a car body and connects the two rear longitudinal rails or rear rockers. The primary purpose of this subsystem is to maintain structural integrity as well as fuel system integrity in a rear angle impact or dynamic side impact collision. To evaluate the effect of this subsystem on lateral crashworthiness in a high speed angle impact, a finite element model consisting of the cross-car bar, a portion of rear compartment pan and both rear rails was developed and analyzed with the DYNA3D crashworthiness simulation software. Thus, the cross-car stiffener subsystem design including the welding pattern was finalized and the acceptable design was successfully implemented in the vehicle. Subsequently drop silo tests were carried out to further verify the design and to improve the manufacturing process.

Aircraft electrification is one of technological innovations to achieve the goal of CO2 emission reduction in civil aviation. In present research, we focus ourselves on an Electric Fuel Metering System (EFMS). Aircraft systems are commonly expected to make not only simplified configuration and improvement of controllability, but also safety and reliability. The electrification of fuel system also requires the similar approach. Therefore, a simple and reliable redundancy concept is a crucial challenge. In addition, stable and responsive controllability that does not affect engine operation is required, especially in fuel system, it is desired to achieve both accurate metering and short settling time without overshoot or undershoot. However, in such a system, the response is nonlinear due to the fuel flow circuit and the motor drive during current limiting.

The primary objective of Central Port Fuel Injection is to be a low cost multi-point fuel injection system with the additional attributes of compactness, packaging flexibility, and reliability. Performance of this fuel system closely resembles that of a simultaneous multi-point fuel injection system in flow control, dynamic range, cylinder-to-cylinder distribution, idle quality, transient response, and emissions. The system provides significantly improved performance in the areas of hot fuel handling, cold startability, vacuum and voltage sensitivity and system noise. This performance comes at a significant cost savings and greater packaging and targeting flexibility over a conventional multi-point fuel injection system.

This paper describes a concept related to fault-tolerant design for a redundant motor control system. The design comprises components driven by an electric motor, a motor controller, and a power source, referred to as the More Electric Aero Engine (or MEE). The MEE dramatically improves the engine efficiency and reduces fuel burn and CO2 emissions. However, the MEE system must demonstrate that it can ensure engine safety and reliability before it can take the place of conventional systems. The proposed unique redundant system presented in this paper incorporates Active-Active control and multi-winding motors. Engine fuel flow is controlled by the motor speed control of the MEE electric fuel pump, which uses this redundant system. This concept provides a solution for helping to ensure engine safety and reliability, since it enables a complete one-fail operational engine fuel system for the MEE. Another key technology for the MEE system involves a power generating solution.