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The paper presents the results of investigation of gas-air mixture composition impact on combustion parameters of dual fuel engine operated on CNG (Compressed Natural Gas). The tests were carried out on a single cylinder compression ignition direct injection engine. Combustion parameters calculated on base of recorded indicator diagrams were analysed. The tests have demonstrated capability of dual fuel engine to combustion gas mixtures in wide range of the composition, λCNG=1.8-8.0, with satisfactory efficiency. Reduce of thermal efficiency on partial loads did not exceed 6%. Combustion in dual fuel engine occurs with heat release rate reduced with 40-75% in comparison to conventional engine, what results in reduction of NOx concentration of about 30-35%. Prolongation of ignition delay with 4-6 deg.CA has been observed during the tests, what should be corrected by active change of injection advance angle of pilot dose.

Gasoline Direct Injection engines can have significantly higher particulate mass (PM) and particulate number (PN) emissions relative to equivalent displacement Port Fuel Injected engines. Both the EPA and California Air Resources Board have adopted new stringent standards to be phased in over the next 10 years. The California regulations continue to tighten to a 1 mg/mi PM limit that is phased-in beginning with model year 2025 with full compliance by model year 2028. This study examines the different fuel injection system technology improvements that will be used to attain the standards to as well as their relative costs, market penetration potential, emission reduction and fuel economy impacts. The identification of alternative approaches and the analysis of their impacts was performed in two tasks. The first task was a comprehensive literature review and the findings of the review are presented.

Within a cooperative SHELL-PORSCHE research project the effects of gasoline formulation on emission of regulated and unregulated exhaust gas components and engine performance have been investigated. Both unconventional fuels composed from refinery components and special blends from pure chemicals have been tested on a single cylinder research engine and a 4-cylinder production engine under controlled conditions. CO2-emissions were found to be strongly dependent on fuel carbon content. T90 distillation point has a strong effect on total hydrocarbon emissions. Aromatics content in the fuel is the dominating factor on emission of aromatic hydrocarbons. Aldehyde emissions increased with decreasing aromatic content in the fuel. Oxygenated fuels gave relatively low NOx-emissions. Methane showed very favourable results with respect to all exhaust gas components investigated. With the liquid fuels no effect of fuel composition on engine performance was found.

This paper presents recently derived relationships between gasoline octane quality and vehicle fuel economy measured on a chassis dynamometer. Data are reported from a number of vehicle types, which include both port injection and direct injection technologies. Fuel economy was measured over a fixed test cycle on a matrix of ten fuels. Hence we established an engine/vehicle response to changes in gasoline octane number, in terms of fuel economy. This is comparable with previously reported relationships between gasoline octane quality and engine power output. Finally, fuel economy was measured over a number of industry-standard test cycles, when retail fuels of different octane grade were tested in vehicles. Statistically significant changes in vehicle fuel economy were measured for vehicles that ran on different fuel grades.

During the launch of a car, severe torsional vibration sometimes may occur in its driveline due to somewhat the slipping of the clutch, its intuitive sense for an occupant is the longitudinal vibration of the vehicle, referred to as the launch shudder whose characteristic frequency is from 5 to 25 Hz generally. As the main vibration sources of the driveline and its crucial nonlinear components, the variable stiffness and backlash of the gear meshing are considered, their impacts on the launch shudder are analyzed in this paper. Conformal mapping, finite element method and regression method etc. are the main approaches to calculate the variable meshing stiffness of a gear pair. If this stiffness is get, it can usually be substituted for its approximate analytical expression, just with finite harmonic terms, in Fourier Series form into Ordinary Differential Equations(ODEs) to calculate the vehicle responses with its nonlinearity considered.

Until recently, tool & die making was a very traditional industry, relying on extensive know-how accumulated over decades of practice. Essentially, it remained a two stage-process: engineering/manufacture, followed by tryout/productionization. Improvements focused on engineering and production methods, but tryout remained the exclusive domain of the die maker. At last, advances in computer modeling methods and the adoption of aggressive lean management principles have brought transformational changes to the tryout phase. At the same time, new safety and weight imperatives have increased the penetration of advanced materials, whose formability characteristics are quite different from mild steels. This paper will explore how these advanced materials affect this transformation.

The present paper describes the results of a joint development program focussing on a system approach to meet the EURO IV emission standards for an upper class passenger car equipped with a newly developed high displacement gasoline engine. Based on the well known catalyst systems of recent V6- and V8-engines for the EURO III emission standards with a combination of close coupled catalysts and underfloor catalysts, the specific boundary conditions of an engine with an even larger engine displacement had to be considered. These boundary conditions consist of the space requirements in the engine compartment, the power/torque requirements and the cost requirements for the complete aftertreatment system. Theoretical studies and computer modeling showed essential improvements in catalyst performance by introducing thin wall substrates with low thermal inertia as well as high cell densities with increased geometric surface area.

Doubling or quadrupling the present 12V electrical system provides advantages and disadvantages to many components, and to systems that utilize these components. The effect that this increase has on vehicle electronics starts at the semiconductor component level. Several design implications including technology tradeoffs must be evaluated, and the cost impact on silicon area, processing complexity, and current process limitations considered. This paper focuses on the impact of increasing the system voltage to 24V or 48V with and without centralized load dump transient suppression. The semiconductor devices principally affected are transient suppression devices, power semiconductors, smart power ICs and linear drivers. In addition, the effect of a change in system voltage on MCUs, DSPs, memory devices, and other interface circuits will be discussed.

While hybrid-electric powertrain features such as regenerative braking and electric driving can improve the fuel economy of a vehicle significantly, these features may also have a considerable impact on driving dynamics. That is why extra effort is necessary to ensure safety and comfort that customers usually expect from a conventional vehicle. The purpose of this paper is to initiate a discussion regarding different drivetrain concepts, necessary changes in chassis systems, and the impact on vehicle dynamics. To provide input to this essential discussion, braking and steering systems, as well as suspension design, are analyzed regarding their fit with hybrid systems. It is shown how an integration of hybrid technology and chassis systems benefits vehicle dynamics and why “by-wire” technology is a key enabler for safe and comfortable hybrid-electric vehicles.

This paper deals with specific standards related to air cargo equipment and systems and associated ground equipment produced by ISO/TC20/Subcommittee 9 and why these standards must be recognized in configurating cargo aircraft of the future. Emphasis is placed on standards for cargo unit load devices, i.e., containers (especially the 8 × 8 ft size), pallets, nets and the associated loading equipment as to their role in affecting aircraft design. Various concepts for the wide-body cargo airplane of the future are also explored.

The EPA has issued regulations in the Final Rulemaking for 2017-2025 Light-Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy Standards (420r12901-3). This document provides credits against the fuel economy regulations for various Air Conditioning technologies. One of these credits is associated with increased use of recirculation air mode, when the ambient is over 24°C (75°F.). The authors want to communicate the experiences in their careers that highlighted issues with air quality in the interior of the vehicle cabin. Cabin contamination sources may result in safety and health issues for both younger and older drivers. Alertness concerns may hinder their ability to operate a vehicle safely.

Future light, medium and heavy duty diesel engines will need to satisfy the more stringent emission levels (US 2014, Euro 6, etc.) without compromising their current performance and fuel economy, while still maintaining a competitive cost. In order to achieve this, the Fuel Injection Equipment (FIE) together with the pressure charging, cooling system, exhaust after treatment and other engine sub-systems will each play a key role. The FIE has to offer a range of flexible injection characteristics, e.g. a multiple injection train with or without separation, modulated injection pressures and rates for every injection, higher specific power output from the same injector envelope, and close control of very small fuel injection quantities. The aim of this paper is to present Delphi's developments in fuel injection strategies for light and medium duty diesel engines that will comply with future emission legislation, whilst providing higher power density and uncompromised fuel economy.

One obstacle hindering the use of port fuel injection in natural gas engines is poor idle performance due to incomplete mixing of the cylinder charge prior to ignition. Fuel injection timing has a strong influence on the mixing process. The purpose of this work is to determine the impact of fuel injection timing on in-cylinder fuel distribution. Equivalence ratio maps have been acquired by Planar Laser Induced Fluorescence in an optical engine with a production cylinder head. Experimental results have been used to determine the injection timing which produces the most uniform fuel distribution for the given engine.

Gasoline Direct Injection (GDI) engines have developed rapidly in recent years driven by fuel efficiency and consumption requirements, but face challenges such as injector deposits and particulate emissions compared to Port Fuel Injection (PFI) engines. While the mechanisms of GDI injector deposits formation and that of particulate emissions have been respectively revealed well, the impact of GDI injector deposits and their relation to particulate emissions have not yet been understood very well through systematic approach to investigate vehicle emissions together with injector spray analysis. In this paper, an experimental study was conducted on a GDI vehicle produced by a Chinese Original Equipment Manufacturer (OEM) and an optical spray test bench to determine the impact of injector deposits on spray and particulate emissions.

Control of inlet valve deposit (IVD) formation in port fuel injected (PFI) gasoline spark ignition (SI) engines has been an on-going concern due to the deleterious impact that this material can have on engine performance (power, acceleration times, drivability and fuel consumption). However, decoupling the effects of IVD formation from the multiplicity of other changing engine parameters whilst quantifying the impacts on engine behavior has remained a challenging task to accomplish. A dedicated experimental methodology is presented that has been specifically designed to address this issue. It successfully decouples and quantifies those engine performance impacts that are attributable to IVD formation. Results are presented demonstrating the deleterious impact of IVD formation on fuel consumption in a PFI SI engine.

Cost effective design does not allow for rejection of spacecraft hardware because it cannot be inspected adequately. An actual example of an uninspectable part is presented together with its impact. The rationale of the design-inspection interface is discussed. Some of the influences this interface can have, if not one of complete understanding and cooperation, are: part uninspectable, part costly to inspect, inspection results subject to interpretation, parts cannot be tested nondestructively, part rejection because out of tolerance, part failure, and no accessibility for inspection.

Conventionally, the diesel fuel ignites spontaneously following the injection event. The combustion and injection often overlap with a very short ignition delay. Diesel engines therefore offer superior combustion stability characterized by the low cycle-to-cycle variations. However, the enforcement of the stringent emission regulations necessitates the implementation of innovative diesel combustion concepts such as the low temperature combustion (LTC) to achieve ultra-low engine-out pollutants. In stark contrast to the conventional diesel combustion, the enabling of LTC requires enhanced air fuel mixing and hence a longer ignition delay is desired. Such a decoupling of the combustion events from the fuel injection can potentially cause ignition discrepancy and ultimately lead to combustion cyclic variations.

This paper presents the results of a twenty- vehicle program designed to determine the functional relationship between intake valve deposit level and exhaust emissions. The “identical” 1990 model year vehicles used for this program had accumulated over 80,000 kilometers in taxi fleet service and had developed average intake valve deposit levels which ranged from 6 to 9 on the Coordinating Research Council merit scale. The exhaust emissions from these vehicles were measured in triplicate tests using the 1975 Federal Test Procedure. The intake valve deposits were then mechanically cleaned in-situ, and exhaust emissions were again measured in triplicate. Special procedures were followed to minimize vehicle-to- vehicle variability and to obtain statistically meaning ful results. Results showed intake valve deposits to have a significant adverse effect on exhaust emissions.

In this study, the impact of the intake valve timing on knock propensity is investigated on a dual-fuel engine which leverages a low octane fuel and a high octane fuel to adjust the fuel mixture’s research octane rating (RON) based on operating point. Variations in the intake valve timing have a direct impact on residual gas concentrations due to valve overlap, and also affect the compression pressure and temperature by altering the effective compression ratio (eCR). In this study, it is shown that the fuel RON requirement for a non-knocking condition at a fixed operating point can vary significantly solely due to variations of the intake valve timing. At 2000 rpm and 6 bar IMEP, the fuel RON requirement ranges from 80 to 90 as a function of the intake valve timing, and the valve timing can change the RON requirement from 98 to 104 at 2000 rpm and 14 bar IMEP.

Based on flight test data gathered in general aviation aircraft, a composite motion-noise, passenger comfort model has been developed which enables the assessment of cabin interior noise impact on passenger acceptance. Relationships between special subject responses and passenger responses are given, as well as the effect of comfort on passenger acceptance. The importance of comfort and noise on the overall passenger reaction is discussed.