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Technical Paper

Influence of Ethanol Content in Gasoline on Speciated Emissions from a Direct Injection Stratified Charge SI Engine

2001-03-05
2001-01-1206
The influence of ethanol content in gasoline on speciated emissions from a direct injection stratified charge (DISC) SI engine is assessed. The engine tested is a commercial DISC one that has a wall guided combustion system. The emissions were analyzed using both Fourier transform infrared (FTIR) spectroscopy and conventional emission measurement equipment. Seven fuels were compared in the study. The first range of fuels was of alkylate type, designed to have 0, 5, 10 and 15 % ethanol in gasoline without changing the evaporation curve. European emissions certification fuel was tested, with and without 5 % ethanol, and finally a specially blended high volatility gasoline was also tested. The measurements were conducted at part-load, where the combustion is in stratified mode. The engine used a series engine control unit (ECU) that regulated the fuel injection, ignition and exhaust gas recirculation (EGR).
Technical Paper

A Review of Fuel, Intake and Combustion System Deposit Issues Relevant to 4-Stroke Gasoline Direct Fuel Injection Engines

2001-03-05
2001-01-1202
The recent emergence of production Gasoline Direct Fuel Injection (GDFI) engines into the world markets offers the promise of both improved fuel economy and emissions for 4-stroke Spark Ignition (SI) engines. However with all new technologies there are new challenges that accompany them. The subjects of fuel and intake system and combustion chamber deposits in Port Fuel Injected (PFI) SI engines are well researched and documented. Today only a small amount of specific research exists for GDFI engines [1,2,3,4]. In any case, based on available PFI deposit literature it is possible to make a number of observations about the likely GDFI fuel and intake system deposit issues and their effect on fuel economy, exhaust emissions and performance during a lifetime of service.
Technical Paper

Liquid Film Evaporation Off the Piston of a Direct Injection Gasoline Engine

2001-03-05
2001-01-1204
An optical access engine was used to image the liquid film evaporation off the piston of a simulated direct injected gasoline engine. A directional injector probe was used to inject liquid fuel (gasoline, i-octane and n-pentane) directly onto the piston of an engine primarily fueled on propane. The engine was run at idle conditions (750 RPM and closed throttle) and at the Ford World Wide Mapping Point (1500 RPM and 262 kPa BMEP). Mie scattering images show the liquid exiting the injector probe as a stream and directly impacting the piston top. Schlieren imaging was used to show the fuel vaporizing off the piston top late in the expansion stroke and during the exhaust stroke. Previous emissions tests showed that the presence of liquid fuel on in-cylinder surfaces increases engine-out hydrocarbon emissions.
Technical Paper

The Effects of Fuel Volatility and Structure on HC Emissions from Piston Wetting in DISI Engines

2001-03-05
2001-01-1205
Piston wetting can be isolated from the other sources of HC emissions from DISI engines by operating the engine predominantly on a gaseous fuel and using an injector probe to impact a small amount of liquid fuel on the piston top. This results in a marked increase in HC emissions. All of our prior tests with the injector probe used California Phase 2 reformulated gasoline as the liquid fuel. In the present study, a variety of pure liquid hydrocarbon fuels are used to examine the influence of fuel volatility and structure. Additionally, the exhaust hydrocarbons are speciated to differentiate between the emissions resulting from the gaseous fuel and those resulting from the liquid fuel. It is shown that the HC emissions correspond to the Leidenfrost effect: fuels with very low boiling points yield high HCs and those with a boiling point near or above the piston temperature produce much lower HCs.
Technical Paper

Experimental Investigation of Fuel Consumption and Exhaust Emissions of a 16V Pent-Roof Engine Fueled by Gasoline and CNG

2001-03-05
2001-01-1191
A systematic experimental investigation was undertaken to compare the fuel consumption and exhaust emissions of a production SI engine fueled by either gasoline or compressed natural gas (CNG). The investigation was carried out on a two-liter four-cylinder engine featuring a fast-burn pent-roof chamber, one centrally located spark plug, four valves per cylinder and variable intake-system geometry. The engine was originally designed at Fiat to operate with unleaded gasoline and was then converted at Politecnico di Torino to run on CNG. A Magneti Marelli IAW electronic module for injection-duration and spark-advance setting was used to obtain a carefully controlled multipoint sequential injection for both fuels.
Technical Paper

Dynamic Analysis of a Full System Durability Test in Vehicle Exhaust Systems

2001-04-30
2001-01-1438
A vehicle exhaust system model is implemented into the verified vibration table model. (A dynamic model of the Multi-Axial Simulation Table (MAST) was presented at the SAE 2000 World Congress, Paper No. 2000-01-1187.) The ultimate motivation of this model is to develop and demonstrate advanced dynamic modeling tools in exhaust system design, especially in predicting ‘what if’ situations. The process of the vehicle exhaust system model development is described and the results of a correlation study between the dynamic model analysis, the Full System Durability Test experiments, and the vehicle four-poster tests are presented in this paper. Both sinusoidal and proving ground excitations are used in the experiment. A dynamic model of the rubber isolator is also briefly discussed.
Technical Paper

Nanofluids for Vehicle Thermal Management

2001-05-14
2001-01-1706
Applying nanotechnology to thermal engineering, ANL has addressed the interesting and timely topic of nanofluids. We have developed methods for producing both oxide and metal nanofluids, studied their thermal conductivity, and obtained promising results: (1) Stable suspensions of nanoparticles can be achieved. (2) Nanofluids have significantly higher thermal conductivities than their base liquids. (3) Measured thermal conductivities of nanofluids are much greater than predicted. For these reasons, nanofluids show promise for improving the design and performance of vehicle thermal management systems. However, critical barriers to further development and application of nanofluid technology are agglomeration of nanoparticles and oxidation of metallic nanoparticles. Therefore, methods to prevent particle agglomeration and degradation are required.
Technical Paper

Impact of US02 and Euro4 Emission Legislation on Power Train Cooling Challenges and Solutions for Heavy Duty Trucks

2001-05-14
2001-01-1716
Step by step US and European legislation are defining more stringent emission limits for diesel engines. Depending on these limits for NOx and particulate emissions different emission reduction concepts including or excluding cooled exhaust gas recirculation (EGR) appear over time. Most probable cooled EGR will be the solution for US02 and, in combination with particulate traps, for many Euro4 applications. Competitive aftertreatment solutions like selective catalytic reduction (SCR) may need cooled EGR in addition to meet even tougher emission targets. Therefore cooled EGR can be assumed to be a long term task. The impacts on the power train cooling system arise from the need of high performance EGR systems. This results in increased heat rejection from the EGR cooler and increased pressure and temperature loads on the charge air cooling system.
Technical Paper

Effect of Soot Loading on the Thermal Characteristics of Diesel Engine Oils

2001-05-14
2001-01-1714
When compared with new oil, used diesel engine oils exhibited thermal conductivity that increases as the concentration of soot increases. The magnitude of the effect depends on the oil composition, and on the size and dispersion of the soot particles. Although soot in engine oil is generally deleterious to engine performance from the standpoint of wear and deposits, no negative effects were observed on the thermal performance of the oil itself; indeed, even slight positive effects are expected for oils that maintain soot in stable dispersion. Therefore, the thermal challenge for engine oils in diesel engines that use exhaust gas recirculation will be to prevent soot deposition on engine surfaces.
Technical Paper

An Electronically Tunable Resonator for Noise Control

2001-04-30
2001-01-1615
Many engineering systems create unwanted noise that can be reduced by the careful application of engineering noise controls. When this noise travels down tubes and pipes, a tuned resonator can be used to muffle noise escaping from the tube. The classical examples are automobile exhaust and ventilation system noise. In these cases where a narrow frequency band of noise exists, a traditional engineering control consists of adding a tuned Helmholtz resonator to reduce unwanted tonal noise by reflecting it back to the source (Temkin, 1981). As long as the frequency of the unwanted noise falls within the tuned resonator frequency range, the device is effective. However, if the frequency of the unwanted sound changes to a frequency that does not match the tuned resonator frequency, the device is no longer effective. Conventional resonators have fixed tuning and cannot effectively muffle tonal noise with time-varying frequency.
Technical Paper

New Developments in Molded Polyurethane for Sound Insulation Applications

2001-04-30
2001-01-1555
The continual trend towards weight reduction resulted in the implementation of molded polyurethane carpet underlay at a density of 43 kg/m3 in early 2000. Now, through new formulation developments, coupled with the production introduction of carbon dioxide co-blown technology, additional weight reductions have been achieved. This has resulted in molded densities of 34 kg/m3 to be reached in prototype moldings. In addition to weight reductions, there has also been a renewed focus on improving the acoustical performance of the sound insulation material. As a result, a new family of formulations has been developed which have shown acoustical improvement while not sacrificing weight. This paper will showcase these new developments and highlight the benefits of polyurethane in sound insulation applications.
Technical Paper

Vibrational Power Flow of Rectangular Plates Stiffened by Beams Filled with NOPD

2001-04-30
2001-01-1468
The vibration equation of a stiffened plate is derived and the solutions are obtained by using the Laplace transformation. Input and transmission vibrational power flows of the plate are studied theoretically and experimentally. The studies indicate that Non-Obstructive Particle Damping (NOPD) can restrain the peak values of power flow and its propagation. The effects of different NOPD on the vibrational power flow of structure are discussed. The conclusions provide a theoretical basis for structural optimal design and damping optimal allocation. The method of reducing noise and vibration with NOPD can give some guidelines for engineering.
Technical Paper

Optimization of Vehicle Air Conditioning Systems Using Transient Air Conditioning Performance Analysis

2001-05-14
2001-01-1734
The National Renewable Energy Laboratory (NREL) has developed a transient air conditioning (A/C) system model using SINDA/FLUINT analysis software. It captures all the relevant physics of transient A/C system performance, including two-phase flow effects in the evaporator and condenser, system mass effects, air side heat transfer on the condenser/evaporator, vehicle speed effects, temperature-dependent properties, and integration with a simplified cabin thermal model. It has demonstrated robust and powerful system design optimization capabilities. Single-variable and multiple variable design optimizations have been performed and are presented. Various system performance parameters can be optimized, including system COP, cabin cool-down time, and system heat load capacity. This work presents this new transient A/C system analysis and optimization tool and shows some high-level system design conclusions reached to date.
Technical Paper

Simulating Performance of a Parallel Flow Condenser Using Hydrocarbons as the Working Fluids

2001-05-14
2001-01-1744
Performance of a parallel flow condenser is simulated by using hydrocarbons as the alternative refrigerants. The performance of the condenser is simulated with Propane (R-290), Isobutane (R-600a), and 50/50 mixture (by weight) of Propane and Isobutane. The performance is compared to a system with R-134a as the working fluid. For a given condenser heat rejection capacity, the refrigerant mass flow rates for hydrocarbon refrigerants are significantly lower than R-134a. However, the heat transfer coefficients are comparable in magnitudes to the base case (R-134a) which results in heat transfer rates that are very close to that of the base case. Hence, the simulated rate of heat transfer for hydrocarbon refrigerants is very close (within ±3%) to that of R-134a system. The pressure drop for hydrocarbon refrigerants are significantly lower in comparison to R-134a. The simulated thermal performance has been compared with the experimental test data obtained from the system bench.
Technical Paper

Quantitative In-Cylinder NO-LIF Imaging in a Direct-Injected Gasoline Engine with Exhaust Gas Recirculation

2001-05-07
2001-01-1978
The influence of exhaust gas recirculation (EGR) on the formation of nitric oxide (NO) was studied experimentally in a transparent gasoline direct injection engine by quantitative laser-induced fluorescence imaging. Spectral properties of the excited transition within the NO A2∑+-X2∏(0,2) band are well known from previous studies. The excitation scheme allows quantitative NO concentration measurements without detailed knowledge of the gas phase temperature. Good agreement was found with exhaust gas NOx chemi-luminescence (CLD) measurements. The experiments were carried out in an optically accessible gasoline engine featuring a direct injection cylinder head (BMW) and a Bosch injection system, based on a serial inline six-cylinder engine with an enlarged crankcase. The measurements were performed in the pentroof section of the combustion chamber.
Technical Paper

Particulate Characterization of a DISI Research Engine using a Nephelometer and In-Cylinder Visualization

2001-05-07
2001-01-1976
A nephelometer system was developed to characterize engine particulate emissions from DISI engines. Results were correlated with images showing the location and history of particulates in the cylinder of an optical engine. The nephelometer's operation is based upon the dependence of scattered laser light on particulate size from a flow sampled from the exhaust of an engine. The nephelometer simultaneously measured the scattered light from angles of 20° to 160° from the forward scattering direction in 4° increments. The angular scattering measurements were then compared with calculations using a Mie scattering code to infer information regarding particulate size. Measurements of particulate mass were made based upon a correlation developed between the scattered light intensity and particulate mass samples trapped in a 0.2-micron filter. Measurements were made in a direct injection single-cylinder spark ignition research engine having a transparent quartz cylinder.
Technical Paper

New Standard for Four-stroke Diesel Engine Oils: JASO DH-1

2001-05-07
2001-01-1970
This paper reviews the development of a new standard for four-stroke diesel engine oils, JASO DH-1 (JASO M355: 2000). This standard was introduced to the market on April 1, 2001. It prescribes the minimum performance for engine oils conforming to four-stroke diesel engines manufactured by Japanese OEMs. This standard is composed of four engine tests and seven bench tests. The engine tests include a piston detergency test (JASO M336: 1998), valve train wear test (JASO M354: 1999), soot dispersancy test (ASTM D 5967-99) and high temperature antioxidation test (ASTM D 5533-97a). The piston detergency test and the valve train wear test were developed in Japan. The bench tests measure hot surface deposits, anti-forming, volatility, anti-corrosion, shear-stability, total base number, and seal compatibility.
Technical Paper

New Data on Flame Behaviour in Lean Burn S.I. Engine

2001-05-07
2001-01-1956
The concept of lean-burn combustion in spark ignition engines had been developed for reducing both exhaust emissions and fuel consumption. However the operation of engines in this mode is limited due to the misfire phenomenon. Several studies have been conducted to improve the understanding of the interaction between flow-field, mixture preparation and the progress of combustion. Multidimensional optical diagnostics are an important tool and in the other hand, the work done on combustion modelling in engine becomes more and more relevant but mainly in the case of stoichiometric mixture. The objective of the present work is to provide new information on the flame structure in lean mixtures under different flow field configurations, particularly when the flame is in the laminar-turbulent transition. Classical Mie scattering tomography of flames was performed in a transparent 4-valve Spark Ignition engine.
Technical Paper

Understanding Soot Mediated Oil Thickening: Rotational Rheology Techniques to Determine Viscosity and Soot Structure in Peugeot XUD-11 BTE Drain Oils

2001-05-07
2001-01-1967
The Association des Constructeurs Européen d'Automobiles (ACEA) light duty diesel engine specifications requires a kinematic viscosity measurement technique for Peugeot XUD-11 BTE drain oils. This viscosity measurement is used to define the medium temperature dispersivity of soot in the drain oil.(1) This paper discusses the use of rotational rheology methods to measure the Newtonian character of XUD-11 drain oils. The calculation of the rate index using the Hershel Bulkley model indicates the level of non-Newtonian behavior of the drain oil and directly reflects the level of soot dispersion or agglomeration. This study shows that the more non-Newtonian the drain oil the greater the difference between kinematic and rotational viscosity measurements Oscillation (dynamic) rheological techniques are used to characterize build up of soot structure.
Technical Paper

Lubricants That Optimize Diesel Engine Fuel Economy and Allow Extended Oil Drains

2001-05-07
2001-01-1968
Fleet customers demand reduced operating costs. This necessitates the development of engine oils which can provide maximum fuel economy and extended oil drains, while still maintaining engine durability. This is particularly important in diesel engines produced since October 1998. These engines use retarded timing to meet EPA's emission requirements and, as a consequence in some cases, generate high soot levels in the engine oil. Extended oil drains in 1995 Caterpillar 3406E and 1996 Detroit Diesel Series 60 engines found no statistical difference in fuel economy or wear between a synthetic SAE 5W-40 and an SAE 15W-40 using API Group II base stocks. Both oils had the same API CG-4/SJ quality level. Soot levels at oil drains of 40,000-50,000 miles (64,372 - 80,465 km) ranged from 0.5-1.2%.
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