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Technical Paper

Performance and Exhaust Emission in Spark Ignition Engine Fueled with Methanol-Butane Mixture

1988-03-01
871165
To improve the cold startability of methanol, methanol-butane mixed fuel was experimented. Engine performance and exhaust emissions are obtained with methanol-butane mixed fuel. These characteristics are compared with those of methanol and gasoline. The mixing ratios of methanol and butane are 50:50 (M50), 80:20 (M80), and 90:10 (M90) based on the calorific value. As a result, M90 produces more power than gasoline and more or less than methanol depending on the engine speed and the excess air ratio. Brake horse power of M90 is higher than that of gasoline by 5 - 10 %, and brake specific fuel consumption is smaller than that of gasoline by 17 % to the maximum based on the calorific value. NOx emission concentrations for M90 are lower than those for gasoline and higher than those for methanol because of the effect of butane, CO emission concentrations are somewhat lower than those for methanol and gasoline.
Technical Paper

“Passenger Vehicle Petrol Consumption - Measurement in the Real World”

1988-03-01
871159
A survey of the in-service fuel consumption of passenger vehicles and derivatives in the Australian fleet was carried out in 1984-85. Seven hundred and four owners across Australia took part in the survey. Vehicle owners reported by questionnaire the amount of fuel used during four tank fills of normal operation, the distance travelled, and other details of the operating circumstances. The survey shows a clear downward trend in the fuel consumption of the Australian passenger fleet. The data also provides comparisons of actual fuel consumption obtained on the road, with laboratory derived values for fuel consumption. Vehicles in a sub-set of 40 were fitted with fuel flow meters during the survey and tested to Australian Standard 2077 for fuel consumption. The questionnaire method is shown to be a valid and accurate technique for determining in-service fuel consumption.
Technical Paper

A Procedure for Evaluating Cycle Emissions from Raw Exhaust Gas Analyses

1988-03-01
871194
A procedure has been developed for evaluating equivalent drive cycle emission results from raw exhaust gas emissions data obtained from an engine under test on a computer controlled Vehicle Simulator Engine Dynamometer. The emitted species data is integrated with the air intake flow rate to determine the total mass of emissions, after correcting for the reduction in exhaust gas mass due to precipitation of the moisture of combustion. This procedure eliminates the need for the Constant Volume Sample (CVS) System attached to the vehicle exhaust while undergoing simulated drive testing on a chassis dynamometer to evaluate compliance of the test vehicle with the Australian Design Rules, ADR27 and ADR37. Sources of error with the procedure are examined by comparing the fuel consumption measured using a volumetric technique during the test with that evaluated by a carbon balance procedure as given in the Australian Design Rules.
Technical Paper

Effect of High Squish Combustion Chamber on Simultaneous Reduction of NOx and Particulate from a Direct-Injection Diesel Engine

1999-05-03
1999-01-1502
In this study it is tried to reduce NOx and particulate emissions simultaneously in a direct injection diesel engine based on the concept of two-stage combustion. At initial combustion stage, NOx emission is reduced with fuel rich combustion. At diffusion combustion stage, particulate emission is reduced with high turbulence combustion. The high squish combustion chamber with reduced throat diameter is used to realize two-stage combustion. This combustion chamber is designed to produce strong squish that causes high turbulence. When throat diameter of the high squish combustion chamber is reduced to some extent, simultaneous reduction of NOx and particulate emissions is achieved with less deterioration of fuel consumption at retarded injection timing. Further reduction of NOx emission is realized by reducing the cavity volume of the high squish combustion chamber. Analysis by endoscopic high speed photography and CFD calculation describes the experimental results.
Technical Paper

A Six-Stroke DI Diesel Engine Under Dual Fuel Operation

1999-05-03
1999-01-1500
A six-stroke DI diesel engine proposed by the authors had second compression and combustion processes which were added on a conventional four-stroke diesel engine. This engine had the first and second power strokes before the exhaust stroke. Numerical predictions and experiments previously carried out had shown that this six-stroke diesel engine could reduce NO exhaust emission. Further, the ignition delay of the second combustion process could be shortened by a high temperature effect in the second compression stroke. This advantage of short ignition delay could be utilized for an ignition improvement of a fuel with low cetane number. In the engine system reported here, a conventional diesel fuel was supplied as the fuel of first combustion process, and in the second combustion process, methanol was supplied.
Technical Paper

Effects of a Hybrid Fuel System with Diesel and Premixed DME/Methane Charge on Exhaust Emissions in a Small DI Diesel Engine

1999-05-03
1999-01-1509
Early stage combustion systems, with lean homogeneous charge compression ignition (HCCI), have been studied, with the intent to decrease the pollutant emission characteristics of DI diesel engines. Early stage combustion enables drastic reductions in both nitrogen oxides (NOx) and smoke emission, but the operating load range is restricted, due to combustion phenomena, such as unsteady combustion and knocking. In this study, we explored the possibility of broadening the operating load range in HCCI and reducing pollutant emissions using Dimethyl Ether (DME) fumigated through the intake pipe. However, the improvements in load range were found to be less than 0.1 MPa in brake mean effective pressure (BMEP), even when compression ratios were reduced and Methane with high octane number was mixed. Therefore, a DME premixed charge could be used only at light loads. At heavier loads a hybrid fuel system with a DME premixed charge and diesel fuel injection is necessary.
Technical Paper

Numerical Optimization of Ring-Pack Behavior

1999-05-03
1999-01-1521
The ring-pack behavior in a modern gasoline engine represent complicated phenomena. The process of ring pack design consists of two stages: understanding the physical behavior and design synthesis on the systematic manner. Computer models give an inside on the physical processes associated with the ring-pack behavior. Mathematical optimization techniques provide the tools for design synthesis on the systematic way based on an optimal criteria. The mathematical optimization technique was developed and applied to ring pack design synthesis. When applied to the existing engine ring-pack designs, the optimized results indicated the potential for significant reduction in blow-by through the ring-pack by optimizing ring pack geometry. The optimization results were compared with the original ring pack designs for two gasoline engines for a wide range of operating conditions.
Technical Paper

Emissions and Fuel Economy of a 1998 Toyota with a Direct Injection Spark Ignition Engine

1999-05-03
1999-01-1527
A 1998 Toyota Corona passenger car with a direct injection spark ignition (DISI) engine was tested via a variety of driving cycles using California Phase 2 reformulated gasoline. A comparable PFI vehicle was also evaluated. The standard driving cycles examined were the Federal Test Procedure (FTP), Highway Fuel Economy Test, US06, simulated SC03, Japanese 10-15, New York City Cycle, and European ECE+EDU. Engine-out and tailpipe emissions of gas phase species were measured each second. Hydrocarbon speciations were performed for each phase of the FTP for both the engine-out and tailpipe emissions. Tailpipe particulate mass emissions were also measured. The results are analyzed to identify the emissions challenges facing the DISI engine and the factors that contribute to the particulates, NOx, and hydrocarbon emissions problems of the DISI engine.
Technical Paper

The CRC Port Fuel Injector Bench Test Method, Interlaboratory Study, and Vehicle Test Correlation

1999-05-03
1999-01-1548
Port-fuel-injection (PFI) problems were first reported late in 1984. Deposits that formed on the tip of the pintle-type injectors of certain engines restricted fuel flow and caused driveability and emission problems. Responding to this problem, industry test programs were initiated to reproduce the deposits under controlled conditions. In 1986, a vehicle test procedure was identified and the automotive industry recommended a pass/fail performance level. Building upon available information, the Coordinating Research Council's (CRC) Port Fuel Injector Deposit Group developed a standard vehicle test procedure to evaluate various unleaded gasolines for port-fuel-injection fouling. The vehicle test procedure was adopted as an ASTM test method. The United States Environmental Protection Agency (EPA) and the State of California accepted the procedure as the standard for measuring a gasoline's propensity to form deposits in a pintle-type injector.
Technical Paper

Fuel Quality Control by Mid Infrared Spectroscopy

1999-05-03
1999-01-1546
Gasolines and diesel fuels of wide source were analyzed with the aim to predict the quality through the mid infrared spectroscopy and the algorithms PCA-PCR and PLS. The results revealed that octane number, cetane number, MTBE, benzene, aromatics and specific gravity could be predicted with good reliability. The other relevant fuel physical-chemical characteristics were beyond the precision of the standard test methods.
Technical Paper

Exhaust Particulate Matter Emissions from In-Use Passenger Vehicles Recruited in Three Locations: CRC Project E-24

1999-05-03
1999-01-1545
FTP-UDDS (urban dynamometer driving schedule) exhaust particulate matter (PM) emission rates were determined for 361 light-duty gasoline (LDGV) and 49 diesel passenger vehicles ranging in model year (MY) from 1965 to 1997. LDGVs were recruited into four MY categories. In addition, special effort was made to recruit LDGVs with visible smoke emissions, since these vehicles may be significant contributors to the mobile source PM emission inventory. Both light and heavy-duty diesels where included in the passenger diesel test fleet, which was insufficient in size to separate into the same MY categories as the LDGVs. Vehicles were tested as-received in three areas: Denver, Colorado; San Antonio, Texas; and the South Coast Air Quality Management District, California. The average PM emission rates were 3.3, 79.9, 384 and 558 mg/mi for 1991-97 MY LDGVs, pre-1981 LDGVs, smoking LDGVs and the diesel vehicles, respectively.
Technical Paper

Heavy Duty Testing Cycles Development: A New Methodology

2000-06-19
2000-01-1860
Testing cycles for heavy-duty vehicles are an important topic for authorities, manufacturers, fleet owners, etc. in order to assess exhaust gas emissions and fuel consumption. A new methodology was developed to derive representative testing cycles from velocity versus time driving information. During the development, the work was focussed on city-buses, but the methodology can be applied to heavy-duty vehicles in general. The testing cycles are ‘distance-based’, meaning they impose goal speeds at each location. This implies that during acceleration phases, the accelerator-pedal - and gear lever in case of manual transmission - can be operated in a realistic way. The techniques for deriving this kind of testing cycle are proposed. Results of on-board emission and fuel consumption measurements employing these testing cycles are presented for two 19 tons, 160kW city buses, equipped with respectively a diesel and a CNG (stoechiometric) engine, and a 10 tons 112 kW diesel delivery truck.
Technical Paper

The Systematic Evaluation of Twelve LP Gas Fuels for Emissions and Fuel Consumption

2000-06-19
2000-01-1867
The effects on bi-fuel car exhaust emissions, fuel consumption and acceleration performance of a range of LPG fuels has been determined. The LPGs tested included those representing natural gas condensate and oil refineries' products to include a spectrum of C3:C4 and paraffiinic:olefinic mixtures. The overall conclusions are that exhaust emissions from the gaseous fuels for the three-way catalyst equipped cars tested were lower than for gasoline. For all the LPGs, CO2 equivalent emissions are reduced by 7% to 10% or more compared with gasoline. The cars' acceleration performance indicates that there was no sacrifice in acceleration times to various speeds, with any gaseous fuel in these OEM developed cars.
Technical Paper

Improvement of Performance and Exhaust Emissions in a Converted Dual-Fuel Natural Gas Engine

2000-06-19
2000-01-1866
To improve performance and exhaust emissions of a converted dual-fuel natural-gas engine, the effects of basic parameters were experimentally investigated. The results show that diesel fuel operation is favorable at very low loads and that a small amount of pilot fuel with a moderate injection rate is effective for suppressing knock at high loads. As for the charge air throttling, there is an optimal combination of charge amount and equivalence ratio to obtain high thermal efficiency and reduced emissions. An optimal strategy for fueling is demonstrated based on the results. Adequate control of pilot fuel amount, injection timing and throttle opening area gives diesel-equivalent thermal efficiency with very low smoke emission over a wide range of loads.
Technical Paper

Basic Understanding of Activated Radical Combustion and Its Two-Stroke Engine Application and Benefits

2000-06-19
2000-01-1836
For a better understanding of the auto-ignition phenomenon in internal combustion engines, consideration is given from the in-cylinder gas temperature aspect. Experimental results demonstrate that the in-cylinder gas temperature at the end of compression, namely, the “auto-ignition temperature” is deeply involved in the onset of auto-ignition. The relation between the gas exchange state and the auto-ignition temperature explains the mechanism of timing controlled auto-ignition, namely, Activated Radical (AR) Combustion. The auto-ignition temperature is maintained constant during the AR combustion state, thanks to the exhaust valve controlling the hot residual gas amount. Finally, the utilization of auto-ignition in gasoline engines is discussed from the methodology aspect.
Technical Paper

Performance and Emission Analysis of a Non-Conventional Gasoline Engine

2000-06-19
2000-01-1840
A new engine design concept, characterized by a single cylinder-double piston and a cycloid crank rotor instead of the conventional crankshaft has been developed recently by Gul & Co Development AB, Sweden. The rotor (crank disc) is equipped with an oval groove in the shape of a sinusoidal cycloid according to the expression varies from 0 to 1. Inside the oval groove a ball rolls/slides in order to transfer force from the piston to the rotor. Such a rotor contains groove surfaces for the valve movement control as well. Each turn of the rotor corresponds to four strokes for both the pistons. Thus, a full 4-stroke engine cycle is developed for a single non-conventional crankshaft revolution. Having the extra freedom to select an optimal piston movement, the new design is believed to have the potential to provide low emissions, low noise levels and lower fuel consumption. Therefore, it has been subjected to an engine thermodynamics simulation, to provide an insight to engine performance.
Technical Paper

Performance Development of the First European Heavy Duty Diesel Engine Equipped with Full Electronic High Injection Pressure Common Rail System

2000-06-19
2000-01-1821
Over the last few years, Renault VI has gained an important knowledge in low emissions combustion optimization using the high injection pressure Common Rail system. A completely new six cylinder in-line DCI 11 engine has been designed with this full electronic injection system for EURO3 truck applications. The engine performance has been optimized to reach low fuel consumption and low emissions, while keeping customer utilization in mind. After a short view on the general features of the new engine, the highly flexible injection system is presented as well as its potential to control fuel injection timing, fuel quantity and pressure with multiple injections, independently of engine speed and load. The development process is described, covering the swirl design with two inlet ports per cylinder, the injector and combustion bowl geometry match and the injection data optimization.
Technical Paper

Numerical Investigation of Vehicles Aerodynamics through Driving Tunnels

2000-04-02
2000-01-1579
Due to the rapid development in many parts of Egypt, construction of a wide road network is maintaining a rapid pace. But, those roads are affected by the overcrowded big cities. Thus, there is a growing need for driving tunnels to reduce the traffic problems and facilitate transportation. This issue is highly related to economic (fuel consumption) and environmental (pollution and noise) matters. Up to our knowledge, this paper represents the first numerical study to concern driving tunnels in the Middle East. Actual domestic tunnels and vehicles are computationally simulated. Investigations concentrate on flow behavior, especially overall drag coefficient and wake structure behind vehicles. Results show that many parameters, such as tunnel height, and vehicle height and speed, affect the aerodynamic characteristics through driving tunnels.
Technical Paper

Evaluation of an Unconventional Diesel Engine as a General Aviation Powerplant

2000-05-09
2000-01-1685
A novel two stroke cycle diesel engine is evaluated as a general aviation aircraft powerplant. Two certificated spark-ignited gasoline reciprocating engines are also evaluated in the same aircraft. The evaluation of aircraft propulsion performance considered only the effects of altered powerplant parameters on the range of an aircraft having a fixed gross weight and payload cruising at a given lift/drag ratio. Thermodynamic analysis finds the diesel engine can have a sea level power rating exceeding the 10,000 foot cruise power requirement by 55% with nearly equal specific fuel consumption, a low engine speed and a modest cylinder pressure. It uses a single-stage, radial turbocharger without intercooling or auxiliary mechanical scavenging. The diesel engine can significantly increase the range of a particular airplane now powered by a certificated turboprop engine. The candidate gasoline engines could not equal the turboprop-powered aircraft performance.
Technical Paper

Non-Thermal Plasma System Development for CIDI Exhaust Aftertreatment

2000-04-02
2000-01-1601
There is a need for an efficient, durable technology to reduce NOx emissions from oxidative exhaust streams such as those produced by compression-ignition, direct-injection (CIDI) diesel or lean-burn gasoline engines. A partnership formed between the DOE Office of Advanced Automotive Technology, Pacific Northwest National Laboratory, Oak Ridge National Laboratory and the USCAR Low Emission Technologies Research and Development Partnership is evaluating the effectiveness of a non-thermal plasma in conjunction with catalytic materials to mediate NOx and particulate emissions from diesel fueled light duty (CIDI) engines. Preliminary studies showed that plasma-catalyst systems could reduce up to 70% of NOx emissions at an equivalent cost of 3.5% of the input fuel in simulated diesel exhaust. These studies also showed that the type and concentration of hydrocarbon play a key role in both the plasma gas phase chemistry and the catalyst surface chemistry.
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