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Technical Paper

Friction between Piston and Cylinder of an IC Engine: a Review

Engine friction serves as an important domain for study and research in the field of internal combustion engines. Research shows that friction between the piston and cylinder accounts for almost 20% of the losses in an engine and therefore any effort to minimize friction losses will have an immediate impact on engine efficiency and thus vehicle fuel economy. The two most common methods to experimentally measure engine friction are the floating liner method and the instantaneous indicated mean effective pressure (IMEP) method. This paper provides a detailed review of the IMEP method, presents major findings, and discusses sources of error. Although the instantaneous IMEP method is relatively new compared to the floating liner method, it has been used by many scientists and engineers for calculating piston ring assembly friction with consistent results.
Journal Article

Numerical Investigation of Laminar Flame Speed of Gasoline - Ethanol/Air Mixtures with Varying Pressure, Temperature and Dilution

A numerical analysis was performed to study the variation of the laminar burning speed of gasoline-ethanol blend, pressure, temperature and dilution using the one-dimensional premixed flame code CHEMKIN™. A semi-detailed validated chemical kinetic model (142 species and 672 reactions) for a gasoline surrogate fuel was used. The pure components in the surrogate fuel consist of n-heptane, isooctane and toluene. The ethanol mole fraction was varied from 0 to 85 percent, initial pressure from 4 to 8 bar, initial temperature from 300 to 600K, and the EGR dilution from 0 to 32% to represent the in-cylinder conditions of a spark-ignition engine. The laminar flame speed is found to increase with ethanol concentration and temperature but decrease with pressure and dilution.
Journal Article

Effects of Biodiesel Blends on Particulate Matter Oxidation in a Catalyzed Particulate Filter during Active Regeneration

Active regeneration experiments were performed on a production diesel aftertreatment system containing a diesel oxidation catalyst and catalyzed particulate filter (CPF) using blends of soy-based biodiesel. The effects of biodiesel on particulate matter oxidation rates in the filter were explored. These experiments are a continuation of the work performed by Chilumukuru et al., in SAE Technical Paper No. 2009-01-1474, which studied the active regeneration characteristics of the same aftertreatment system using ultra-low sulfur diesel fuel. Experiments were conducted using a 10.8 L 2002 Cummins ISM heavy-duty diesel engine. Particulate matter loading of the filter was performed at the rated engine speed of 2100 rpm and 20% of the full engine load of 1120 Nm. At this engine speed and load the passive oxidation rate is low. The 17 L CPF was loaded to a particulate matter level of 2.2 g/L.
Technical Paper

A Photographic Study of the Combustion of Low Cetane Fuels in a Diesel Engine Aided with Spark Assist

An experimental investigation of the ignition and combustion characteristics of two low cetane fuels in a spark assisted Diesel engine is described. A three cylinder Diesel engine was modified for single cylinder operation and fitted with a spark plug located in the periphery of the spray plume. Optical observations of ignition and combustion were obtained with high speed photography. Optical access was provided by a quartz piston crown and extended head arrangement. The low cetane fuels, a light end, low viscosity fuel and a heavy end, high viscosity fuel which were blended to bracket No. 2 Diesel fuel on the distillation curve, demonstrated extended operation in the modified Diesel engine. Qualitative and quantitative experimental observations of ignition delay, pressure rise, heat release, spray penetration and geometery were compared and evaluated against theoretical predictions.
Technical Paper

The Effect of a Ceramic Trap on Diesel Particulate: Fractions

A study of the Corning ceramic diesel particulate trap was conducted to investigate the trap's overall effect on diesel particulate fractions (soluble organic fraction. SOF; solid fraction, SOL; and sulfate fraction. SO4) under four different engine loads at 1680 rpm. The trap was found to filter the SOL fraction most efficiently with the SOF and SO4 fraction following in respective order. The filter efficiency of all fractions increased with increasing engine load. Graphs illustrating filter efficiency versus engine load indicate the slope of the SOF filter efficiency was smaller in magnitude than the TPM and SOL and SO4, fractions, which had similar slopes. The different slope of the SOF filter efficiency indicates other influences may be involved with the reduction in the SOF through the trap. Particle size distribution measurements in diluted exhaust revealed particle formation downstream of the trap.
Technical Paper

The Influence of an Oxidation Catalytic Converter and Fuel Composition on the Chemical and Biological Characteristics of Diesel Exhaust Emissions

The U.S. Bureau of Mines and Michigan Technological University are collaborating to conduct laboratory evaluations of oxidation catalytic converters (OCCs) and diesel fuels to identify combinations which minimize potentially harmful emissions. The purpose is to provide technical information concerning diesel exhaust emission control to the mining industry, regulators, and vendors of fuel and emission control devices. In this study, an Engelhard PTX 10 DVC (Ultra-10)* OCC was evaluated in the exhaust stream of an indirect injection Caterpillar 3304 PCNA mining engine using a light-duty laboratory transient cycle. This cycle was selected because it causes high emissions of particle-associated organics. Results are also reported for two different fuels with similar sulfur contents (0.03-0.04 wt pct) and a cetane number of 53, but different aromatic contents (11 vs. 20 wt pct).
Technical Paper

A Computational Model Describing the Performance of a Ceramic Diesel Particulate Trap in Steady-State Operation and Over a Transient Cycle

A model for calculating the trap pressure drop, various particulate properties, filtration characteristics and trap temperatures was developed during the steady-state and transient cycles using the theory originated by Opris and Johnson, 1998. This model was validated with the data obtained from the steady-state cycles run with an IBIDEN SiC diesel particulate filter. To evaluate the trap experimental filtration efficiency, raw exhaust samples were taken upstream and downstream of the trap. A trap scaling and equivalent comparison model was developed for comparing different traps at the same volume and same filtration area. Using the model, the trap pressure drop data obtained from different traps were compared equivalently at the same trap volume and same filtration area. The pressure drop performance of the IBIDEN SiC trap compared favorably to the previously tested NoTox SiC and the Cordierite traps.
Technical Paper

The Effect of Fuel Injection Rate and Timing on the Physical, Chemical, and Biological Character of Particulate Emissions from a Direct Injection Diesel

Formation of pollutants from diesel combustion and methods for their control have been reviewed. Of these methods, fuel injection rate and timing were selected for a parametric study relative to total particulate, soluble organic fraction (SOF), sulfates, solids and NO and NO2 emissions from a heavy-duty, turbocharged, after-cooled, direct-injection (DI) diesel. Chemical analyses of the SOF were performed at selected engine conditions to determine the effects of injection rate and timing on each of the eight chemical subfractions comprising the SOF. Biological character of the SOF was determined using the Ames Salmonella/microsome bioassay.
Technical Paper

The Effect of Truck Dieselization on Fuel Usage

The effect of truck dieselization for three levels of diesel penetration into each of the eight classes of trucks is modeled. Diesel and total truck sales, population, mileage and yearly fuel usage data are aggregated by four truck classes representing light, medium, light-heavy and heavy-heavy classes. Four fuel economy scenario's for different technological improvements were studied. Improvement of fuel economy for light and heavy-heavy duty vehicle classes provides significant total fuel savings. Truck dieselization of light and light-heavy duty vehicle classes provides the largest improvement of fuel usage due to the fact that they have large numbers of vehicles and presently have few diesels. Total car and truck fuel usage in the 1980's shows roughly a constant demand with cars decreasing due to improved new fleet fuel economy and trucks increasing due to a larger population with better fuel economy due to dieselization and improved technology.
Technical Paper

Modeling of Early Pressure Rise and Flame Growth in a Spark Ignition Engine

A thermodynamical model of the ignition and flame growth process was developed to understand and minimize cycle-to-cycle variations in pressure due to minor differences in flame kernel growth at the spark plug electrode between cycles. Initial flame kernel size after the spark breakdown process was determined by solving the one-dimensional cylindrical shock flow equation. Overall reaction rates, flame speeds including turbulence and intensity, high temperature equilibrium and other thermodynamic properties were calculated by peripheral sub-models. Relative effects of spark power, heat loss to the spark plug, and the chemical heat release were studied under varying engine conditions. Results show that breakdown energy has a significant effect on the formation and size of the initial kernel and that the effect of flame kernel velocity on subsequent combustion was considerable at specific engine conditions.
Technical Paper

The Effect of Fuel and Engine Design on Diesel Exhaust Particle Size Distributions

The objective of this research was to obtain diesel particle size distributions from a 1988 and a 1991 diesel engine using three different fuels and two exhaust control technologies (a ceramic particle trap and an oxidation catalytic converter). The particle size distributions from both engines were used to develop models to estimate the composition of the individual size particles. Nucleation theory of the H2O and H2SO4 vapor is used to predict when nuclei-mode particles will form in the dilution tunnel. Combining the theory with the experimental data, the conditions necessary in the dilution tunnel for particle formation are predicted. The paper also contains a discussion on the differences between the 1988 and 1991 engine's particle size distributions. The results indicated that nuclei mode particles (0.0075-0.046 μm) are formed in the dilution tunnel and consist of more than 80% H2O-H2SO4 particles when using the 1988 engine and 0.29 wt% sulfur fuel.
Technical Paper

Exhaust Flow Separation in a Two Stroke Engine

The two stroke direct injected gasoline engine is in part characterized by low temperature exhaust flow, particularly at light loads, due to the fresh air scavenging of the combustion chamber during the exhaust process. This study investigated the possibility of separating the exhaust flow into two regimes: 1) high temperature flow of the combustion products, and 2) low temperature flow from the fresh air scavenging process. Separation of the exhaust flow was accomplished by a mechanical device placed in the exhaust stream. In this way, emissions from the exhaust could be handled by two different catalysts and/or processes, each optimized for different temperature ranges and flow compositions. The first portion of this study involved validation of a computer model, using experimental data from a single cylinder engine with a stationary exhaust port and splitter.

Clean Snowmobile Challenge - 3: Refinement of Production Engines and New Control Strategies

This collection is a resource for studying the history of the evolving technologies that have contributed to snowmobiles becoming cleaner and quieter machines. Papers address design for a snowmobile using the EPA test procedure and standard for off-road vehicles, along with more stringent U.S. National Park Best Available Technology (BAT) standards that are likened to those of the California Air Resourced Board (CARB). Innovative technology solutions include: • Standard application for diesel engine designs • Applications to address and test both engine and track noise • Benefits of the Miller cycle and turbocharging The SAE International Clean Snowmobile Challenge (CSC) program is an engineering design competition. The program provides undergraduate and graduate students the opportunity to enhance their engineering design and project management skills by reengineering a snowmobile to reduce emissions and noise.

Emission Control and Fuel Economy for Port and Direct Injected SI Engines

Emission and fuel economy regulations and standards are compelling manufacturers to build ultra-low emission vehicles. As a result, engineers must develop spark-ignition engines with integrated emission control systems that use reformulated low-sulfur fuel. Emission Control and Fuel Economy for Port and Direct Injected SI Engines is a collection of SAE technical papers that covers the fundamentals of gasoline direct injection (DI) engine emissions and fuel economy, design variable effects on HC emissions, and advanced emission control technology and modeling approaches. All papers contained in this book were selected by an accomplished expert as the best in the field; reprinted in their entirety, they present a pathway to integrated emission control systems that meet 2004-2009 EPA standards for light-duty vehicles.

Clean Snowmobile Challenge - 1: The Early Years, 4-Stroke Engines Make Their Debut

This collection is a resource for studying the history of the evolving technologies that have contributed to snowmobiles becoming cleaner and quieter machines. Papers address design for a snowmobile using E10 gasoline (10% ethanol mixed with pump gasoline). Performance technologies that are presented include: • Engine Design: application of the four-stroke engine • Applications to address both engine and track noise • Exhaust After-treatment to reduce emissions The SAE International Clean Snowmobile Challenge (CSC) program is an engineering design competition. The program provides undergraduate and graduate students the opportunity to enhance their engineering design and project management skills by reengineering a snowmobile to reduce emissions and noise. The competition includes internal combustion engine categories that address both gasoline and diesel, as well as the zero emissions category in which range and draw bar performance are measured.
Technical Paper

Relating Integral Length Scale to Turbulent Time Scale and Comparing k-ε and RNG k-ε Turbulence Models in Diesel Combustion Simulation

A modified version of the Laminar and Turbulent Characteristic Time combustion model and the Hiroyasu-Magnussen soot model have been implemented in the flow solver Star-CD. Combustion simulations of three DI diesel engines, utilizing the standard k-ε turbulence model and a modified version of the RNG k-ε turbulence model, have been performed and evaluated with respect to combustion performance and emissions. Adjustments of the turbulent characteristic combustion time coefficient, which were necessary to match the experimental cylinder peak pressures of the different engines, have been justified in terms of non-equilibrium turbulence considerations. The results confirm the existence of a correlation between the integral length scale and the turbulent time scale. This correlation can be used to predict the combustion time scale in different engines.
Technical Paper

Design and Development of the 2001 Michigan Tech FutureTruck, a Power-Split Hybrid Electric Vehicle

In this paper, the conversion of a production SUV to a hybrid electric vehicle with a drive system utilizing a planetary power-split transmission is presented. The uniqueness of this design comes from its ability to couple the advantages of a parallel hybrid with the advantages of a series hybrid. Depending on operating conditions and recent operating history, the drive system transitions to one of several driving modes. The drive system consists of a planetary gear set coupled to an alternator, motor, and internal combustion engine. It performs the power-split operation without the need for belt drives or clutching devices. The effects on driveability, manufacturing, fuel economy, emissions, and performance are presented along with the design, selection, and implementation of all of the vehicle conversion components.
Technical Paper

Performance and Efficiency Assessment of a Production CNG Vehicle Compared to Its Gasoline Counterpart

Two modern light-duty passenger vehicles were selected for chassis dynamometer testing to evaluate differences in performance end efficiency resulting from CNG and gasoline combustion in a vehicle-based context. The vehicles were chosen to be as similar as possible apart from fuel type, sharing similar test weights and identical driveline configurations. Both vehicles were tested over several chassis dynamometer driving cycles, where it was found that the CNG vehicle exhibited 3-9% lower fuel economy than the gasoline-fueled subject. Performance tests were also conducted, where the CNG vehicle's lower tractive effort capability and longer acceleration times were consistent with the lower rated torque and power of its engine as compared to the gasoline model. The vehicles were also tested using quasi-steady-state chassis dynamometer techniques, wherein a series of engine operating points were studied.
Technical Paper

Development of Steel Clad Aluminum Brake

Aluminum based brake rotors have been a priority research topic in the DOE 1999 Aluminum Industry Roadmap for the Automobile Market. After fourteen years, no satisfactory technology has been developed to solve the problem of aluminum's low working temperatures except the steel clad aluminum (SCA) brake technology. This technology research started at Michigan Technological University (MTU) in 2001 and has matured recently for commercial productions. The SCA brake rotor has a solid body and replaces the traditional convective cooling of a vented rotor with conductive cooling to a connected aluminum wheel. Much lower temperatures result with the aluminum wheel acting as a great heat sink/radiator. The steel cladding further increases the capability of the SCA rotor to withstand higher surface temperatures. During the road tests of SCA rotors on three cars, significant gas mileage improvement was found; primarily attributed to the unique capability of the SCA rotor on pad drag reduction.
Technical Paper

Development of a 1-D Catalyzed Diesel Particulate Filter Model for Simulation of the Oxidation of Particulate Matter and Gaseous Species During Passive Oxidation and Active Regeneration

Numerical modeling of aftertreatment systems has been proven to reduce development time as well as to facilitate understanding of the internal physical and chemical processes occurring during different operating conditions. Such a numerical model for a catalyzed diesel particulate filter (CPF) was developed in this research work which has been improved from an existing numerical model briefly described in reference. The focus of this CPF model was to predict the effect of the catalyst on the gaseous species concentrations and to develop particulate matter (PM) filtration and oxidation models for the PM cake layer and substrate wall so as to develop an overall model that accurately predicts the pressure drop and PM oxidized during passive oxidation and active regeneration. Descriptions of the governing equations and corresponding numerical methods used with relevant boundary conditions are presented.