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Technical Paper

Improving Heavy-Duty Engine Efficiency and Durability: The Rotating Liner Engine

2005-04-11
2005-01-1653
The Rotating Linear Engine (RLE) derives improved fuel efficiency and decreased maintenance costs via a unique lubrication design, which decreases piston assembly friction and the associated wear for heavy-duty natural gas and diesel engines. The piston ring friction exhibited on current engines accounts for 1% of total US energy consumption. The RLE is expected to reduce this friction by 50-70%, an expectation supported by hot motoring and tear-down tests on the UT single cylinder RLE prototype. Current engines have stationary liners where the oil film thins near the ends of the stroke, resulting in metal-to-metal contact. This metal-to-metal contact is the major source of both engine friction and wear, especially at high load. The RLE maintains an oil film between the piston rings and liner throughout the piston stroke due to liner rotation. This assumption has also been confirmed by recent testing of the single cylinder RLE prototype.
Technical Paper

Engine Friction Reduction Through Liner Rotation

2005-04-11
2005-01-1652
Cylinder liner rotation (Rotating Liner Engine, RLE) is a new concept for reducing piston assembly friction in the internal combustion engine. The purpose of the RLE is to reduce or eliminate the occurrence of boundary and mixed lubrication friction in the piston assembly (specifically, the rings and skirt). This paper reports the results of experiments to quantify the potential of the RLE. A 2.3 L GM Quad 4 SI engine was converted to single cylinder operation and modified for cylinder liner rotation. To allow examination of the effects of liner rotational speed, the rotating liner is driven by an electric motor. A torque cell in the motor output shaft is used to measure the torque required to rotate the liner. The hot motoring method was used to compare the friction loss between the baseline engine and the rotating liner engine. Additionally, hot motoring tear-down tests were used to measure the contribution of each engine component to the total friction torque.
Technical Paper

Mixture Preparation During Cranking in a Port-Injected 4-Valve SI Engine

1997-10-01
972982
This paper presents the results of an experimental investigation of the fuel-air mixing process in a port-fuel-injected, 4-valve, spark-ignited engine that was motored to simulate cold cranking and start-up conditions. An infrared fiber-optic instrumented spark plug probe was used to measure the local, crank angle resolved, fuel concentration in the vicinity of the spark gap of a single-cylinder research engine with a production head and fuel injector. The crank-angle resolved fuel concentrations were compared for various injection timings including open-intake-valve (OIV) and closed-intake-valve (CIV) injection, using federal certification gasoline. In addition, the effects of speed, intake manifold pressure, and injected fuel mass were examined.
Technical Paper

Fuel-Spray/Charge-Motion Interaction within the Cylinder of a Direct-Injected, 4-Valve, SI Engine

1998-02-23
980155
The mixture preparation process was investigated in a direct-injected, 4-valve, SI engine under motored conditions. The interaction between the high-pressure fuel jet and the intake air-flow was observed. Laser-sheet droplet imaging was used to visualize the in-cylinder droplet distributions, and a single-component LDV system was used to measure in-cylinder velocities. The fuel spray was visualized with the engine motored at 1500 and 750 rpm, and with the engine stopped. It was observed that the shape of the fuel spray was distorted by the in-cylinder air motion generated by the intake air flow, and that this effect became more pronounced with increasing engine speed. Velocity measurements were made at five locations on the symmetry plane of the cylinder, with the engine motored at 750 rpm. Comparison of these measurements with, and without, injection revealed that the in-cylinder charge motion was significantly altered by the injection event.
Technical Paper

In-Cylinder Fuel Transport During the First Cranking Cycles in a Port Injected 4-Valve Engine

1997-02-24
970043
Fuel transport was visualized within the cylinder of a port injected four-valve SI engine having a transparent cylinder liner. Measurements were made while motoring at 250 rpm to simulate cranking conditions prior to the first firing cycle, and at 750 rpm to examine the effects of engine speed. A production GM Quad-4 cylinder head was used, and the stock single-jet port fuel injector was used to inject indolene. A digital camera was used to capture back-lighted images of cylinder wall wetting for open and closed intake valve injection. In addition, two-dimensional planar imaging of Mie scattering from the indolene fuel droplets was used to characterize the fuel droplet distribution as a function of crank angle for open and closed intake valve injection. LDV was used to measure the droplet and air velocities near the intake valves during fuel induction. It was found that with open-valve injection a large fraction of the fuel impinged on the cylinder wall opposite the intake valves.
Technical Paper

An On-Board Distillation System to Reduce Cold-Start Hydrocarbon Emissions

2003-10-27
2003-01-3239
An On-Board Distillation System (OBDS) was developed to extract, from gasoline, a highly volatile crank fuel that allows the reduction of startup fuel enrichment and significant spark retard during cold starts and warm-up. This OBDS was installed on a 2001 Lincoln Navigator to explore the emissions reductions possible on a large vehicle with a large-displacement engine. The fuel and spark calibration of the PCM were modified to exploit the benefits of the OBDS startup fuel. Three series of tests were performed: (1) measurement of the OBDS fuel composition and distillation curve per ASTM D86, (2) measurement of real-time cold start (20 °C) tailpipe hydrocarbon emissions for the first 20 seconds of engine operation, and (3) FTP drive cycles at 20 °C with engine-out and tailpipe emissions of gas-phase species measured each second. Baseline tests were performed using stock PCM calibrations and certification gasoline.
Technical Paper

The Texas Diesel Fuels Project, Part 2: Comparisons of Fuel Consumption and Emissions for a Fuel/Water Emulsion and Conventional Diesel Fuels

2004-03-08
2004-01-0087
The Texas Department of Transportation began using an emulsified diesel fuel in 2002. They initiated a simultaneous study of the effectiveness of this fuel in comparison to 2D on-road diesel fuel and 2D off-road diesel. The study included comparisons of fuel economy and emissions for the emulsion, Lubrizol PuriNOx®, relative to conventional diesel fuels. Two engines and eight trucks, four single-axle dump trucks, and four tandem-axle dump trucks were tested. The equipment tested included both older mechanically-controlled diesels and newer electronically-controlled diesels. The two engines were tested over two different cycles that were developed specifically for this project. The dump trucks were tested using the “route” technique over one or the other of two chassis dynamometer cycles that were developed for this project In addition to fuel efficiency, emissions of NOx, PM, CO, and HCs were measured. Additionally, second-by-second results were obtained for NOx and HCs.
Technical Paper

The Texas Diesel Fuels Project, Part 3: Cost-Effectiveness Analyses for an Emulsified Diesel Fuel for Highway Construction Equipment Fleets

2004-03-08
2004-01-0086
The Texas Department of Transportation (TxDOT) began using an emulsified diesel fuel as an emissions control measure in July 2002. They initiated a study of the effectiveness of this fuel in comparison to conventional diesel fuel for TxDOT's Houston District operations and included the fleet operated by the Associated General Contractors (AGC) in the Houston area. Cost-effectiveness analyses, including the incremental cost per ton of NOx removed, were performed. NOx removal was the focus of this study because Houston is an ozone nonattainment area, and NOx is believed to be the limiting factor in ozone formation in the Houston area. The cost factors accounted for in the cost-effectiveness analyses included the incremental cost of the fuel (including an available rebate from the State of Texas), the cost of refueling more often, implementation costs, productivity costs, maintenance costs, and various costs associated with the tendency of the emulsion to separate.
Technical Paper

The Texas Diesel Fuels Project, Part 1: Development of TxDOT-Specific Test Cycles with Emphasis on a “Route” Technique for Comparing Fuel/Water Emulsions and Conventional Diesel Fuels

2004-03-08
2004-01-0090
The Texas Department of Transportation (TxDOT) began using an emulsified diesel fuel in July 2002. They initiated a simultaneous study of the effectiveness of this fuel in comparison to 2D on-road diesel fuel, which they use in both their on-road and off-road equipment. The study also incorporated analyses for the fleet operated by the Associated General Contractors (AGC) in the Houston area. Some members of AGC use 2D off-road diesel fuel in their equipment. The study included comparisons of fuel economy and emissions for the emulsified fuel relative to the conventional diesel fuels. Cycles that are known to be representative of the typical operations for TxDOT and AGC equipment were required for use in this study. Four test cycles were developed from data logged on equipment during normal service: 1) the TxDOT Telescoping Boom Excavator Cycle, 2) the AGC Wheeled Loader Cycle, 3) the TxDOT Single-Axle Dump Truck Cycle, and 4) the TxDOT Tandem-Axle Dump Truck Cycle.
Technical Paper

A Full-Cycle Multi-Zone Quasi-Dimensional Direct Injection Diesel Engine Model Based on a Conceptual Model Developed from Imaging Experiments

2017-03-28
2017-01-0537
A quasi-dimensional model for a direct injection diesel engine was developed based on experiments at Sandia National Laboratory. The Sandia researchers obtained images describing diesel spray evolution, spray mixing, premixed combustion, mixing controlled combustion, soot formation, and NOx formation. Dec [1] combined all of the available images to develop a conceptual diesel combustion model to describe diesel combustion from the start of injection up to the quasi-steady form of the jet. The end of injection behavior was left undescribed in this conceptual model because no clear image was available due to the chaotic behavior of diesel combustion. A conceptual end-of-injection diesel combustion behavior model was developed to capture diesel combustion throughout its life span. The compression, expansion, and gas exchange stages are modeled via zero-dimensional single zone calculations.
Technical Paper

Effects of Load on Emissions and NOx Trap/Catalyst Efficiency for a Direct Injection Spark Ignition Engine

1999-05-03
1999-01-1528
A 1998 Toyota Corona passenger car with a direct injection spark ignition (DISI) engine was tested at constant engine speed (2000 rpm) over a range of loads. Engine-out and tailpipe emissions of gas phase species were measured each second. This allowed examination of the engine-out emissions for late and early injection. Regeneration of the lean NOx trap/catalyst was also examined, as was the efficiency of NOx reduction. NOx stored in the trap/catalyst is released at the leading edge of regenerations, such that the tailpipe NOx is higher than the engine-out NOx for a brief period. The efficiency of NOx reduction was <50% for the lowest loads examined. As the load increased, the efficiency of NOx reduction decreased to near 0% due to excessive catalyst temperatures. Loads sufficiently high to require a rich mixture produce high NOx reduction efficiencies, but in this case the NOx reduction occurs via the three-way catalysts on this vehicle.
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

Further Experiments on the Effects of In-Cylinder Wall Wetting on HC Emissions from Direct Injection Gasoline Engines

1999-10-25
1999-01-3661
A recently developed in-cylinder fuel injection probe was used to deposit a small amount of liquid fuel on various surfaces within the combustion chamber of a 4-valve engine that was operating predominately on liquefied petroleum gas (LPG). A fast flame ionization detector (FFID) was used to examine the engine-out emissions of unburned and partially-burned hydrocarbons (HCs). Injector shut-off was used to examine the rate of liquid fuel evaporation. The purpose of these experiments was to provide insights into the HC formation mechanism due to in-cylinder wall wetting. The variables investigated were the effects of engine operating conditions, coolant temperature, in-cylinder wetting location, and the amount of liquid wall wetting. The results of the steady state tests show that in-cylinder wall wetting is an important source of HC emissions both at idle and at a part load, cruise-type condition. The effects of wetting location present the same trend for idle and part load conditions.
Technical Paper

Effect of Fuel Parameters on Emissions from a Direct Injection Spark Ignition Engine During Constant Speed, Variable Load Tests

2000-06-19
2000-01-1909
A 1998 Toyota Corona passenger car with a direct injection spark ignition (DISI) engine was tested at constant engine speed (2000 rpm) over a range of loads. Engine-out and tailpipe emissions of gas phase species were measured each second. This allowed examination of the engine-out emissions for late and early injection. Seven fuels were used for these tests: five blended fuels and two pure hydrocarbon fuels. These seven fuels can be divided into groups for examination of the effects of volatility, MTBE, and structure (an aromatic versus an i-alkane). Correlations between the fuel properties and their effects on emissions are presented. Use of steady state tests rather than driving cycles to examine fuel effects on emissions eliminates the complications resulting from accelerations, decelerations, and changes of injection timing but care had to be taken to account for the periodic regenerations of the lean NOx trap/catalyst.
Technical Paper

Effects of Fuel Parameters on FTP Emissions of a 1998 Toyota with a Direct Injection Spark Ignition Engine

2000-06-19
2000-01-1907
The effects of fuel properties on the emissions of a production vehicle with a gasoline direct injection engine operating over the Federal Test Procedure (FTP) cycle were investigated. The vehicle used was a 1998 Toyota Corona passenger car with a direct injection spark ignition (DISI) engine. Engine-out and tailpipe FTP emissions for six fuels and a California Phase 2 RFG reference fuel are presented. Four of the test fuels were blended from refinery components to meet specified distillation profiles. The remaining test fuels were iso-octane and toluene, an iso-alkane and an aromatic with essentially the same boiling point (at atmospheric pressure) that is near the T50 point for the blended fuels. Statistically significant effects, at the 95% confidence level, of the fuels on tailpipe emissions were found. Correlations were sought between the properties of the five blends and the Emissions Indices for engine-out hydrocarbons and NOx and for tailpipe particulates.
Technical Paper

Effect of Fuel Parameters on Speciated Hydrocarbon Emissions from a Direct Injection Spark Ignition Engine

2000-06-19
2000-01-1908
A 1998 Toyota Corona passenger car with a direct injection spark ignition (DISI) engine was tested over the Federal Test Procedure (FTP) driving cycle. Speciated engine-out hydrocarbon emissions were measured. Seven fuels were used for these tests: five blended fuels and two pure hydrocarbon fuels. One of the blended fuels was CARB Phase 2 reformulated gasoline which was used as the reference fuel. The remaining four blended fuels were made from refinery components to meet specified distillation profiles. The pure hydrocarbon fuels were iso-octane and toluene - an alkane and an aromatic with essentially identical boiling points. The five blended fuels can be grouped to examine the effects of fuel volatility and MTBE. Additionally, correlations were sought between the fuel properties and the Specific Reactivity, the exhaust “toxics”, and the pass-through of unburned fuel species.
Technical Paper

The Effects of In-Cylinder Flow Fields and Injection Timing on Time-Resolved Hydrocarbon Emissions in a 4-Valve, DISI Engine

2000-06-19
2000-01-1905
Direct injection spark-ignition (DISI) engines have been shown to have much higher engine-out hydrocarbon emissions (HC) than port fuel injected (PFI) engines. A major contribution to the increase in HC emissions is from the in-cylinder surface wetting that occurs as the fuel is injected. A previous study using an optical access engine and a fuel concentration probe demonstrated that the in-cylinder flow field and injection timing have a significant effect on the equivalence ratio at the spark plug. This study continues that work, by using a fast spectroscopic HC emission measurement device (Fast-Spec) to study time-resolved HC emissions from a 4-valve, centrally injected, single cylinder DISI engine. Three flow fields are studied: tumble, reverse tumble and stock. The tumble and reverse tumble flow fields are achieved using shrouded valves. Both early and late start of injection (SOI) timings are investigated.
Technical Paper

Effects of Fuel Volatility, Load, and Speed on HC Emissions Due to Piston Wetting

2001-05-07
2001-01-2024
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. In a previous study, we used a variety of pure liquid hydrocarbon fuels to examine the influence of fuel volatility and structure on the HC emissions due to piston wetting. It was 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. All of these prior tests of fuel effects were performed at a single operating condition: the Ford World Wide Mapping Point (WWMP). In the present study, the effects of load and engine speed are examined.
Technical Paper

Refinement of a Dedicated E85 1999 Silverado with Emphasis on Cold Start and Cold Drivability

2001-03-05
2001-01-0679
The University of Texas 2000 Ethanol Vehicle Challenge team remains focused on cold start, cold drivability, fuel economy, and emissions reduction for our 2000 Ethanol Vehicle Challenge entry. We used the stock PCM for all control functions except control of an innovative cold-start system our team designed. The primary modifications for improved emissions control involved ceramic coating of the exhaust manifolds, use of close-coupled ethanol-specific catalysts, use of a moddified version of the California Emissions Calibrated PCM, and our cold-start system that eliminates the need to overfuel the engine at the beginning of the FTP. Additionally, we eliminated EGR at high load to improve power density. Major modifications, such as increasing the compression ratio or pressure boosting, were eliminated from consideration due to cost, complexity, reliability, or emissions penalties.
Technical Paper

The 1983 Formula SAE Championship Competition

1983-09-12
831390
This paper discusses the Formula SAE Student Engineering Design Competition that was held May 26-28, 1983. As was the case of previous student engineering design competitions, the purpose of the Formula SAE Competition is to enhance engineering education by requiring students to apply the technical knowledge gained in their coursework to a practical engineering design problem including choice of appropriate design criteria, design, fabrication, testing, and evaluation. For the Formula SAE Competition, the design problem chosen is to design, construct, and compete a low powered Formula type race car. The purpose of this paper is to describe the 1983 Formula SAE Competition and to present the results of this event. It is expected that this paper will serve as a guide to hosts of similar competitions and will aid future Formula SAE competitors.
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