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Ethanol fuel has received renewed attention in recent years because of its oxygenate content and its potential to reduce greenhouse gas emissions from spark ignition engines. The economic impact on farm industry has been one of the drivers for its use in engines in the U.S. Although ethanol, in various blends, has been used in automotive engines for almost a decade the fuel has seldom been utilized in off-highway engines where the fuel systems are not well controlled. This investigation was conducted to evaluate exhaust emissions and combustion characteristics of E85 fuel in an off-highway engine used in farm equipment. A single-cylinder, four-stroke, spark ignition engine equipped with a carburetor was used to investigate combustion and exhaust emissions produced by gasoline and blends of gasoline and ethanol fuels. The engine fuel system was modified to handle flow rates required by the engine. A variable size-metering orifice was used to control air-to-fuel ratios.

Structural ceramic components have been successfully operated in a diesel engine. The pistons, liner, and housing for an opposed piston, two-cycle (valveless) engine were fabricated from sintered alpha SiC. The ceramic engine was tested without any lubrication or cooling in the cylinder. Data was collected for both the motoring and firing tests for discussion.

A GT-suite commercial code was used to develop a fully integrated model of a light duty commercial vehicle with a V6 diesel engine, to study the use of a BorgWarner dual mode coolant pump (DMCP) in active thermal management of the vehicle. An Urban Dynamometer Driving Schedule (UDDS) was used to validate the simulation results with the experimental data. The conventional mechanical pump from the validated model was then replaced with the dual mode coolant pump. The control algorithm for the pump was based on controlling the coolant temperature with pump speed. Maximum electrical speed of the pump and the efficiency of the pump were used to determine whether the pump should run in mechanical or electrical mode. The model with the dual mode coolant pump was simulated for the UDDS cycle to demonstrate the effectiveness of control strategy.

Regulations on exhaust emissions from light- and heavy-duty diesel engines have generated interest in high-pressure fuel injection systems. It has been recognized that high-pressure injection systems produce fuel sprays that may be more conductive to reducing exhaust emissions in direct-injection diesel engines. However, for such a system to be effective it must be matched carefully with the engine design and its operating parameters. A common-rail type of fuel injection system was investigated in the present study. The injection system utilizes an intensifier to generate injection pressures as high as 160 MPa. The fuel spray characteristics were evaluated on a test bench in a chamber containing pressurized nitrogen gas. The injection system was then incorporated in a single-cylinder diesel engine. The injection system parameters were adjusted to match engine specifications and its operating parameters.

Gasoline-ethanol blends are being used or have been considered as a fuel for spark ignition engines. The motivation for using the blends varies in indifferent parts of the world and even in regions within a country. The increasing cost of gasoline, combined with regional tax incentives, is one of the reasons for increased interests in gasoline-ethanol blends in recent years in the U.S. Many vehicular engines are not designed to use a specific gasoline-ethanol blend. Rather, the engines have multi-blend capability, ranging from E0 to about E85. It is plausible that engine-out emissions will vary depending on the blend being used which may be further impacted by the level of EGR used with the blends. The present work was carried out to investigate engine out emissions when a vehicular spark-ignition engine was operated on E0 and E85 and different levels of EGR. A 4-cylinder, 2.5 liter, PFI engine was used in the experimental investigation.

A study was conducted to investigate combustion variability and exhaust emissions from high-speed, natural gas fueled engines. Two types of fuel systems were used in the investigation: a mixer and a port fuel injection. The overall engine performances were not much different at stoichiometric fuel-air ratio. But as the equivalence ratio was reduced the engine with the mixer produced higher levels of hydrocarbons and larger coefficient of variations in imep. The same engine exhibited longer flame development angle and rapid burn duration in comparison to the fuel injected engine. The differences in burn durations increased as the equivalence ratio decreased and the mixer system produced larger variations in their values at these operating points. The investigation showed the performance of the engine was better with natural gas injection system than with the mixer, particularly at lean equivalence ratios.

The various methods for calculating AFR from exhaust gas analysis do not always produce identical results. This paper presents exhaust gas analysis data from a four-stroke SI engine burning two different fuels - unleaded gasoline and LPG. Exhaust gas concentrations are measured both upstream and downstream of the three-way catalyst. All four sets of data are analysed using established algorithms due to Spindt, Urban, Uyehara and Fukui. The results of each algorithm are compared with the AFR obtained using direct measurement of air and fuel mass flows.

This paper presents data obtained from a single-cylinder direct injection diesel research engine (121mm bore × 139mm stroke) fitted with a deep torroidal piston cavity but which was fitted with a detachable-port cylinder head and could be operated both with and without swirl. Tests were carried out with a number of different fuel injection pump plunger sizes (which yielded significant changes in injection rate patterns) and the results have been analysed with the aid of a computer program (INJECT) which can be used to determine instantaneous rates of fuel injection, based on data acquired from a firing engine. The results indicate that observed changes in emissions levels can be explained in terms of variations in the instantaneous injection rates. In particular, for a given engine speed, a strong correlation has been shown to exist between NOx emissions and the volume of fuel injected during the ignition delay period, particularly at high engine loads.

Recent stringent government regulations on emission control and fuel economy drive the vehicles and their associated components and systems to the direction of lighter weight. However, the achieved lightweight must not be obtained by sacrificing other important performance requirements such as manufacturability, strength, durability, reliability, safety, noise, vibration and harshness (NVH). Additionally, cost is always a dominating factor in the lightweight design of automotive products. Therefore, a successful lightweight design can only be accomplished by better understanding the performance requirements, the potentials and limitations of the designed products, and by balancing many conflicting design parameters. The combined knowledge-based design optimization procedures and, inevitably, some trial-and-error design iterations are the practical approaches that should be adopted in the lightweight design for the automotive applications.

This paper presents experimental results obtained from bench tests on a 1.4 litre, 4-cylinder, dual-fuel spark ignition engine, fitted with a three-way catalytic converter. Performance, fuel consumption and exhaust emissions measurements were recorded under steady state operating conditions from engine builds: (i) with multi-point gasoline liquid fuel injection, and (ii) with single-point vaporised LPG (propane). An after-market LPG conversion kit, incorporating electronic air-fuel ratio control based on exhaust oxygen concentration, was used in the latter case. Emissions were measured before and after the catalytic converter and catalyst conversion efficiency trends are presented for each fuel. The experimental data is also compared with predictions from a thermodynamic cycle simulation and emissions prediction model which was developed with a view to gaining an improved understanding of the observed experimental trends.

An experimental study was undertaken to investigate emissions of hydrocarbons, oxides of nitrogen, carbon monoxide, and methane hydrocarbons emitted by natural gas fueled engines and the extent of their conversion in catalysts. Two engines were used in the study: a four cylinder, 1.6 liter, spark ignition engine and a modified version of the same engine with only one of the cylinders operating at 0.4 liter capacity. Two-way and three-way catalysts were used to treat exhaust gases leaving the engine. Natural gas was supplied through gas carburetors operated at regulated pressures and supplying air-fuel ratios in the desired range. The results of the investigation showed that oxides of nitrogen could not be reduced in a three-way catalyst to the levels found in gasoline fueled engines when the operating air-fuel ratio was stoichiometric.

The problem of increasing the accuracy of determining the torque and the load angle of the permanent magnet synchronous motor of an electric traction drive to the predicted level (2.5...3)% of the full-scale error is solved by an indirect method. We considered the algorithms for calculating the generalized current and voltage of the electric motor, the total power, the instantaneous values of the power factor, and the sine of the phase angle between the first harmonics of voltages and currents. We determined the requirements for the accuracy of determining these values at the level of 1% of the full-scale error. We considered the algorithms for determining the total instantaneous power losses by the indirect method at the predicted level (15...20)% of the full-scale error with the efficiency of the motor (90...95)%.

The article solves the problem of increasing the energy efficiency of the traction electric drive in the low load conditions. The set objective is achieved by analogy with internal combustion engines by decreasing the consumed energy using the amplitude control of the three-phase voltage of the induction machine. The basis of the amplitude control is laid by the constancy criterion of the overload capacity with respect to the electromagnetic torque, which provides a reliable reserve from a "breakdown" of the induction machine mode in a wide range of speeds and loads. The control system of the traction electric drive contains a reference model of electromechanical energy conversion represented by the generalized equations of the instantaneous balance of the active and reactive power and the mechanical load. The induction machine is controlled by two adaptive variables: the electromagnetic torque and the voltage amplitude.

Charge boosting strategy plays an essential role in improving the power density of diesel engines while meeting stringent emissions regulations. In downsized two-stage turbocharged engines, turbocharger matching is critical to achieve desired boost pressure while maintaining sufficiently fast transient response. A numerical simulation model is developed to evaluate the effect of two-stage turbocharger configurations on the perceived vehicle acceleration. The simulation model developed in GT-SUITE consists of engine, drivetrain, and vehicle dynamics sub-models. A model-based turbocharger control logic is developed in MATLAB using an analytical compressor model and a mean-value engine model. The components of the two-stage turbocharging system evaluated in this study include a variable geometry turbine in the high-pressure stage, a compressor bypass valve in the low-pressure stage and an electrically assisted turbocharger in the low-pressure stage.

This paper presents a new approach to the problem of determining instantaneous rates of fuel injection in direct injection diesel engines. A computer-based analysis tool has been developed which uses experimental data for fuel line pressure (measured at any point downstream of the fuel pump), needle lift and cylinder pressure as inputs to a fluid flow calculation routine. This uses a “method of characteristics” solution to the equations governing unsteady, one-dimensional flow of a compressible liquid in the fuel line and within the injector body. The technique can be used to determine instantaneous injection rates on a cycle-by-cycle basis in a running engine.

This paper describes the results of an experimental programme designed to investigate some effects of intake flow-generated turbulence on rates of combustion and emissions formation in a 91mm bore direct injection diesel engine. Swirl and squish were eliminated as far as possible, in order to isolate the desired effects. This was achieved by re-modelling the inlet port and by replacing the deep bowl piston cavity with a flat-topped version, with the same compression ratio. Tests were carried out with three inlet valves: a standard engine Valve (“A”) and two drilled shrouded valves, one with 15 x 6 mm dia. holes (“B”) and one with 40 x 3.5 mm dia. holes (“C”). The turbulence characteristics associated with each valve were first determined on a steady flow rig, using LDA based surveys of velocity distributions at different downstream distances. The objective was to measure absolute levels of turbulence intensity and to study the subsequent rate of decay.

The diesel engine with direct injection of hydrogen gas has clear advantages over the hydrogen engine with forced ignition of a hydrogen-air mixture. Despite of this, the concept of hydrogen-diesel engine has not investigated until now. In the paper, a detailed study of the working process of hydrogen-diesel engine carried out for the first time. Based on the results of the experimental studies and mathematical modeling, it has established that the behavior of thermo-physical processes in the combustion chamber of hydrogen-diesel engine, in a number of cases, differs fundamentally from the processes that take place in the conventional diesel engines. There have been identified the reasons for their difference and determined the values of the operating cycle parameters of hydrogen diesel engine, which provide the optimal correlation between the indicator values and the environmental performance.

Heat release and instantaneous injection rate data was obtained from a series of experiments on a 121mm bore, single-cylinder, deep-bowl, non-swirling D.I. diesel research engine, using a variety of fuel injection pump builds. Results from tests at constant air-fuel ratio and constant start of combustion angle show that increasing the mean fuel injection kinetic energy (M.I.K.E.) at a given engine speed reduces the heat release time and increases the fuel-air mixing rate. Also, at constant fuel injection kinetic energy, increasing the engine speed increases the fuel-air mixing rate. These experimental trends have been interpreted with the aid of a novel but mathematically very simple analytical approach, based on the hypothesis that all fuel-air mixing in a DI diesel combustion system is promoted by kinetic energy inputs. A “Combined Mixing Efficiency” has been identified which appears to be a characteristic constant of a DI diesel combustion system geometric configuration.

Current plastic intake manifolds are manufactured using the injection molding process. In this paper, thermoforming is explored as an alternative to injection molding for making intake manifold shells, which can then be joined by one of the welding techniques used for thermoplastic materials. The investigation reported here includes press-forming experiments of a simple bowl shaped shell and subsequent welding experiments to join these shells.

An experimental study was undertaken to study exhaust emission from a lean-burn natural gas spark ignition engine. The possibility that such an engine may help to reduce exhaust emissions substantially by taking advantage of natural gas fuel properties, such as its antiknock properties and extended lean flammability limit compared to gasoline, was the main motivation behind the investigation. A four cylinder, automotive type spark ignition engine was used in the investigation. The engine was converted to operate on natural gas by replacing its fuel system with a gaseous carburetion system. A 3-way metal metrix catalytic converter was used in the engine exhaust system to reduce emission levels. The engine operated satisfactorily at an equivalence ratio as lean as 0.6, at all speeds and loads. As a result NOx emissions were significantly reduced. However, hydrocarbon emissions were high, particularly at very lean conditions and light loads.