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Technical Paper

Potential Improvements in Turbofan’s Performance by Electric Power Transfer

2018-10-30
2018-01-1962
Bleeding in engines is essential to mitigate the unmatched air massflow between low and High Pressure (HP) compressors at low speed settings, thus avoiding unstable operation due to surge and phenomena. However, by emerging the More Electric Aircraft (MEA) the engine is equipped with electrical machines on both high and Low Pressure (LP) spools which enables transfer of power electrically from one spool to another and hence provides the opportunity to operate engine core components closer to their optimum design point at off-design conditions. At lower power setting of the engine, HPC speed can be increased by taking power from LP shaft and feeding it to HP shaft which can lead to the removal of the bleeding system which in turn reduces weight and fuel consumption and help to overcome engine instability issues. Fuel consumption can be decreased by decreasing inconsistent thrust with the aircraft mission for flight and ground idle settings.
Technical Paper

Port Injection of Water into a DI Hydrogen Engine

2015-04-14
2015-01-0861
Hydrogen fueled internal combustion engines have potential for high thermal efficiencies; however, high efficiency conditions can produce high nitrogen oxide emissions (NOx) that are challenging to treat using conventional 3-way catalysts. This work presents the results of an experimental study to reduce NOx emissions while retaining high thermal efficiencies in a single-cylinder research engine fueled with hydrogen. Specifically, the effects on engine performance of the injection of water into the intake air charge were explored. The hydrogen fuel was injected into the cylinder directly. Several parameters were varied during the study, including the amount of water injected into the intake charge, the amount of fuel injected, the phasing of the fuel injection, the number of fuel injection events, and the ignition timing. The results were compared with expectations for a conventionally operated hydrogen engine where load was controlled through changes in equivalence ratio.
Technical Paper

MMLV: Automatic Transmission Lightweighting

2015-04-14
2015-01-1240
This paper details the lightweighting efforts of the Ford Research & Advanced Transmission team as part of the Multi Material Lightweight Vehicle Project. The Multi Material Lightweight Vehicle (MMLV) developed by Magna International and Ford Motor Company is a result of a US Department of Energy project DE-EE0005574. The project demonstrates the lightweighting potential of a five passenger sedan, while maintaining vehicle performance and occupant safety. Prototype vehicles were manufactured and limited full vehicle testing was conducted. The Mach-I vehicle design, comprised of commercially available materials and production processes, achieved a 364kg (23.5%) full vehicle mass reduction, enabling the application of a 1.0-liter three cylinder engine resulting in a significant environmental benefits and fuel consumption reduction.
Technical Paper

Stochastic Knock Detection, Control, Software Integration, and Evaluation on a V6 Spark-Ignition Engine under Steady-State Operation

2014-04-01
2014-01-1358
The ability to operate a spark-ignition (SI) engine near the knock limit provides a net reduction of engine fuel consumption. This work presents a real-time knock control system based on stochastic knock detection (SKD) algorithm. The real-time stochastic knock control (SKC) system is developed in MATLAB Simulink, and the SKC software is integrated with the production engine control strategy through ATI's No-Hooks. The SKC system collects the stochastic knock information and estimates the knock level based on the distribution of knock intensities fitting to a log-normal (LN) distribution. A desired knock level reference table is created under various engine speeds and loads, which allows the SKC to adapt to changing engine operating conditions. In SKC system, knock factor (KF) is an indicator of the knock intensity level. The KF is estimated by a weighted discrete FIR filter in real-time.
Technical Paper

Information on the Aromatic Structure of Internal Diesel Injector Deposits From Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS)

2014-04-01
2014-01-1387
The nature of internal diesel injector deposits (IDID) continues to be of importance to the industry, with field problems such as injector sticking, loss of power, increased emissions and fuel consumption being found. The deposits have their origins in the changes in emission regulations that have seen increasingly severe conditions experienced by fuels because of high temperatures and high pressures of modern common rail systems and the introduction of low sulphur fuels. Furthermore, the effect of these deposits is amplified by the tight engineering tolerances of the moving parts of such systems. The nature and thus understanding of such deposits is necessary to both minimising their formation and the development of effective diesel deposit control additives (DCA).
Technical Paper

Reducing Energy Losses from Automotive Engine Lubricants by Thermal Isolation of the Engine Mass

2014-04-01
2014-01-0672
The thermal efficiency of an internal combustion engine at steady state temperatures is typically in the region of 25-35%[1]. In a cold start situation, this reduces to be between 10% and 20% [2]. A significant contributor to the reduced efficiency is poor performance by the engine lubricant. Sub optimal viscosity resulting from cold temperatures leads to poor lubrication and a subsequent increase in friction and fuel consumption. Typically, the engine lubricant takes approximately twenty minutes [3] to reach steady state temperatures. Therefore, if the lubricant can reach its steady state operating temperature sooner, the engine's thermal efficiency will be improved. It is hypothesised that, by decoupling the lubricant from the thermal mass of the surrounding engine architecture, it is possible to reduce the thermal energy loss from the lubricant to the surrounding metal structure in the initial stages of warm-up.
Journal Article

Power Management of Hybrid Electric Vehicles based on Pareto Optimal Maps

2014-04-01
2014-01-1820
Pareto optimal map concept has been applied to the optimization of the vehicle system control (VSC) strategy for a power-split hybrid electric vehicle (HEV) system. The methodology relies on an inner-loop optimization process to define Pareto maps of the best engine and electric motor/generator operating points given wheel power demand, vehicle speed, and battery power. Selected levels of model fidelity, from simple to very detailed, can be used to generate the Pareto maps. Optimal control is achieved by applying Pontryagin's minimum principle which is based on minimization of the Hamiltonian comprised of the rate of fuel consumption and a co-state variable multiplied by the rate of change of battery SOC. The approach delivers optimal control for lowest fuel consumption over a drive cycle while accounting for all critical vehicle operating constraints, e.g. battery charge balance and power limits, and engine speed and torque limits.
Technical Paper

Direct In-cylinder Injection of Water into a PI Hydrogen Engine

2013-04-08
2013-01-0227
Injecting liquid water into a fuel/air charge is a means to reduce NOx emissions. Such strategies are particularly important to hydrogen internal combustion engines, as engine performance (e.g., maximum load) can be limited by regulatory limits on NOx. Experiments were conducted in this study to quantify the effects of direct injection of water into the combustion chamber of a port-fueled, hydrogen IC engine. The effects of DI water injection on NOx emissions, load, and engine efficiency were determined for a broad range of water injection timing. The amount of water injected was varied, and the results were compared with baseline data where no water injection was used. Water injection was a very effective means to reduce NOx emissions. Direct injection of water into the cylinder reduced NOx emissions by 95% with an 8% fuel consumption penalty, and NOx emissions were reduced by 85% without any fuel consumption penalty.
Journal Article

The Effect of Piston Cooling Jets on Diesel Engine Piston Temperatures, Emissions and Fuel Consumption

2012-04-16
2012-01-1212
A Ford 2.4-liter 115PS light-duty diesel engine was modified to allow solenoid control of the oil feed to the piston cooling jets, enabling these to be switched on or off on demand. The influence of the jets on piston temperatures, engine thermal state, gaseous emissions and fuel economy has been investigated. With the jets switched off, piston temperatures were measured to be between 23 and 88°C higher. Across a range of speed-load points, switching off the jets increased engine-out emissions of NOx typically by 3%, and reduced emissions of CO by 5-10%. Changes in HC were of the same order and were reductions at most conditions. Fuel consumption increased at low-speed, high-load conditions and decreased at high-speed, low-load conditions. Applying the results to the NEDC drive cycle suggests active on/off control of the jets could reduce engine-out emissions of CO by 6%, at the expense of a 1% increase in NOx, compared to the case when the jets are on continuously.
Journal Article

An Assessment of Two Piston Bowl Concepts in a Medium-Duty Diesel Engine

2012-04-16
2012-01-0423
Two combustion systems were developed and optimized for an engine for a power cylinder of 0.8-0.9L/cylinder. The first design was a re-entrant bowl concept which was based on the combustion system of a smaller engine with roughly 0.5L/cylinder. The second design was a chamfered bowl concept, a variant of a reentrant bowl that deliberately splits fuel between the bowl and the squish region. For each combustion system concept, nozzle tip protrusion, swirl, and nozzle configuration (number of holes, nozzle flow, and spray angle) were optimized. Several similarities between combustion system concepts were noted, including the optimal swirl and number of holes. The resulting optimums for each concept were compared. The chamfered combustion system was found to have better part-load emissions and fuel consumption tradeoffs. Full load performance was similar at low speed between the two combustion systems, but the reentrant combustion system had advantages at high engine speed and load.
Technical Paper

Internal combustion engine calibration teaching by Stand Alone System.

2010-10-06
2010-36-0346
Internal combustion engine calibration teaching by Stand Alone System. This paper illustrates a teaching methodology for technical students of internal combustion engine calibration, by stand alone engine control unit with variable ignition and fuel injection time. Using a system named HIS (Stand alone Electronic Control Unit), to change the engine parameters, as fuel injection time and ignition time, the students can optimize fuel consumption, performance and exhaust emission. The tests are developed using the DOE (design of experiments) technique of artificial intelligence.
Technical Paper

Engine Reliability Through Infant Mortality Mitigation: Literature Review

2010-10-06
2010-36-0049
Internal combustion engines are designed to meet the high power, low fuel consumption and also, low exhaust emissions. The engine running conditions is valid the concept that, the expectative is very high because of the variety of operating conditions like cold start, frequent start and stop, time high speed and load, traditional gasoline, mix of gasoline and alcohol and finally, alcohol fuel only. Considering such demand, this paper explains the relationship between the reliability bathtub curve, specifically the "Infant Mortality" portion. The bathtub curve describes failure rate as a function of time. The "Infant Mortality" portion of the curve is the initial section for which the failure (death) rate decreases with time (age). In general, these problems are related to manufacturing aspects or poor design definitions. With development of technology, hard failures, the ones that cause dependability, are becoming rare.
Technical Paper

Constraints on Fuel Injection and EGR Strategies for Diesel PCCI-Type Combustion

2008-04-14
2008-01-1327
An experimental study has been carried out to explore what limits fuel injection and EGR strategies when trying to run a PCCI-type mode of combustion on an engine with current generation hardware. The engine is a turbocharged V6 DI diesel with (1600 bar) HPCR fuel injection equipment and a cooled external EGR system. The variables examined have been the split and timings of fuel injections and the level of EGR; the responses investigated have been ignition delay, heat release, combustion noise, engine-out emissions and brake specific fuel consumption. Although PCCI-type combustion strategies can be effective in reducing NOx and soot emissions, it proved difficult to achieve this without either a high noise or a fuel economy penalty.
Technical Paper

Impact of Engine Operating Conditions on Low-NOx Emissions in a Light-Duty CIDI Engine Using Advanced Fuels

2002-10-21
2002-01-2884
The control of NOx emissions is the greatest technical challenge in meeting future emission regulations for diesel engines. In this work, a modal analysis was performed for developing an engine control strategy to take advantage of fuel properties to minimize engine-out NOx emissions. This work focused on the use of EGR to reduce NOx while counteracting anticipated PM increases by using oxygenated fuels. A DaimlerChrysler OM611 CIDI engine for light-duty vehicles was controlled with a SwRI Rapid Prototyping Electronic Control System. Engine mapping consisted of sweeping parameters of greatest NOx impact, starting with OEM injection timing (including pilot injection) and EGR. The engine control strategy consisted of increased EGR and simultaneous modulation of both main and pilot injection timing to minimize NOx and PM emission indexes with constraints based on the impact of the modulation on BSFC, Smoke, Boost and BSHC.
Technical Paper

Research and Development of Controlled Auto-Ignition (CAI) Combustion in a 4-Stroke Multi-Cylinder Gasoline Engine

2001-09-24
2001-01-3608
Controlled Auto-Ignition (CAI) combustion has been achieved in a production type 4-stroke multi-cylinder gasoline engine. The engine was based on a Ford 1.7L Zetec-SE 16V engine with a compression ratio of 10.3, using substantially standard components modified only in design dimensions to control the gas exchange process in order to significantly increase the trapped residuals. The engine was also equipped with Variable Cam Timing (VCT) on both the intake and exhaust camshafts. It was found that the largely increased trapped residuals alone were sufficient to achieve CAI in this engine and with VCT, a range of loads between 0.5 and 4 bar BMEP and engine speeds between 1000 and 3500 rpm were mapped for CAI fuel consumption and exhaust emissions. The measured CAI results were compared with those of Spark Ignition (SI) combustion in the same engine but with standard camshafts at the same speeds and loads.
Technical Paper

Characterisation of DISI Emissions and Fuel Economy in Homogeneous and Stratified Charge Modes of Operation

2001-09-24
2001-01-3671
An experimental study of the performance of a reverse tumble, DISI engine is reported. Specific fuel consumption and engine-out emissions have been investigated for both homogeneous and stratified modes of fuel injection. Trends in performance with varying AFR, EGR, spark and injection timings have been explored. It is shown that neural networks can be trained to describe these trends accurately for even the most complex case of stratified charge operation with exhaust gas recirculation.
Technical Paper

Development of a Desulfurization Strategy for a NOx Adsorber Catalyst System

2001-03-05
2001-01-0510
The aggressive reduction of future diesel engine NOx emission limits forces the heavy- and light-duty diesel engine manufacturers to develop means to comply with stringent legislation. As a result, different exhaust emission control technologies applicable to NOx have been the subject of many investigations. One of these systems is the NOx adsorber catalyst, which has shown high NOx conversion rates during previous investigations with acceptable fuel consumption penalties. In addition, the NOx adsorber catalyst does not require a secondary on-board reductant. However, the NOx adsorber catalyst also represents the most sulfur sensitive emissions control device currently under investigation for advanced NOx control. To remove the sulfur introduced into the system through the diesel fuel and stored on the catalyst sites during operation, specific regeneration strategies and boundary conditions were investigated and developed.
Technical Paper

Study of a Stratified-Charge DISI Engine with an Air-Forced Fuel Injection System

2000-06-19
2000-01-2901
A small-bore 4-stroke single-cylinder stratified-charge DISI engine using an air-forced fuel injection system has been designed and tested under various operating conditions. At light loads, fuel consumption was improved by 16∼19% during lean, stratified-charge operation at an air-fuel ratio of 37. NOx emissions, however, were tripled. Using EGR during lean, stratified-charge operation significantly reduced NOx emissions while fuel consumption was as low as the best case without EGR. It was also found that combustion and emissions near the lean limit were a strong function of the combination of injection and spark timings, which affect the mixing process. Injection pressure, air injection duration, and time delay between fuel and air injections also played a role. Generating in-cylinder air swirl motion slightly improved fuel economy.
Technical Paper

Customer Fuel Consumption – The Vehicle Data Bus as Real–World Information Source

2000-03-06
2000-01-1337
Road to rig problems exist as long as vehicles are being tested. Many approaches and methods exist to produce test cycles for rigs or test tracks, in order to produce viable results for the generation of statements concerning such crucial aspects as durability and fuel consumption. Modern model strategies again demand shorter–than–ever development periods, whilst meeting better–than–ever the needs and demands of special target groups. Therefore, the testing methods must also be refined, in order to gain a closer correlation to the customer's vehicle deployment. The approach introduced here makes use of real–world customer data for obtaining a closer look at how the vehicle is used by different customer groups, in different countries. The data is collected by small and unobtrusive dataloggers installed in customer vehicles. As these customers are using their own vehicles in everyday life, being unaware of the acquisition process, a database of real customer usage is generated.
Technical Paper

Evaluation of Turbocharger Power Assist System Using Optimal Control Techniques

2000-03-06
2000-01-0519
In the paper we employ numerical optimal control techniques to define the best transient operating strategy for a turbocharger power assist system (TPAS). A TPAS is any device capable of bi-directional energy transfer to the turbocharger shaft and energy storage. When applied to turbocharged diesel engines, the TPAS results in significant reduction of the turbo-lag. The optimum transient strategy is capable of improving the vehicle acceleration performance with no deterioration in smoke emissions. These benefits can be attained even if the net energy contribution by the TPAS during the acceleration interval is zero, i.e., all energy is re-generated and returned back to the energy storage by the end of the acceleration interval. At the same time the total fuel consumption during the acceleration interval may be reduced.
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