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Event
2014-10-20
This session covers topics regarding new CI and SI engines and components. This includes analytical, experimental, and computational studies covering hardware development as well as design and analysis techniques.
Event
2014-10-20
Mixed modes with both flame propagation and slow auto ignition. Distinct from SI knock: autoignition is desired and will not ruin the engine. Papers describing experiments and test data, simulation results focused on applications, fuel/additive effects, and SACI mode change are invited and will be placed in appropriate sub-sessions. Papers with an emphasis on the modeling aspects of combustion are encouraged to be submitted into PFL 110 or PFL120 modeling sessions.
Event
2014-10-20
This session focuses on technologies such as advanced and partially mixed combustion, cooled EGR boosting, ignition and direct injection technologies, pressure boosting, intelligent combustion, thermal efficiency, fully variable valvetrains, and other new and developing technologies. Papers focused on waste heat recovery technologies should be submitted to HX102/103.
Event
2014-10-20
Separate sub-sessions cover zero-dimensional, one-dimensional, and quasi-dimensional models for simulation of SI and CI engines with respect to: engine breathing, boosting, and acoustics; SI combustion and emissions; CI combustion and emissions; fundamentals of engine thermodynamics; numerical modeling of gas dynamics; thermal management; mechanical and lubrication systems; system level models for controls; system level models for vehicle fuel economy and emissions predictions.
Event
2014-10-20
This session covers the Power Cylinder: piston, piston rings, piston pins, and connecting rods. The papers include information on reducing friction and increasing fuel economy, improving durability by understanding wear, and decreasing oil consumption and blow-by.
Training / Education
2014-09-29
Engines can and do experience failures in the field in a variety of equipment, vehicles, and applications. On occasion, a single vehicle type or equipment family will even experience multiple engine failures leading to the inevitable need to determine what the most likely cause of one or all of those failures was. This comprehensive seminar introduces participants to the methods and techniques used to determine the most likely cause of an individual engine or group of engine failures in the field. The seminar begins with a review of engine design architecture and operating cycles, integration of the engine into the vehicle itself, and finally customer duty cycles and operating environments. Special emphasis is placed on the number and type of subsystems that not only exist within the engine (diesel and gasoline) but are used to integrate the engine into the overall vehicle package. Following this review, participants learn about failure types, investigation techniques, inspection methods, and how to analyze the available evidence using their own knowledge of engine and vehicle operating characteristics to determine the most likely cause of an engine(s) failure.
Training / Education
2014-08-18
Public awareness regarding pollutants and their adverse health effects has created an urgent need for engineers to better understand the combustion process as well as the pollutants formed as by-products of that process. To effectively contribute to emission control strategies and design and develop emission control systems and components, a good understanding of the physical and mathematical principles of the combustion process is necessary. This seminar will bring issues related to combustion and emissions "down to earth," relying less on mathematical terms and more on physical explanations and analogies.
WIP Standard
2014-04-08
This SAE Information Report lists engine and laboratory tests for service fill engine oils which are associated with specifications and classifications established outside of North America. These specifications and classifications include those developed prior to June 1, 2006 June 1, 2001, by International Technical Societies as well as individual original equipment manufacturers. The information contained within this report applies to engine oils utilized in gasoline and diesel powered automotive vehicles.
Event
2014-04-08
Advances in automotive gasoline engine technology will continue to play a pivotal role in the reduction of greenhouse gases. A key enabler for improved efficiency is increased power density, but this is restrained by the limits of knock and pre-ignition. Experts will share their experience and thoughts on technologies that can be collectively combined to push beyond the current knock/pre-ignition ceiling. They will also examine how these technologies contribute to greater engine efficiency.
WIP Standard
2014-04-04
This SAE Information Report reviews the various physical and chemical properties of engine oils and provides references to test methods and standards used to measure these properties. It also includes general references on the subject of engine oils, base stocks, and additives.
Technical Paper
2014-04-01
Hu Li, Ahmad Khalfan, Gordon Andrews
A SI probe car, defined here as a normal commercial car equipped with GPS, in-vehicle FTIR tailpipe emission measurement and real time fuel consumption measurement systems, and temperature measurements, was used for measuring greenhouse gas emissions including CO2, N2O and CH4 under real world urban driving conditions. The vehicle used was a EURO4 emission compliant SI car. Two real world driving cycles/routes were designed and employed for the tests, which were located in a densely populated area and a busy major road representing a typical urban road network. Eight trips were conducted at morning rush hours, day time non-peak traffic periods and evening off peak time respectively. The aim is to investigate the impacts of traffic conditions such as road congestion, grade and turnings on fuel consumption, engine thermal efficiency and emissions. The time aligned vehicle moving parameters with fuel consumption and emission data enabled the micro-analysis of the correlations between these parameters.
Technical Paper
2014-04-01
Sunil Pathak, Y R Singh, Vineet Sood, S K Singal, Salim Abbasbhai Channiwala
Abstract The main objectives this paper is two-fold. First, the paper highlights the role of good road and traffic infrastructure for improving the on-road fuel economy of vehicle. Second, it investigate the dynamic driving parameters like positive tractive power level, modes of driving and velocity acceleration envelopes, affecting the on road energy demand and fuel economy. In this study, the gasoline passenger car was driven about 260 km each on two different intercity highways by same driver and at same load. The road and traffic condition of two highways was chosen entirely different, one highway as well organized and other as poorly organized. The fuel consumption and speed time trace were captured using on-board equipments in the field run. The average on road fuel economy was observed as 16.65 km/l (around 18% higher) for well organized highway as compared to 14.13 km/l for other highway. The analysis of speed and time trace for well organized and dis- organized highway trip for positive tractive power level distribution is summarized as: The gasoline vehicles are most fuel efficient in the mid power range and less efficient in the low and high power level range.
Technical Paper
2014-04-01
Federico Millo, Luciano Rolando, Enrico Pautasso, Emanuele Servetto
Abstract In this paper a novel approach to mimic through numerical simulation Cycle-to-Cycle Variations (CCV) of the combustion process of Spark Ignition (SI) engines is described. The proposed methodology allows to reproduce the variability in combustion which is responsible for knock occurrence and thus to replicate the stochastic behavior of this abnormal combustion phenomenon. On the basis of the analysis of a comprehensive database of experimental data collected on a typical European downsized and turbocharged SI engine, the proposed approach was demonstrated to be capable to replicate in the simulation process the same percentage of knocking cycles experimentally measured in light-knock conditions, after a proper calibration of the Kinetics-Fit (KF), a new phenomenological knock model which was recently developed by Gamma Technologies. Finally, the capability of the proposed methodology, coupled with the usage of the KF knock model, to correctly identify the Knock Limited Spark Advance (KLSA) on the basis both of the CCV-replicating model and of a more traditional average-cycle simulation was assessed over a wide range of different operating conditions, thus confirming its reliability and robustness.
Technical Paper
2014-04-01
Momir Sjeric, Darko Kozarac, Ivan Taritas
Abstract The paper presents modeling of cycle-to-cycle variations (CCV) of a SI engine by using the modified cycle-simulation model. The presented research has been performed on CFR engine fueled by gasoline. Experimental in-cylinder pressure traces of 300 cycles have been processed for several operating points representing the spark sweep which captured the operating points with low and high CCV. The cycle-simulation model applied in this study uses significantly improved turbulence and combustion model that have been implemented into the cycle-simulation code. Developed k-ε turbulence model and the quasi-dimensional combustion model based on the fractal theory have been applied. New quasi-dimensional ignition model was developed and integrated into the fractal combustion model in order to simulate the early flame kernel growth including the detailed modeling of spark plug geometry, electric spark phenomenon, heat transfer, in-cylinder flow around spark plug and the flame kernel interaction with the turbulence.
Technical Paper
2014-04-01
Vishwajith Bhat, Bhaskar Tamma
Abstract Phenomenological flame propagation model is critical for predicting performance and emissions of spark ignition (SI) engines. A multi-zone phenomenological model offers better accuracy in predicting the emission trends. Hence, in the present work, a multi-zone phenomenological SI flame combustion model is formulated and validated with engine data from published literature. The formulation includes turbulence, combustion, flame propagation, flame geometry interaction with solid walls, gas-to-wall heat transfer, CO and NO emissions from burnt zones and HC emission from quench layer. A knock model has also been implemented. The key contributions are implementation of k-epsilon turbulence model which takes care of contribution from squish/swirl/combustion, predictive multi-zone flame propagation model and a decisive zoning scheme based on percentage of fuel burnt. Validation has been carried out for three different fuels (Iso-octane, Gasoline and Natural Gas) for engine speeds ranging from 1500-4000 rpm establishing the model capabilities to respond to different fuels and engine speed.
Technical Paper
2014-04-01
Jiri Hvezda
Abstract The paper introduces a recently developed toolset to be implemented into the complex simulation codes for internal combustion engines to treat the calculations dealing with a high-pressure part of the thermodynamic cycle in a four-stroke spark ignition engine. This multi-zone simulating tool works on the basis of a simple quasi-dimensional method reflecting the real combustion chamber geometry and uses a specific approach to describe the species chemical transformation during combustion. Here a standard kinetic scheme is combined adaptively with a flexible method for chemical equilibrium in the cases of abnormally fast chemical reactions to improve the numerical performance of the equation system. Real 3-D combustion chamber geometry is taken into account by means of geometrical characteristics created in advance. A newly generalized tool providing these data is presented here. The new code is also able to work in predictive or inverse mode. The selected results regarding these two algorithms are mentioned at the end.
Technical Paper
2014-04-01
Stefano Fontanesi, Elena Severi, Daniela Siano, Fabio Bozza, Vincenzo De Bellis
In the present paper, two different methodologies are adopted and critically integrated to analyze the knock behavior of a last generation small size spark ignition (SI) turbocharged VVA engine. Particularly, two full load operating points are selected, exhibiting relevant differences in terms of knock proximity. On one side, a knock investigation is carried out by means of an Auto-Regressive technique (AR model) to process experimental in-cylinder pressure signals. This mathematical procedure is used to estimate the statistical distribution of knocking cycles and provide a validation of the following 1D-3D knock investigations. On the other side, an integrated numerical approach is set up, based on the synergic use of 1D and 3D simulation tools. The 1D engine model is developed within the commercial software GT-Power™. It is used to provide time-varying boundary conditions (BCs) for the 3D code, Star-CD™. Particularly, information between the two simulation tools are at first exchanged under motored conditions to tune an “in-house developed” turbulence sub-model included in the 1D software. 1D results are then validated against the experimental data under fired full load operations, by employing a further “in-house developed” combustion sub-model.
Technical Paper
2014-04-01
Fabio Bozza, Vincenzo De Bellis, Alfredo Gimelli, Massimiliano Muccillo
It is commonly recognized that the paths for improving fuel consumption (BSFC) in a spark-ignition engine at part-load require more advanced valve actuation strategies, which largely affect the pumping work. Since several years, many different solutions have been proposed, characterized by different levels of complexity, effectiveness, and cost. Valve systems currently available on the market allow for variable phasing (VVT - Variable Valve Timing), and/or lift (VVA - Variable Valve Actuation). Usually VVT devices are applied on intake and exhaust camshafts, in the “phased” or “unphased” configuration, as well. VVA devices are instead commonly mounted on the intake camshaft. More recent VVA systems also allow for a double intake valve lift during a single engine cycle (multi-lift), or may include a small intake pre-lift during the exhaust stroke. The latter solutions may determine further BSFC reductions. Alternatively, an external-EGR circuit can be considered, as well. Each system introduces additional parameters to the standard engine control variables (throttle opening, spark advance, waste-gate valve opening in turbocharged engines).
Technical Paper
2014-04-01
Hadi Adibi asl, Ramin Masoudi, Roydon Fraser, John McPhee
Abstract This paper presents a math-based spark ignition (SI) engine model for fast simulation with enough fidelity to predict in-cylinder thermodynamic properties at each crank angle. The quasi-dimensional modelling approach is chosen to simulate four-stroke operation. The combustion model is formulated based on two-zone combustion theory with a turbulent flame propagation model [1]. Cylinder design parameters such as bore and stroke play an important role to achieve higher performance (e.g. power) and reduce undesirable in-cylinder phenomenon (e.g. knocking). A symbolic sensitivity analysis is used to study the effect of the design parameters on the SI engine performance. We used the symbolic Maple/MapleSim environment to obtain highly-optimized simulation code [3]. It also facilitates a sensitivity analysis that identifies the critical parameters for design and control purposes. Among various schemes used in the sensitivity analysis of dynamical systems, internal differentiation is used in this research project due to its reliability and robustness [4].
Technical Paper
2014-04-01
Hung Nguyen Ba, Ocktaeck Lim, Norimasa Iida
Abstract A simulation study was conducted to examine the transition from SI combustion to HCCI combustion in a two-stroke free piston engine fuelled with propane. Operation of the free piston engine was simulated based on the combination of three mathematical models including a dynamic model, a linear alternator model and a thermodynamic model. The dynamic model included an analysis of the piston motion, based on Newton's second law. The linear alternator model included an analysis of electromagnetic force, which was considered to be a resistance force for the piston motion. The thermodynamic model was used to analysis thermodynamic processes in the engine cycle, including scavenging, compression, combustion, and expansion processes. Therein, the scavenging process was assumed to be a perfect process. These mathematical models were combined and solved by a program written in Fortran. To validate the mathematical models, the simulation results were compared with experimental data in the SI mode.
Technical Paper
2014-04-01
Ramin Masoudi, Hadi Adibi asl, Nasser Lashgarian Azad, John McPhee
Abstract Parameter identification of a math-based spark-ignition engine model is studied in this paper. Differential-algebraic equations governing the dynamic behavior of the engine combustion model are derived using a quasi-dimensional modelling scheme. The model is developed based on the two-zone combustion theory with turbulent flame propagation through the combustion chamber [1]. The system of equations includes physics-based equations combined with the semi-empirical Wiebe function. The GT-Power engine simulator software [2], a powerful tool for design and development of engines, is used to extract the reference data for the engine parameter identification. The models is GT-Power are calibrated and validated with experimental results; thus, acquired data from the software can be a reliable reference for engine validation purposes. Homotopy optimization procedure, in which the original differential equations are modified by coupling the experimental data to the mathematical model using a homotopy parameter and gains, has been utilized in this work to obtain a global minimum for the parameters giving the best match to experiments [3].
Technical Paper
2014-04-01
Rasoul Salehi, Aria Alasty, Gholam-Reza Vossoughi
Proper operation of an internal combustion engine is required by demands of a vehicle driver and governmental legislations. Therefore it is necessary to monitor, within an online technique, the engine and detect any fault which disrupts its normal operation. In this paper, the air-charge path, as a key element in a turbocharged engine, is monitored for an air leakage fault. At first, a robust algorithm to estimate unmeasured turbocharger rotational speed is presented. The sliding mode methodology is used to design the estimator which is shown to be robust to the compressor modeling uncertainties. The estimation error from the sliding mode observer (SMO) is then used to detect abnormal behavior of the turbocharger along with the engine due to a leakage fault in the air-charge path. Experimental results from a modern turbocharged SI engine indicate the designed monitoring technique is able to detect a leakage fault, of 7 mm or higher sizes, in the air-charge path.
Technical Paper
2014-04-01
Wei Luo, Bo Chen, Jeffrey Naber, Chris Glugla
Abstract 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. Both offline simulation and engine dynamometer test results show that stochastic knock control with fixed length of finite impulse response (FIR) filter has slow and excessive retard issue when a significant knock event happens.
Technical Paper
2014-04-01
Enrico Corti, Claudio Forte, Nicolo Cavina, Giorgio Mancini, Vittorio Ravaglioli
Combustion phasing is crucial to achieve high performance and efficiency: for gasoline engines control variables such as Spark Advance (SA), Air-to-Fuel Ratio (AFR), Variable Valve Timing (VVT), Exhaust Gas Recirculation (EGR), Tumble Flaps (TF) can influence the way heat is released. The optimal control setting can be chosen taking into account performance indicators, such as Indicated Mean Effective Pressure (IMEP), Brake Specific Fuel Consumption (BSFC), pollutant emissions, or other indexes inherent to reliability issues, such as exhaust gas temperature, or knock intensity. Given the high number of actuations, the calibration of control parameters is becoming challenging. Many different approaches can be used to reach the best calibration settings: Design Of Experiment (DOE) is a common option when many parameters influence the results, but other methodologies are in use: some of them are based on the knowledge of the controlled system behavior, by means of models that are identified during the calibration process.
Technical Paper
2014-04-01
Kevin Cedrone, Wai K. Cheng
The engine and its exhaust flow behaviors are investigated in a turbo-charged gasoline direct injection engine under simulated cold-fast-idle condition. The metrics of interest are the exhaust sensible and chemical enthalpy flows, and the exhaust temperature, all of which affect catalyst light off time. The exhaust sensible enthalpy flow is mainly a function of combustion phasing; the exhaust chemical enthalpy flow is mainly a function of equivalence ratio. High sensible and chemical enthalpy flow with acceptable engine stability could be obtained with retarded combustion and enrichment. When split injection is employed with one early and one later and smaller fuel pulse, combustion retards with early secondary injection in the compression stroke but advances with late secondary injection. Comparing gasoline to E85, the latter produces a lower exhaust temperature because of charge cooling effect and because of a faster combustion.
Technical Paper
2014-04-01
Justin E. Ketterer, Wai K. Cheng
Abstract Particulate emissions from a production gasoline direct injection spark ignition engine were studied under a typical cold-fast-idle condition (1200 rpm, 2 bar NIMEP). The particle number (PN) density in the 22 to 365 nm range was measured as a function of the injection timing with single pulse injection and with split injection. Very low PN emissions were observed when injection took place in the mid intake stroke because of the fast fuel evaporation and mixing processes which were facilitated by the high turbulent kinetic energy created by the intake charge motion. Under these conditions, substantial liquid fuel film formation on the combustion chamber surfaces was avoided. PN emissions increased when injection took place in the compression stroke, and increased substantially when the fuel spray hit the piston. A conceptual model was established for the particulate matter (PM) formation process in which PM is formed by pyrolysis after the normal premixed flame passage in fuel rich plumes originating from liquid films on the cylinder walls.
Technical Paper
2014-04-01
Nick Polcyn, Ming-Chia Lai, Po-I Lee
Abstract The need for using alternative fuel sources continues to grow as industry looks towards enhancing energy security and lowering emissions levels. In order to capture the potential of these megatrends, this study focuses on the relationship between ignition energy, thermal efficiency, and combustion stability of a 0.5 L single cylinder engine powered by compressed natural gas (CNG) at steady state operation. The goal of the experiment was to increase ignition energy at fixed lambda values to look for gains in thermal efficiency. Secondly, a lambda sweep was performed with criteria of maintaining a 4% COVIMEP by increasing the ignition energy until an appropriate threshold for stable combustion was found. The engine performance was measured with a combustion analysis system (CAS), to understand the effects of thermal efficiency and combustion stability (COVIMEP). Emissions of the engine were measured with an FTIR. The engine was instrumented with visualization equipment to capture real-time combustion images.
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