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The Virtual Engine Development for Enhancing the Compression Ratio of DISI-Engines by Means of Water Injection and Variable Valve Timing

FKFS-Antonino Vacca, Francesco Cupo, Marco Chiodi, Michael Bargende
Ford Werke GmbH-Oliver Berkemeier, Maziar Khosravi
  • Technical Paper
  • 2020-37-0010
To be published on 2020-06-23 by SAE International in United States
With the aim of significantly reducing emissions, while keeping CO2 production under control, gasoline engines are faced with a new challenge to survive the constraints imposed by the RDE cycles. Current downsized engines are developed with the most recent techniques for increasing efficiency, such as high direct injection pressure, selective valve actuation, variable turbine geometry, and innovative thermal management system. The factor limiting their further step towards enhanced efficiency is the onset of abnormal combustion process. Therefore the challenge for the further boost of modern engine efficiency is the improvement of the combustion process. Different combustion technics such as HCCI and the employment of pre-chamber have been investigated, but the possibility of effectively use them in a wide range of the engine map, by fulfilling at the same time the needing of fast load control are still limiting their dissemination. For these reasons the technologies for improving the characteristics of a standard combustion process are still deeply investigated. Among these water injection in combination with either early or late intake valve closing offers the possibility…
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The Use of Piezoelectric Washers for Feedback Combustion Control

University of Bologna-Enrico Corti, Marco Abbondanza, Fabrizio Ponti, Lorenzo Raggini
  • Technical Paper
  • 2020-01-1146
To be published on 2020-04-14 by SAE International in United States
The use of piezoelectric cylinder pressure sensors is very popular during engine testing, but cylinder pressure information is becoming mandatory also in several on-board applications, where Low Temperature Combustion (LTC) approaches require a feedback control of combustion, due to poor combustion stability and the risk of knock or misfire.Several manufacturers showed the capability to develop solutions for cylinder pressure sensing in on-board automotive and aeronautical applications, and some of them have been patented. The most straight-forward approach seems the application of a piezo-electric washer as a replacement of the original part equipping the spark plug; the injector could also be used to transfer the cylinder pressure information to the piezoelectric quartz, in diesel or Gasoline Direct Injections (GDI) engines.The paper describes the features of signals acquired using piezoelectric washers, discussing possible applications, highlighting the factors which impact the sensors accuracy, and proposing algorithms to compensate potential errors in the evaluation of combustion metrics. The sensors have been first tested on a press, then in two different gasoline engines: a naturally aspirated V12 and a turbocharged…
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Methodology to standardize and improve the calibration process of a 1D model of a GTDI engine

Universitat Politècnica de València-Jose Serrano, Hector Climent, Roberto Navarro, David González-Domínguez
  • Technical Paper
  • 2020-01-1008
To be published on 2020-04-14 by SAE International in United States
Modeling techniques are one of most useful tools during the first stages of the ICE design. They allow to analyze and predict the entire engine performance, reduce costs and resources and surely accelerate its development. For that purpose, a former and suitable calibration process is needed in order to attain reliable and robust models. Therefore, in this work a methodology is proposed to standardize and improve the calibration of a whole 1D engine model. In this case, it has been applied to a gasoline, turbocharged, direct injection engine with variable nozzle turbine and variable valve timing technologies. This calibration procedure is mainly distinguished by insulating the different engine parts, decoupling the turbocharger, using PI controls to find fitting parameters and checking and validating mean and instantaneous variables related to flow conditions inside the engine. Moreover, it requires experimental data and a previous combustion analysis of some steady operating points. The methodology is completed with the determination of fitting correlations to estimate heat losses and pressure drops in engine systems. It also includes the training of…
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Prediction of Fuel Maps in Variable Valve Timing Spark Ignited Gasoline Engines Using Kriging Metamodels

Oakland University-Ali Tafreshi, Zissimos Mourelatos
  • Technical Paper
  • 2020-01-0744
To be published on 2020-04-14 by SAE International in United States
Creating a fuel map for simulation of an engine with Variable Valve Actuation (VVA) can be computationally demanding. Design of Experiments (DOE) and metamodeling is one way to address this issue. In this paper, we introduce a sequential process to generate an engine fuel map using Kriging metamodels which account for different engine characteristics such as load and fuel consumption at different operating conditions. The generated map predicts engine output parameters such as fuel rate and load. We first create metamodels to accurately predict the Brake Mean Effective Pressure (BMEP), fuel rate, Residual Gas Fraction (RGF) and CA50 (Crank Angle for 50% Heat Release after top dead center). The last two quantities are used to ensure acceptable combustion. The metamodels are created sequentially to ensure acceptable accuracy is achieved with a small number of simulations. Two optimization problems are then solved using the developed metamodels, for full load and part load conditions, respectively. We demonstrate that the estimated fuel map is of high accuracy compared to the actual map. The map is obtained with about…
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Analysis of Cycle-to-Cycle Variation in a Port Injection Gasoline Engine by Simultaneous Measurement of Time Resolved PIV and PLIF

Chiba University-Tatsuya KUBOYAMA, Yasuo MORIYOSHI
Sustainable Engine Research Center Co., Ltd.-Satoshi HOKIMOTO
  • Technical Paper
  • 2019-32-0552
Published 2020-01-24 by Society of Automotive Engineers of Japan in Japan
Cycle-to-cycle variation (CCV) of combustion in low load operation is a factor that may cause various problems in engine operation. Variable valve timing and variable ignition timing are commonly used as a means to reduce this variation. However, due to mountability and cost constraints, these methods are not feasible for use in motorcycle engines. Therefore, development of an engine with minimal CCV without utilizing complicated mechanisms or electronic control is required. CCV of combustion may be caused by fluctuations in in-cylinder flow, air-fuel mixture, temperature, residual gas and ignition energy. In this study, the relationship between CCV of combustion, in-cylinder flow fluctuation and air-fuel mixture fluctuation was the primary focus. In order to evaluate in-cylinder flow fluctuation, Time Resolved Particle Image Velocimetry (TR-PIV) technique was utilized. In addition, Planar Laser Induced Fluorescence (PLIF) technique was used to measure spatial distribution of the mixture. These two visualization techniques were used together to measure continuous combustion cycles. The fluctuation of net IMEP can be explained by the fluctuation of Turbulence Kinetic Energy (TKE) and fuel concentration. In…
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Flexible valve timing strategies for boosting a small four-stroke spark ignition engine performance

Automotive Engineering Centre (AEC), Universiti Malaysia Pah-M. Razali Hanipah, Akhtar Razul Razali
Faculty of Mechanical and Automotive Engineering Technology,-M. Haziq Adham Rosli
  • Technical Paper
  • 2019-32-0591
Published 2020-01-24 by Society of Automotive Engineers of Japan in Japan
Variable valve timing (VVT) technology has been successful in enhancing internal combustion (IC) engine performance. VVT offers an additional control on engine breathing so that the engine operating conditions may be tailored more precisely hence, output and performance are amplified. In this paper, an approach of boosting IC engine performance through flexible valve timing (FVT) is presented. A numerical baseline model was developed using onedimensional numerical simulation tool based on a 65cc four-stroke gasoline engine. The flow coefficient values of intake and exhaust ports were obtained from flow bench experiments. The baseline model was validated against specification from manufacturer and results from previous research. This model undergone performance tuning to obtain the power and torque curves for the whole engine speed range. Next, performance optimization was conducted through design of experiments (DoE) with the target of boosting the torque and power of the baseline model between 5 to 10% for the engine speed from 1,500 until 6,000rpm. This was obtained through the variation of intake and exhaust valves timing as well as maximum lift using…
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Study of the Variable Valve Timing Effects on Combustion Quality and Fuel Consumption of an Internal Combustion Engine

Mobility Technology Center – Federal University of Minas Ger-Augusto César Teixeira Malaquias, Nilton Antonio Diniz Netto, José Guilherme Coelho Baêta, Alysson Fernandes Teixeira, Sérgio Augusto Passos Costa
  • Technical Paper
  • 2019-36-0117
Published 2020-01-13 by SAE International in United States
The need for a constant evolution of internal combustion engines has encouraged the emergence of new alternatives for the minimization of pollutant emissions, fuel consumption and an increase of the overall performance. The coming years will be marked by the launch of increasingly efficient engines, given the current importance of sustainability in the means of transport. Despite the growing electrification of global mobility, research indicates that the ICE will continue to be the main source of automotive energy in the coming years and, therefore, the study of strategies aimed at optimizing its performance is and will continue to be relevant. In this sense, the purpose of this work is to study the effects of variable valve timing on the experimental calibration of an internal combustion engine intended for research. Different moments of opening and closing of both the intake and exhaust valves were analyzed so that the possible reductions in the specific fuel consumption and the combustion quality improvements could be studied in tests always aimed at maximizing the fuel conversion efficiency. The purpose was…
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Variable Camshaft Valve Timing and its Effects to Hydrous Ethanol (E100) Combustion during Engine Warm up Phase

Ford Motor Company Brazil-Gustavo C. Passarini, Marcos Fregoneze, Fernando Sarracini Júnior
  • Technical Paper
  • 2019-36-0147
Published 2020-01-13 by SAE International in United States
In-cylinder airflow has significant impact in mixture formation and burn in internal combustion engines. Exhaust valve closing retard and early intake valve opening have large contribution for the in-cylinder airflow. It may reduce pumping work (energy lost to pump exhaust gases out of the cylinder and to draw the fresh air-fuel mixture), hurt combustion stability due to the excess of residual gas in the combustion chamber or still contribute to cylinder scavenging, increasing the amount of fresh air resulting in higher burn efficiency and more work extracted from the cycle. Brazilian market has large Hydrous Ethanol fuel (E100) usage. Due to E100 fuel properties, the intake and exhaust valves opening and closing time must be carefully defined during the engine warm up phase to avoid negative effects on the combustion. The objective of this work is to analyze the effects in performance, combustion stability and emissions, of exhaust valve timing at different engine temperatures when using E100 fuel in a Ford 1.5L naturally aspirated 3-cylinder engine with Port Fuel Injection (PFI) and dual variable valve…
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Performance and Emissions of an Advanced Multi-Cylinder SI Engine Operating in Ultra-Lean Conditions

Renault SA-Cédric LIBERT
University of Naples “Federico II”-Fabio Bozza, Daniela Tufano, Enrica Malfi, Luigi Teodosio, Vincenzo De Bellis
Published 2019-09-09 by SAE International in United States
In this work the performance and noxious emissions of a prototype Spark Ignition (SI) engine, working in ultra-lean conditions, are investigated. It is a four-cylinder engine, having a very high compression ratio, and an active pre-chamber. The required amount of air is provided by a low-pressure variable geometry turbocharger, coupled to a high-pressure E-compressor. The engine is equipped with a variable valve timing device on the intake camshaft.The goal of this activity is to support the development and the calibration of the described engine, and to exploit the full potential of the ultra-lean concept. To this aim, a combustion model for a pre-chamber engine, set up and validated in a previous paper for a similar single-cylinder unit, is utilized. It is coupled to additional in-house developed sub-models, employed for the prediction of the in-cylinder turbulence, heat transfer, knock and pollutant emissions.Such a complex architecture, schematized in a commercial 1D modeling framework, presents several control parameters which have to be properly selected to maximize the engine efficiency and minimize the noxious emissions over its whole operating…
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A Process for an Efficient Heat Release Prediction at Multiple Engine Speeds and Valve Timings in the Early Stage of Gasoline Engine Development

LOGE AB-Andrea Matrisciano
Ricardo UK, Ltd.-Christian Rota, Richard Osborne, Kenan Mustafa
  • Technical Paper
  • 2019-24-0085
Published 2019-09-09 by SAE International in United States
The increasing need for cleaner and more efficient combustion systems has promoted a paradigm shift in the automotive industry. Virtual hardware and engine calibration screening at the early development stage, has become the most effective way to reduce the time necessary to bring new products to market. Virtual engine development processes need to provide realistic engine combustion rate responses for the entire engine map and for different engine calibrations. Quasi Dimensional (Q-D) combustion models have increasingly been used to predict engine performance at multiple operating conditions. The physics-based Q-D turbulence models necessary to correctly model the engine combustion rate within the Q-D combustion model framework are a computationally efficient means of capturing the effect of port and combustion chamber geometry on performance. A rigorous method of correlating the effect of air motion on combustion parameters such as heat release is required to enable novel geometric architectures to be assessed to deliver future improvements in engine performance.A previously assessed process using a combination of a 0-D combustion Stochastic Reactor Model (SRM), provided by LOGESoft, a 1-D…
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