Download or read book 1D SIMULATION OF DIRECT WATER INJECTION IN A SPARK IGNITED ENGINE written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book THE SETUP AND EXPERIMENTAL RESULTS OF DIRECT WATER INJECTION IN A SPARK IGNITED NATURAL GAS ENGINE AT VARYING COMPRESSION RATIOS written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : A production Kohler 8.5RES residential stand-by generator set (Genset) was selected as the platform for this study due to its availability, simplicity, and price point. The Genset consists of a spark ignited (SI) two cylinder vee style internal combustion engine (ICE) capable of running natural gas or propane fuel with a 8.5 kW generator connected directly to the engines crankshaft. This allows for electrical load to be applied to the generator which in turn loads the engine without the use of a conventional dynamometer. A water cooled fully adjustable electric resistive load bank allows for easy adjustment to the desired load point. The electrical power generated was measured to determine the ICE output power and calculate the fuel energy to electrical energy conversion efficiency. To allow for control of the engine while testing it was modified from its original carbureted form to a port fuel injected (PFI) configuration and the original fixed spark timing system was removed and replaced with a coil ignition system. An electronic throttle body (ETB) was fitted to allow adjustment to the incoming air flow. The cylinder heads were modified to allow for a production direct inject (DI) fuel injector which used to deliver water to the combustion chamber and an in cylinder pressure transducer for analysis of various combustion parameters. The genset and test cell were instrumented with low speed and high speed dataacquisition (DAQ) systems to monitor and capture data at the chosen operatingconditions. The high speed data captured by the DAQ was used in conjunction with anear real-time combustion analysis program which calculated and logged combustionparameters and allowed for optimization of spark timing at each test point. Low speed data including fuel consumption, air mass flow rat, water consumption, and electrical power generated along with other engine parameters were monitored and logged as well. The ICE was tested at three different compression ratios (CRs) by changing the pistons and then by removing material from the cylinder head to decrease the clearance volume. The CR that came from the engine supplier was the first to be tested, second a CR in the range of 10:1-11:1 was targeted, and the range of the third CR was 14:1-15:1. The exact values of the CRs tested were calculated once the modifications were complete and volume measurements could be made. The first CR tested was 8.5:1 which is what the engine comes with from the supplier, the second 10.75:1 after changing pistons, and the third 14.3:1 after removing material from the cylinder head. Baseline data was collected at the 8.5:1 CR using the factory the fuel and ignition system to be used for comparison. Once the fuel, spark, and ETB modifications were complete tests were conducted by varying the load from 0 kW to the maximum attainable load at each test condition in 1 kW increments while targeting a relative air-fuel ratio (lambda, λ) of 1.0 and a speed of 3600 rpm. Using the combustion analysis software the gross indicated mean effective pressure (IMEP) was maximized for each test by varying spark timing. Water was injected into the combustion chamber at water to fuel ratios (WFRs) of 0.38, 1.0, and 1.5 by mass. These WFRs were chosen by the sponsor; the lowest possible WFR was to be tested as well as the 1.0 and 1.5 ratios. The lowest value of 0.38 was determined by testing the mass flow rate of the water injectors at decreasing durations. It was found that at WFRs lower than 0.38 the mass of water injected varied due to the injector's response properties. The start of injection (SOI) for water was swept from 180 degrees before top dead center (℗ʻBTDC) to 40 ℗ʻBTDC on the compression stroke in 20℗ʻ increments at each load condition tested. Before water injection tests began, each load point was tested and optimized to obtain baselines to be used for comparison against the water injection results for each CR tested. For each test performed an analysis was conducted to determine the effects of water injection of net fuel conversion efficiency, coefficient of variation (COV) of IMEP, and heat release rate which are discussed in greater detail later in this paper. Fuel conversion efficiency was used to determine if the water increased or decreased the conversion from fuel energy to mechanical work and quantified how it was impacted. The stability of combustion was determined by using the IMEP coefficient of variance which is common practice in ICE analysis to see how the water effected the variance in IMEP from cycle to cycle. Lastly heat release data was used to determine if the burn rate and ignition delay was impacted with the presence of water. From this data trends were identified and conclusions drawn regarding the overall impact water injection has on combustion.

Download or read book Water Injection and Its Impact on Knock Mitigation in Spark Ignited Engines written by and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : One of the limiting factors influencing the improvement of engine efficiency in gasoline engines is engine knock. Several techniques including reduced compression ratio, cooled exhaust gas recirculation, using high premium fuels, late intake valve closing have been used to mitigate knock at different operating regimes. Water due to its higher latent heat of vaporization compared to gasoline fuel has been used to reduce the charge temperature and mitigate knock. When water is injected into the intake manifold or into the cylinder, it evaporates by exchanging energy from the surrounding mixture resulting in charge cooling. This allows the engine to be run with advanced spark timing without engine knock resulting in better engine performance. With this motive, the impact of water injection on the combustion characteristics of gasoline direct injection engine was investigated. The research was conducted in three parts. First, an analytical model was developed using the principles of thermodynamics to determine the impact of direct water injection on the cycle efficiency. An ideal thermodynamic cycle with constant volume heat addition was considered for the analysis consisting of air, fuel and water mixture. State properties of the mixture were determined at different points in the thermodynamic cycle and efficiency was calculated. This established a baseline on the amount of water that can be injected into the cylinder and its impact on the overall cycle efficiency. This was followed by spray studies on a spray and combustion vessel that were conducted at engine conditions by varying the ambient conditions to determine the vaporization of water and water methanol sprays. This study gives a comparison of the amount of water that can be vaporized from the thermodynamic model. Experimental studies were conducted on a single cylinder engine with a compression ratio of 10.9:1. Baseline tests without water injection were run using gasoline fuel blended with 10% Ethanol (E10) (Anti-Knock Index = 87.0) injected directly into the cylinder. Impact of water injection was studied by injecting water and blends of water and methanol in the intake manifold at different water fuel ratios within controlled knock limit. Furthermore, injection mechanism was changed to direct water injection and tests were conducted at the same conditions to compare the effect of water injection mechanism on the combustion and knock performance.

Download or read book End zone Water Injection as a Means of Suppressing Knock in a Spark ignition Engine written by Rinaldo J. Brun and published by . This book was released on 1944 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summary: An investigation has been made of the effectiveness of water injection into the combustion end zone of a spark-ignition engine cylinder for the suppression of knock. Pressure-time recoreds obtained show that injection of water at 60° B.T.C. on the compression stroke at a water-fuel ratio of 0.3 rendered M-3 fuel as good as S-3 fuel from an antiknock consideration. The optimum crank angle for injection of water into the end zone was found to be critical. As the injection angle was increased beyond the optimum, the quantity of water required to suppress knock increased to 3.6 water-fuel ratio at 132° B.T.C. The water quantity could not be increased beyond 3.6 water-fuel ration because of injection-pump limitations; however, a further increase in the injection angle up to the earliest angle obtainable, which was 20° A.T.C. on the intake stroke, continuously increased the knock intensity. The engine operating conditions of the tests did not simulate those encountered in flight, especially with regard to the operating speed of 570 rpm. For this reason the results should only be regarded as of theoretical importance until further investigation has been made.

Download or read book Modelling Spark Ignition Combustion written by P. A. Lakshminarayanan and published by Springer Nature. This book was released on with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multi dimensional Modeling of Mixing and Combustion of Direct Injection Spark Ignition Engines written by Li Fan and published by . This book was released on 2000 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book 1D and Multi D Modeling Techniques for IC Engine Simulation written by Angelo Onorati and published by SAE International. This book was released on 2020-04-06 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: 1D and Multi-D Modeling Techniques for IC Engine Simulation provides a description of the most significant and recent achievements in the field of 1D engine simulation models and coupled 1D-3D modeling techniques, including 0D combustion models, quasi-3D methods and some 3D model applications.

Download or read book Large eddy Simulations of Direct injection Spark ignition Engine Spray and Flow Variability written by and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cycle-to-cycle variations (CCVs) in engines limit the ability of engine designers to reach the theoretical limits of engine efficiency. This study investigates CCVs in Direct-injection Spark-ignition (DISI) engines through Large-eddy Simulations (LES). Multi-cycle simulations of motored engine flow and spray simulations with variable boundary conditions were performed. The Dynamic Structure turbulence model, which is an advanced 1-equation non-viscosity turbulence model, was used to enable coarser, engineering type meshes and reasonable computational requirements. Multi-cycle motored engine simulations were run for an optical engine at several different engine operating conditions. Comparisons included both pressure and velocity measurements using Particle Image Velocimetry (PIV). Simulations were run using computational domains that either did or did not include intake and exhaust mixing plenums. Results from runners-only and full-domain simulations were overall similar, but there were differences in specific flow structures at certain times. Changes to engine speed or manifold pressure increased flow magnitudes, even after adjusting for different mean piston speeds, but had relatively minor effects on the flow structure. A spray model adapted from diesel spray simulations is presented. The adapted models were unable to match experimental trends with changing ambient density in both liquid and vapor phases simultaneously. Two spray break-up model parameters were changed to vary as functions of ambient density, which greatly improved the vapor predictions but worsened liquid predictions. Two methods from Uncertainty Quantification (UQ) were used to test the response of the spray models to prescribed uncertainty in spray boundary conditions. The effects of having uncertainty in two numerical model parameters and two physical boundary conditions was examined. Overall simulation uncertainty was much larger than the experimental uncertainty. Further tests showed the uncertainty in the simulation response variables was due primarily to uncertainty in the numerical modeling parameters. When examining the effects of uncertainty in the physical boundary conditions alone, the resulting variability in the response variables was approximately equal to the variability in the spray measurements.

Download or read book Modeling and Simulation of Spark Ignition in Turbocharged Direct Injection Spark Ignition Engines written by Lukas Schäfer and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling of Real Fuels and Knock Occurrence for an Effective 3D CFD Virtual Engine Development written by Francesco Cupo and published by Springer Nature. This book was released on 2020-09-14 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: To drastically reduce the emission of greenhouse gases, the development of future internal combustion engines will be strictly linked to the development of CO2 neutral fuels (e.g. biofuels and e-fuels). This evolution implies an increase in development complexity, which needs the support of engine 3D-CFD simulations. Francesco Cupo presents approaches to accurately describe fuel characteristics and knock occurrence in SI engines, thus improving the current simulation capability in investigating alternative fuels and innovative combustion processes. The developed models are successfully used to investigate the influence of ethanol-based fuels and water injection strategies on knock occurrence and to conduct a virtual fuel design for and engine operating with the innovative SACI combustion strategy.

Download or read book The Water Injection of a One Cylinder Spark Ignition Engine by Two Different Methods written by Harvey Parnell Metzler and published by . This book was released on 1967 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Large eddy Spray Simulation Under Direct injection Spark ignition Engine like Conditions written by Hongjiang Li and published by . This book was released on 2019 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of this dissertation is on the development and improvement of spray models for large-eddy simulation (LES) of turbulent two-phase flows in direct-injection spark-ignition (DISI) engines. The work can be regarded as a continuation of the development of LES framework at the Engine Research Center (ERC). The LES two-phase governing equations are solved using the Lagrangian-Eulerian (LE) approach in a variation of the OpenFOAM-2.3.x code developed by the OpenFOAM Foundation. A mixed-type one-equation dynamic structure turbulence model is used as the basis for turbulence modeling. LES models are developed for DISI spray breakup, Sub-grid scale (SGS) turbulent dispersion, and SGS energy dissipation rate. The spray breakup model builds on top of the hybrid Kelvin-Helmholtz (KH)/Rayleigh-Taylor (RT) model by incorporating the bag/bag-stamen breakup regimes. A concept of RT breakup length is introduced to account for the plume-interactions and the effective nozzle diameter of DISI spray. The SGS models are developed in the context of LES and require the SGS kinetic energy, which is obtained by solving its transport equation in the turbulence model. The performance of the new models is evaluated against a wide range of DISI spray experiments covering both early and late injection engine-like conditions. Examination of spray characteristics is performed for both global and local quantities such as penetration length, Sauter mean diameter (SMD), droplet velocity, liquid-phase concentrations, and spray envelop. The discussion focuses primarily on the DISI spray breakup, followed by \textit{a posteriori} test results of the SGS models. An uncertainty quantification (UQ) study is also performed to analyze the impact of spray boundary conditions and breakup model parameters on LES of DISI sprays. LES results show that the addition of models for bag/bag-stamen breakup regimes results in more accurate predictions of spray characteristics. The modified breakup length concept also predicts more realistic penetration curves across a range of ambient temperature and density conditions without tuning the model parameters. The improved SGS dispersion model correctly predicts local liquid-phase characteristics such as velocity and projected liquid volume fraction. A preliminary study of SGS dissipation rate modeling also shows that the SGS model is able to accurately predict the energy balance between the resolved and the SGS fields across various mesh resolutions.

Download or read book Direct Injection of Water in Spark Ignition Engines written by Arthur Wiley Downs and published by . This book was released on 1949 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book THE IMPACT OF WATER INJECTION ON SPARK IGNITION ENGINE PERFORMANCE UNDER HIGH LOAD OPERATION written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : An experimental effort has been completed in which water injection was investigated as a means of enabling increases in engine output and high load efficiency. Water was injected into the intake port of a direct fuel injected, 4-cylinder, boosted engine with dual independent variable valve timing. The water was shown to increase volumetric efficiency and decrease the onset of knock which in turn enable more optimal combustion phasing. Both of these affects resulted increases in load of up to 5.5% at the same manifold pressure as the baseline case. The advancement of combustion phasing, combined with elimination of fuel enrichment resulted in an increase in full load thermal efficiency of up to 35%. Analysis is provided around these affects, as well as the phase transformation of water throughout the engine cycle.

Download or read book Simulation of Spray Combustion in a Direct injected Spark ignited Two stroke Engine written by Himanshu Rai and published by . This book was released on 1995 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Modeling of Gasoline Direct Injection Spark Ignition Engines During Cold start written by Arun Cherumuttathu Ravindran and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Developing a profound understanding of the combustion characteristics of the cold-start phase of a Direct Injection Spark Ignition (DISI) engine is critical to meeting the increasingly stringent emissions regulations. Computational Fluid Dynamics (CFD) modeling of gasoline DISI combustion under normal operating conditions has been discussed in detail using both the detailed chemistry approach and flamelet models (e.g., the G-Equation). However, there has been little discussion regarding the capability of the existing models to capture DISI combustion under cold-start conditions. Accurate predictions of cold-start behavior involves the efficient use of multiple models - spray modeling to capture the split injection strategies, models to capture the wall-film interactions, ignition modeling to capture the effects of retarded spark timings, combustion modeling to accurately capture the flame front propagation, and turbulence modeling to capture the effects of decaying turbulent kinetic energy. The retarded spark timing helps to generate high heat flux in the exhaust for a rapid catalyst light-off of the after-treatment system during cold-start. However, the adverse effect is a reduced turbulent flame speed due to decaying turbulent kinetic energy. Accordingly, developing an understanding of the turbulence-chemistry interactions is imperative for accurate modeling of combustion under cold-start conditions.This study introduces a modified version of the G-Equation combustion model called the GLR model (G-Equation for Lower Reynolds number regimes) that exhibits improved performance under cold-start conditions. The model attempts to estimate the turbulent flame speed based on the local conditions of fuel concentration and turbulence intensity. The local conditions and the associated turbulent-chemistry interactions are studied by tracking the flame front on the Borghi-Peters regime diagram. To accurately model the DISI combustion process, it is important to account for the effects of the spark energy discharge process. In this work, an ignition model is presented that is compatible with the G-Equation combustion model, and which accounts for the effects of plasma expansion and local mixture properties such as turbulence and the equivalence ratio on the early flame kernel growth. The model is referred to as the Plasma Velocity on G-Surface (PVG) model, and it uses the G-surface to capture the kernel growth. The model derives its theory from the DPIK model and applies its concepts onto an Eulerian framework, thereby removing the need for Lagrangian particles to track the kernel growth. Finally, a methodology of using machine learning (ML) techniques in combination with 3D CFD modeling to optimize the cold-start fast-idle phase of a DISI engine is presented. The optimization process implies the identification of the range of operating parameters, that will ensure the following criteria under cold-start conditions: (1) a fixed IMEP of 2 bar (BMEP of 0 bar), (2) a stoichiometric exhaust equivalence ratio (based on carbon-to-oxygen atoms) to ensure the efficient operation of the after-treatment system, (3) enough exhaust heat flux to ensure a rapid light-off of the after-treatment system, and (4) acceptable NOx and HC emissions. Gaussian Process Regression (GPR)-based ML models are employed to make predictions about DISI cold-start behavior with acceptable accuracy and a substantially reduced computational time.

Download or read book Water injection in a spark ignition engine written by Isham George Kennon and published by . This book was released on 1949 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: