› › Calibration And Injection Rate Shaping Approaches Using 1d Hydraulic Diesel Injector Modeling For Gasoline Compression Ignition Applications

CALIBRATION AND INJECTION RATE SHAPING APPROACHES USING 1D HYDRAULIC DIESEL INJECTOR MODELING FOR GASOLINE COMPRESSION IGNITION APPLICATIONS

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Page : pages

File Size : 17,8 MB

Release : 2022

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Abstract : The gasoline compression ignition (GCI) works on the principle of harnessing the benefits of light distillates in a compression ignition (CI) engine. Recent research has shown that along with air management and after-treatment systems; fuel systems also play a vital role in enabling GCI technology. The injector in the fuel injection system (FIS) is a key component driving the efficiency of the combustion phenomena. Subsequently, injection strategies, characteristics, and overall injection quality influence the combustion process and controls certain metrics like fuel consumption, pollutant emissions, and combustion noise. In this work, a one-dimensional (1-D) model of a heavy-duty diesel injector employed in Cummins ISX15 Engine, built in a commercially available computer software called Gamma Technologies (GT)-SUITE, was studied, and analyzed. This work focuses on developing a generalized methodology from previous work to adapt this injector with gasoline-like fuels by recalibrating the discharge coefficients using in-built GT-SUITE optimization techniques. Post recalibration, the 1-D model closely reproduces experimentally measured injection performance characteristics like rate of injection (ROI) profiles, injected quantities, hydraulic delays, and needle lift profiles for the heavy-duty, high-pressure diesel injector using gasoline-like fuels across engine operating points of interest, thereby enabling GCI. As the previous study has demonstrated the potential of injection rate shaping in the mitigation of oxides of nitrogen (NOx) emissions, this validated 1-D model was further used to investigate various injector geometries to produce custom injection rate shapes. Finally, an optimization methodology was developed to generate rate shape of interest to obtain a single set of the selected dimensional parameters across high-efficiency engine operating points using the in-built GT-SUITE optimization techniques. Furthermore, a full factorial design of experiments (DoE) using the candidate injector geometries, hydraulic components were simulated and post-processed to obtain an optimal rate shape, thereby acting as a validation tool for the optimal rate shape obtained using GT-Suite's optimization methods.



Fuel Spray Modeling for Compression Ignition Engine Configurations

Author : Krishna Latha Ankem

Publisher :

Page : 144 pages

File Size : 19,58 MB

Release : 2005

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ISBN :

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The combination of superior fuel economy and durability has made compression ignition direct injection diesel engines popular worldwide. However, these engines can emit large amounts of ozone-forming pollutants and particulates and so are being subjected to increasingly stringent regulations that require continual improvements in the combustion process. Further, improved engine power density is necessary at high load conditions, before the CIDI engine can be considered a contender in the next generation automotive engine technology. Understanding the physics and chemistry involved in diesel combustion, with its transient effects and the inhomogeneity of spray combustion is quite challenging. Great insight into the physics of the problem can be obtained when an in-cylinder computational analysis is used in conjunction with either an experimental program or through published experimental data. The main area to be investigated to obtain good combustion begins by defining the fuel injection process and the mean diameter of the fuel particle, injection pressure, drag coefficient, rate shaping, etc., correctly. This work presents a methodology to perform the task set out in the previous paragraph and uses experimental data obtained from available literature to construct a numerical model. A modified version of a multidimensional computer code called KIVA3V was used for the computations, with improved sub-models for mean droplet diameter, injection pressure and drop distortion and drag. The results achieved show good agreement with the published experimental data. It has been of special importance to model the spray distribution accurately, as the combustion process and the resulting pollutant emission formation is intimately tied to the in-cylinder fuel distribution. The present scheme has achieved excellent results in these aspects and will make an important contribution to the numerical simulation of the combustion process and pollutant emission formation in compression ignition direct injection engines.











Modeling of End-Gas Autoignition for Knock Prediction in Gasoline Engines

Author : Andreas Manz

Publisher : Logos Verlag Berlin GmbH

Page : 263 pages

File Size : 50,28 MB

Release : 2016-08-18

Category : Science

ISBN : 3832542817

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Downsizing of modern gasoline engines with direct injection is a key concept for achieving future CO22 emission targets. However, high power densities and optimum efficiency are limited by an uncontrolled autoignition of the unburned air-fuel mixture, the so-called spark knock phenomena. By a combination of three-dimensional Computational Fluid Dynamics (3D-CFD) and experiments incorporating optical diagnostics, this work presents an integral approach for predicting combustion and autoignition in Spark Ignition (SI) engines. The turbulent premixed combustion and flame front propagation in 3D-CFD is modeled with the G-equation combustion model, i.e. a laminar flamelet approach, in combination with the level set method. Autoignition in the unburned gas zone is modeled with the Shell model based on reduced chemical reactions using optimized reaction rate coefficients for different octane numbers (ON) as well as engine relevant pressures, temperatures and EGR rates. The basic functionality and sensitivities of improved sub-models, e.g. laminar flame speed, are proven in simplified test cases followed by adequate engine test cases. It is shown that the G-equation combustion model performs well even on unstructured grids with polyhedral cells and coarse grid resolution. The validation of the knock model with respect to temporal and spatial knock onset is done with fiber optical spark plug measurements and statistical evaluation of individual knocking cycles with a frequency based pressure analysis. The results show a good correlation with the Shell autoignition relevant species in the simulation. The combined model approach with G-equation and Shell autoignition in an active formulation enables a realistic representation of thin flame fronts and hence the thermodynamic conditions prior to knocking by taking into account the ignition chemistry in unburned gas, temperature fluctuations and self-acceleration effects due to pre-reactions. By the modeling approach and simulation methodology presented in this work the overall predictive capability for the virtual development of future knockproof SI engines is improved.





Direct Injection Systems

Author : Cornel C Stan

Publisher : SAE International

Page : 126 pages

File Size : 25,51 MB

Release : 2002-11-05

Category : Technology & Engineering

ISBN : 0768030498

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Book Description

Direct Injection Systems: The Next Decade in Engine Technology explores potentials that have been recognized and successfully applied, including fuel direct injection, fully variable valve control, downsizing, operation within hybrid scenarios, and use of alternative fuels.



Low-Pressure Gasoline Fuel Injector

Author : Gasoline Fuel Injection Standards Committee

Publisher :

Page : 0 pages

File Size : 16,15 MB

Release : 2023

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This SAE Recommended Practice promotes uniformity in the evaluation tests and performance measurements that are conducted on fuel injectors used in low-pressure gasoline engine applications. The scope of this document is limited to electronically actuated fuel injection devices that are utilized in automotive gasoline port fuel injection systems where the fuel supply pressure is normally less than 1000 kPa. Detailed test procedures are provided for determining numerous PFI injector parameters, including, but not limited to, flow curves, leakage, electromechanical performance, fluid compatibility and corrosion susceptibility, durability, the effects of vibration and torsional deflection, thermal cycling effects, and noise. The standardized measurement procedures in this document are all bench tests. Characterization of the fuel spray from a low-pressure gasoline port fuel injector is quite important; however, these spray characterization tests are not addressed in this document, but are covered in a companion publication: SAE J2715.Tests and references to types of low-pressure gasoline injectors that are no longer commonly used in modern production are not included in the main body of this document. Superseded systems such as throttle body injection (TBI), central port injection (CPI), pressure-drop ratio (PDR), bottom-feed injectors, and eight-ring patternation are examples of this older technology. Those fuel system components and diagnostic tests were extensively utilized in prior decades, but find little application in the industry today. The historical detailed measurement procedures that applied to the tests on these types of injectors have been removed from the main sections of the updated SAE J1832; however, the associated overall descriptions of these hardware items that were in previous versions of SAE J1832 have been retained in the appendix for archival purposes. This SAE Recommended Practice will permit the automotive industry to evaluate, characterize, and compare the fuel injector hardware for port fuel injection systems. The use of standardized testing and evaluation procedures for fuel injectors is important to the worldwide automotive community. Standardized test procedures provide both injector manufacturers and end-users with a uniform testing procedure for each of the key injector performance parameters, instead of a specialized test protocol for each of many customers and applications. The use of these procedures for test configurations, testing methods, data reduction, and reporting that are contained in this SAE Recommended Practice will significantly enhance the ability of one test laboratory to accurately repeat and verify the results of another.