Download or read book Numerical Modeling of Fuel Injection Into an Accelerating Turning Flow with a Cavity written by Ben James Colcord and published by . This book was released on 2011 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: Deliberate continuation of the combustion in the turbine passages of a gas turbine engine has the potential to increase the efficiency and the specific thrust or power of current gas-turbine engines. This concept, known as a turbine-burner, must overcome many challenges before becoming a viable product. One major challenge is the injection, mixing, ignition, and burning of fuel within a short residence time in a turbine passage characterized by large three-dimensional accelerations. One method of increasing the residence time is to inject the fuel into a cavity adjacent to the turbine passage, creating a low-speed zone for mixing and combustion. This situation is simulated numerically, with the turbine passage modeled as a turning, converging channel flow of high-temperature, vitiated air adjacent to a cavity. Both two- and three-dimensional, reacting and non-reacting calculations are performed, examining the effects of channel curvature and convergence, fuel and additional air injection configurations, and inlet conditions. Two-dimensional, non-reacting calculations show that higher aspect ratio cavities improve the fluid interaction between the channel flow and the cavity, and that the cavity dimensions are important for enhancing the mixing. Two-dimensional, reacting calculations show that converging channels improve the combustion efficiency. Channel curvature can be either beneficial or detrimental to combustion efficiency, depending on the location of the cavity and the fuel and air injection configuration. Three-dimensional, reacting calculations show that injecting fuel and air so as to disrupt the natural motion of the cavity stimulates three-dimensional instability and improves the combustion efficiency.

Download or read book Simulation and Numerical Modelling of Three phase Flow in Automotive High pressure Fuel Injectors written by Eduardo Gomez Santos and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of Injection Processes in an Innovative 3D CFD Tool for the Simulation of Internal Combustion Engines written by Marlene Wentsch and published by Springer. This book was released on 2018-05-16 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to the large number of influencing parameters and interactions, the fuel injection and therewith fuel propagation and distribution are among the most complex processes in an internal combustion engine. For this reason, injection is usually the subject to highly detailed numerical modeling, which leads to unacceptably high computing times in the 3D-CFD simulation of a full engine domain. Marlene Wentsch presents a critical analysis, optimization and extension of injection modeling in an innovative, fast response 3D-CFD tool that is exclusively dedicated to the virtual development of internal combustion engines. About the Author Marlene Wentsch works as research associate in the field of 3D-CFD simulations of injection processes at the Institute of Internal Combustion Engines and Automotive Engineering (IVK), University of Stuttgart, Germany.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Simulation of High Speed Cavity Flows in a Scramjet Engine by the Space Time CESE Method written by and published by . This book was released on 2005 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this report we summarize numerical results of supersonic flows over open cavities in the setting of a dual-mode ramjet/scramjet engine. To calculate the unsteady cavity flows, we employ the Space-Time Conservation Element and Solution Element (CESE) method, a novel numerical method based on a unified treatment of space and time in calculating flux balance. Supersonic cavity flows with and without fuel injection are studied to understand the mechanisms of mixing enhancement and flame holding by cavities. Without injection, numerical results compared favorably with the experimental data for dominant frequencies and time-averaged pressure coefficients inside the cavities. With an upstream injection, the flow oscillations are drastically suppressed. In a downstream injection arrangement, cavity-generated acoustic waves and vortices greatly enhance fuel/air mixing. Numerical results show that the CESE method provides high-fidelity numerical results of unsteady flows in the advanced scramjet engine concept.

Download or read book Numerical Modelling of Multiphase Flow at the Outlet of a High pressure Fuel Injector for Gasoline Direct Injection written by Andrew Gerges and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings written by and published by . This book was released on 1971 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of an Integrated CFD Approach for Internal Nozzle Flows and Sprays written by and published by . This book was released on 2013 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: In modern automotive internal combustion engines the atomization and spraying processes of liquid fuel is an important mechanism by which the fuel is mixed effectively with the combustion chamber gas. The homogeneity of the fuel-air mixture charge and the timing to achieve it affect the characteristics of the subsequent combustion in a number of ways. Experimentalists have found that the atomization process is influenced by the fuel delivery system, specifically, the operating conditions of fuel injection and the internal geometry of the injector nozzles. Therefore, modeling researchers must develop spray models that properly take into account these effects from the injectors. A Computational Fluid Dynamics (CFD) model is developed to simulate internal injector nozzle flows and the external-nozzle atomization and sprays in an integrated way. In light of the continuous nature of the flow within and near the nozzle, an Eulerian flow solver is developed and applied in these regions. This flow solver models compressible two-phase flows with general conservation laws of fluid dynamics. Differences in the thermodynamic states of liquid and gas phases are properly modeled with an Equation of State (EOS). The chosen numerical methods are sufficiently robust to handle pressure and density gradients up to 1000:1 and are able to cover the typical operating ranges of modern diesel and gasoline injection systems. A phase equilibrium model is developed based on the fundamental thermodynamic laws. It is implemented into the Eulerian flow solver to predict phase change in the flows - in particular, the cavitation of liquid fuel within the fuel injector nozzle and how it influences the external flows. A number of test problems are simulated to verify the numerical methods and validate the proposed models. These include two-phase shock tube problems, a shock-interface interaction problem, a converging-diverging nozzle flow problem, and most importantly, high-pressure fuel injection problems. The Eulerian flow solver requires the CFD mesh size to be smaller than the characteristic phase interface length scale in order to apply the continuum fluid assumption. This requirement is challenged beyond a certain distance from the nozzle where the spray is dispersed. Here the mesh size affordable by engineering calculation is too coarse for the Eulerian solver to be applied. At this stage, the Eulerian liquid phase can be transitioned into Lagrangian discrete particles to model the dispersed spray droplets. The modeling of the sub-grid droplet size at this transition stage is based on local balances between turbulent kinetic energy and surface energy. The Eulerian flow solver coupled with the phase equilibrium model and the Eulerian-Lagrangian transition model provides an engineering CFD approach to study the effects of injector nozzle flows on the atomization and sprays.

Download or read book Cfd Modeling of Turbulent Flows Around the Ssme Main Injector Assembly Using Porosity Formulation written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-06 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hot gas turbulent flow distribution around the main injector assembly of the Space Shuttle Main Engine (SSME) and LOX flow distribution through the LOX posts have a great effect on the combustion phenomena inside the main combustion chamber. In order to design a CFD model to be an effective engineering analysis tool with good computational turn-around time (especially for 3-D flow problems) and still maintain good accuracy in describing the flow features, the concept of porosity was employed to describe the effects of blockage and drag force due to the presence of the LOX posts in the turbulent flow field around the main injector assembly of the SSME. Two-dimensional numerical studies were conducted to identify the drag coefficients of the flows, both through tube banks and round the shielded posts, over a wide range of Reynolds numbers. Empirical, analytical expressions of the drag coefficients as a function of local flow Reynolds number were then deduced. The porosity model was applied to the turbulent flow around the main injector assembly of the SSME, and analyses were performed. The 3-D CFD analysis was divided into three parts: LOX dome, hot gas injector assembly, and hydrogen cavity. The numerical results indicate that the mixture ratio at the downstream of injector face was close to stoichiometric around baffle elements. Cheng, Gary C. and Chen, Y. S. and Farmer, Richard C. Unspecified Center...

Download or read book Numerical Modelling of Fuel Injection and Stratified Turbulent Combustion in a Direct injection Spark ignition Engine Using an Open Source Code written by and published by . This book was released on 2014 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scramjet Combustion written by Gautam Choubey and published by Butterworth-Heinemann. This book was released on 2022-07-08 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scramjet Combustion explores the development of a high-speed scramjet engine operating in the supersonic/hypersonic range for various air and space transport applications. The book explains the basic structure, components, working cycle, and the relevant governing equations in a clear manner that speaks to both advanced and more novice audiences. Particular attention is paid to efficient air–fuel combustion, looking at both the underlying fundamentals of combustion as well strategies for obtaining optimum combustion efficiency. Methods for reaching the chemically correct air–fuel ratio, subsequent flame, and combustion stabilization as air enters at supersonic speed are also outlined. Further, it includes the continuous on-going efforts, innovations, and advances with respect to the design modification of scramjet combustors, as well as different strategies of fuel injections for obtaining augmented performance while highlighting the current and future challenges. - Outlines the fundamentals of scramjet engines including their basic structure and components, working cycle, governing equations, and combustion fundamentals affecting the combustion and mixing processes - Presents new design modifications of scramjet combustors and different fuel injection strategies including combined fuel injection approaches - Discusses core topics such as chemical kinetics in supersonic flow, fuel–air mixing methods, strategies for combating combustion difficulties, and subsequent flame and combustion stabilization that can be applied to scramjets - Describes the pedagogy for computational approaches in simulating supersonic flows

Download or read book A Numerical Model for Elastohydrodynamic Analysis of Plunger and Barrel Clearances in Fuel Injection Equipment written by D. H. Gibson and published by . This book was released on 1990 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling of the Internal Two Phase Flow in a Gas Centered Swirl Coaxial Fuel Injector written by and published by . This book was released on 2009 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Predicting the liquid film dynamics inside the injector cup of gas-centered swirl coaxial fuel injectors requires a general two-phase approach that is appropriate for all liquid volume fractions, high Weber number, and complex geometries. The rapid exchange of momentum at the highly convoluted interface requires tight numerical coupling between the gas and liquid phases. An Eulerian two-phase model is implemented to represent the liquid and gas interactions in the injector as well as the atomization processes at the rough interface. The model, originally proposed by Vallet et al, assumes that in the limit of infinite Reynolds and Weber number, features of the atomization process acting at large length scales are separable from small scale mechanisms. A transport equation for the liquid volume fraction represents the dispersion of the liquid into the gas via a traditional turbulent diffusion hypothesis. A model for the growth of mean interfacial surface area is then used to characterize the growth of instability at the interface, allowing a characterization of Sauter mean diameter. The model shows promise as a computationally inexpensive tool for characterizing spray quality in regions where optical experimental data are difficult to obtain and two-phase direct numerical simulation methods are too demanding.

Download or read book Numerical Simulation of Reactive Flow Associated with a Lobed Fuel Injector written by Thomas Selerland and published by . This book was released on 1997 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 1016 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Conference Papers Index written by and published by . This book was released on 1987 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: Monthly. Papers presented at recent meeting held all over the world by scientific, technical, engineering and medical groups. Sources are meeting programs and abstract publications, as well as questionnaires. Arranged under 17 subject sections, 7 of direct interest to the life scientist. Full programs of meetings listed under sections. Entry gives citation number, paper title, name, mailing address, and any ordering number assigned. Quarterly and annual indexes to subjects, authors, and programs (not available in monthly issues).