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Swirl Coaxial Injector Development Part Ii Cfd Modeling
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Book Synopsis Swirl Coaxial Injector Development, Part II: CFD Modeling by :
Download or read book Swirl Coaxial Injector Development, Part II: CFD Modeling written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Injector design is critical to obtaining the dual goals of long engine life as well as providing high energy release efficiency in the main combustion chamber. Introducing a swirl component in the injector flow can enhance the propellant mixing and thus improve engine performance. A combined experimental and computational effort is underway to examine the properties of GOX-centered, swirl coaxial injectors to examine their performance and lifetime characteristics. These injectors can be easily manufactured and can be designed to maintain a low face temperature, which will improve engine life. Therefore, swirl coaxial injectors, which swirl liquid fuel around a gaseous oxygen core, show promise for the next generation of high performance staged combustion rocket engines utilizing hydrocarbon fuels. The purpose of this work is to not only examine the properties of these injectors, but also to develop a design methodology, utilizing a combination of high-pressure cold-flow testing, uni-element hot- fire testing, and computations to create a high performing, long life swirl coaxial injector for multi-element combustor use.
Book Synopsis Swirl Coaxial Injector Development, Part I: Test Results by :
Download or read book Swirl Coaxial Injector Development, Part I: Test Results written by and published by . This book was released on 2002 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sierra Engineering, in conjunction with the Air Force Research Laboratory Propulsion Directorate, has undertaken a program to develop a gas-centered, swirl coaxial injector. This injector design will be used in the multi-element Advanced Fuels Tester (AFT) engine to test a variety of hydrocarbon propellants. As part of this program, a design methodology is being developed which will be applicable to future injector design efforts. The methodology combines cold flow data, acquired in the AFRL High Pressure Injector Flow facility, uni-element hot fire data, collected in AFRL Test Cell EC-1, and a computational effort conducted at University of Alabama-Birmingham, to identify key design features and sensitivities. Results from the computational effort will be presented in the Part II companion paper (9). Three different gas-centered swirl coaxial element concepts were studied: a converging design, a diverging design, and a pre-filming design. The cold flow experiments demonstrated that all three classes of elements produced an extremely dense, solid cone spray, with the highest mass density in the center. The atomization of all of these injectors was excellent, producing mean drop sizes 1/3 to 1/4 of that typically measured for shear coaxial elements operating under similar conditions. Uni-element hot fire testing of these elements has begun, but the elements have not yet been tested at the design operating conditions. Preliminary low chamber pressure test results show the converging design performs better than the pre-filming and diverging design. Uni-element C* efficiencies in excess of 90% have been measured over a wide-range of mixture ratios.
Book Synopsis Development of GOX/Hydrocarbon Multi-Element Swirl Coaxial Injector Technology by :
Download or read book Development of GOX/Hydrocarbon Multi-Element Swirl Coaxial Injector Technology written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In developing the advanced liquid rocket engine, injector design is critical to obtaining the dual goals of long engine life as well as providing high-energy release efficiency in the main combustion chamber. Introducing a swirl component in the injector flow can enhance the propellant mixing and thus improve engine performance. Therefore, swirl coaxial injectors, which swirl liquid fuel around a gaseous oxygen core, show promise for the next generation of high performance staged combustion rocket engines utilizing hydrocarbon fuels. Understanding the mixing and combustion characteristics of the swirl coaxial flow provides the insight of optimizing the injector design. A joint effort of Sierra Engineering (Sierra) and the Propulsion Directorate of the Air Force Research Lab (AFRL) was conducted to develop a design methodology, utilizing both high-pressure cold-flow testing and uni-element hot-fire testing, to create a high performing, long life swirl coaxial injector for multi-element combustor use. Several swirl coax injector configurations designed and fabricated by Sierra have been tested at AFRL. The cold-flow tests and numerical simulations have been conducted. The cold flow result provided valuable information of flow characteristics of swirl coaxial injectors. However, there are two important flow features of liquid rocket engines missed from the cold flow test: (1) the effect of combustion on the propellant mixing, and (2) the interaction of multiple injectors. The present work studies the hot flow environment specifically the multiple element swirl coaxial injector. Numerical simulations were performed with a pressure-based computational fluid dynamics (CFD) code, FDNS. CFD results produced loading environments for an ANSYS finite element thermal/structural model. Since the fuels are injected at temperature below its critical temperature, the effect of phase change and chemical reactions needs to be accounted for in the CFD model.
Book Synopsis Swirl Coaxial Injector Development by :
Download or read book Swirl Coaxial Injector Development written by and published by . This book was released on 2002 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sierra Engineering and the Air Force Research Laboratory Propulsion Directorate, have undertaken a program to develop gas-centered, swirl coaxial injectors. This injector design will be used in the multi-element Advanced Fuels Tester (AFT) engine to test a variety of hydrocarbon propellants. As part of this program, a design methodology is being developed which will be applicable to future injector design efforts. The methodology combines cold flow data, acquired in the AFRL High Pressure Injector Flow facility, uni-element hot fire data, collected in AFRL Test Cell EC-1, and a computational effort conducted at University of Alabama-Birmingham, to identify key design features and sensitivities. Only results from the experimental effort will be presented in this work. Three different gas-centered swirl coaxial element concepts are being studied: a converging design, a diverging design, and a pre-filming design. The cold flow experiments demonstrated that all three classes of elements produced an extremely dense, solid cone spray, with the highest mass density in the center. The atomization of all of these injectors was excellent, producing mean drop sizes 1/3 to 1/4 of that typically measured for shear coaxial elements operating under similar conditions. Uni-element hot fire testing has found that the converging designs produce C* efficiencies in excess of 90% over a wide-range of mixture ratios and pressure conditions. Near the design pressure, efficiencies exceeding 96% have been measured. In the diverging designs, a chamber oscillation of near 200 Hz has been noted. The cause of this oscillation is under investigation.
Book Synopsis Development of GOX/Kerosene Swirl-Coaxial Injector Technology by :
Download or read book Development of GOX/Kerosene Swirl-Coaxial Injector Technology written by and published by . This book was released on 2003 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: In developing an advanced liquid rocket engine, injector design is critical to obtaining the dual goals of long engine life and high-energy release efficiency in the main combustion chamber. A joint effort of Sierra Engineering (Sierra) and the Propulsion Directorate of the Air Force Research Lab (AFRL) was conducted to develop a design methodology, utilizing both high- pressure cold-flow testing and uni-element hot fire testing, to create a high performing, swirl coaxial injector for multi-element combustor use. The results of this joint effort have been documented in a series of JANNAF and AIAA meeting papers. The present work studies the hot flow environment specifically the multiple element swirl coaxial injector Numerical simulations were performed with a multiple-phase, pressure-based computational fluid dynamics (CFD) code, FDNS. CFD results produced loading environments for an ANSYS finite element thermal/structural model. Since the fuels are injected at a temperature below its critical temperature, the effect of phase change and chemical reactions needs to be accounted for in the CED model. A homogeneous spray approach with a real-fluid property model was employed in the FDNS code to simulate the spray combustion phenomena over a wide range of operating conditions. Future work, which will not be presented in this paper, will compare these numerical results to planned hot fire test results.
Book Synopsis 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit July 20-23, 2003, Huntsville, Alabama: 03-4750 by :
Download or read book 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit July 20-23, 2003, Huntsville, Alabama: 03-4750 written by and published by . This book was released on 2003 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis 41st AIAA Aerospace Sciences Meeting & Exhibit by :
Download or read book 41st AIAA Aerospace Sciences Meeting & Exhibit written by and published by . This book was released on 2003 with total page 566 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Analysis of Injection Processes in an Innovative 3D-CFD Tool for the Simulation of Internal Combustion Engines by : Marlene Wentsch
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.
Book Synopsis 41st AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit 10-13 July 2005, Tucson, Arizona: 05-4100 - 05-4149 by :
Download or read book 41st AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit 10-13 July 2005, Tucson, Arizona: 05-4100 - 05-4149 written by and published by . This book was released on 2005 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit July 20-23, 2003, Huntsville, Alabama: 03-4550 - 03-4599 by :
Download or read book 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit July 20-23, 2003, Huntsville, Alabama: 03-4550 - 03-4599 written by and published by . This book was released on 2003 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Modeling of the Internal Two-Phase Flow in a Gas-Centered Swirl Coaxial Fuel Injector by :
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.
Book Synopsis The Development of a Methodology to Scale Between Cold-Flow and Hot-Fire Evaluations of Gas-Centered Swirl Coaxial Injectors by :
Download or read book The Development of a Methodology to Scale Between Cold-Flow and Hot-Fire Evaluations of Gas-Centered Swirl Coaxial Injectors written by and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Uni-element cold flow and hot fire evaluations were performed on a variety of gas-centered swirl coaxial injectors. Gaseous oxygen and various liquid hydrocarbons were used in the combustion evaluations, while water and gaseous nitrogen were the simulants for the cold flow experiments. The connections between the two sets of data were examined. The cold flow experiments demonstrated that the mixing efficiency of the various injector designs was highly sensitive to the internal geometry of the injector as well as the scaling methodology used to simulate the hot-fire conditions. When the proper scaling methodology was employed, a correlation which captures the general trend of injector geometry and c ̂performance between the measured cold-flow mixing efficiency and hot-fire c ̂performance was observed. This semi-empirical correlation was developed based on a film stripping mechanism that relates the measured c ̂efficiency of these injectors to the injector geometry and fuel properties. The effects of injector geometry on the injector internal flowfield were ascertained with a combination of cold-flow CFD simulations and experimental measurements. The correlation also implies that fuel properties are secondary to injector geometry effects in determining the performance of various injector configurations. Hot-fire testing of several common hydrocarbon fuels including RP-1, Butane, JP-10, JP-7 and JP-8 confirmed that injector geometric effects dominated performance and demonstrated that c ̂efficiency in excess of 95% is achievable with all of these fuels. However, the effect of fuel properties does appear to be within the measurement limits of the experiments and a correlating parameter which captures these effects was found.
Book Synopsis Coaxial Injector Development Test Series 1.2-09-NNJ. by :
Download or read book Coaxial Injector Development Test Series 1.2-09-NNJ. written by and published by . This book was released on 1967 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Development of CFD Model for Simulating Gas/liquid Injectors in Rocket Engine Design by : G. C. Cheng
Download or read book Development of CFD Model for Simulating Gas/liquid Injectors in Rocket Engine Design written by G. C. Cheng and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis CFD Simulation of Liquid Rocket Engine Injectors. Part 2. Simulations of the RCM-2 Experiment by : Richard Farmer
Download or read book CFD Simulation of Liquid Rocket Engine Injectors. Part 2. Simulations of the RCM-2 Experiment written by Richard Farmer and published by . This book was released on 2001 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The sub-critical combustion case, RCM-2, was simulated with both heterogeneous and homogeneous spray combustion models. The MASCOTTE test data should be better than any which have been previously used to tune the several parameters in these models. It is unreasonable to expect that spray flames, even of hydrogen and oxygen, can be accurately predicted without extensive model validation with test data representative of the conditions which exists in rocket engine combustion chambers. Even global data such as chamber pressure and thrust have not been obtained for single coaxial element combustor flows. The IWRCM data provide a good starting point, but no CFD model tuning has yet been attempted for such experiments. Direct comparisons of predictions to test data at this point will not establish which of several modeling techniques is best.
Book Synopsis Scientific and Technical Aerospace Reports by :
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1989 with total page 1148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Development of an Integrated CFD Approach for Internal Nozzle Flows and Sprays by :
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 0 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.
