Download or read book Development of Improved CFD Tools for the Optimization of a Scramjet Engine written by Francis A. Centlivre and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the present work, a plugin has been developed for use with the DoD HPCMP CREATE-AV Kestrel multi-physics solver that adds volumetric source terms to the energy equation. These source terms model the heat released due to combustion, but are much more computationally efficient than a full chemistry model. A thrust-based optimization study was then carried out under the control of Sandia National Laboratories' Dakota toolkit. Dakota was allowed to control the amount of heat added to three regions of the scramjet combustor. The plugin was then extended to consider ignition delay time. By comparing ignition delay time to dwell time, it is possible to determine whether the fuel in a cell should be combusted. Results from this analysis are compared to results gathered using a 22-species chemistry model. The ignition delay source term is shown to capture relevant flow physics at a reduced computational cost. Additionally, the expression for second-law (exergetic) efficiency for a scramjet engine is derived and optimized using Dakota. Finally, Dakota was extended to control the geometry of the scramjet engine, allowing for the numerical optimization of the scramjet expansion system. The results from these computationally-efficient optimizations can then be used to inform researchers of potentially optimal solutions before higher-fidelity models are used.

Download or read book Coupling Computational Fluid Dynamics Analysis and Optimization Techniques for Scramjet Engine Design written by Nathan T. McGillivray and published by . This book was released on 2018 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: Various aspects of hypersonic vehicles are being rapidly explored for improved functionality. One of the main areas of consideration is the fueling of a Supersonic Combusting Ramjet (scramjet) engine. Using Computational Fluid Dynamics (CFD), computer simulations can be performed to analyze the flow physics of a scramjet. In this research, an optimization code, Dakota, is integrated with the CFD to optimize a set of parameters to maximum thrust. In this study, the fuel injection and combustion is replaced with heat sources. This simplification greatly reduces the computational requirements. Additionally, the 3D geometry is reduced to an axisymmetric 2D geometry because three dimension effects like mixing and combustion are not being modeled. With this simplified model, the optimization and CFD algorithm is executed to find the heat addition for maximum thrust. Different optimization methods have been explored to reduce computational times. A genetic algorithm was selected because of its robust abilities. Additionally, a sampling algorithm was selected because of its abilities to explore the whole design space. Furthermore, the sampling method enables additional studies, such as sensitivity studies, to be completed. In addition to optimization studies, calibration studies are performed to obtain the heat source values that correspond to a given experimental wall pressure distribution. Knowledge of the optimized heat distribution will assist in the optimization of fueling splits and injector locations for a more detailed combustion investigation in which similar optimization techniques can be applied.

Download or read book An Innovative 3D CFD Approach towards Virtual Development of Internal Combustion Engines written by Marco Chiodi and published by Springer Science & Business Media. This book was released on 2011-03-07 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the engine development process, simulation and predictive programs have continuously gained in reliance. Due to the complexity of future internal combustion engines the application of simulation programs towards a reliable “virtual engine development” is a need that represents one of the greatest challenges. Marco Chiodi presents an innovative 3D-CFD-tool, exclusively dedicated and optimized for the simulation of internal combustion engines. Thanks to improved or newly developed 3D-CFD-models for the description of engine processes, this tool ensures an efficient and reliable calculation also by using coarse 3D-CFD-meshes. Based on this approach the CPU-time can be reduced up to a factor 100 in comparison to traditional 3D-CFD-simulations. In addition an integrated and automatic “evaluation tool” establishes a comprehensive analysis of the relevant engine parameters. Due to the capability of a reliable “virtual development” of full-engines, this fast response 3D-CFD-tool makes a major contribution to the engine development process. Südwestmetall-Förderpreis 2010

Download or read book PymooCFD a Multi Objective Optimization Framework for CFD written by George Martin Cunningham Love and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern computational resource have solidified the use of computer modeling as an integral part of the engineering design process. This is particularly impressive when it comes to high-dimensional models such as computational fluid dynamics (CFD) models. CFD models are now capable of producing results with a level of confidence that would previously have required physical experimentation. Simultaneously, the development of machine learning techniques and algorithms has increased exponentially in recent years. This acceleration is also due to the widespread availability of modern computational resources. Thus far, the cross-over between these fields has been mostly focused on computer models with low computational costs. However, this is slowly changing through the continued rapid development of both fields. The pymooCFD platform seeks to unite these fields of study by connecting a state-of-the-art library of optimization algorithms with industry leading CFD solvers. To begin with, this platform is important for testing the effectiveness of applying new optimization algorithms to CFD. Additionally, machine learning has been shown to help improve CFD models; this platform could serve to facilitate the development of better CFD models. In this paper, the pymooCFD platform is applied to three different optimization problems. First, for validation purposes, the platform was used to conduct a well documented optimization problem, the reduction of drag around a circular cylinder through oscillating rotation around its central axis. Second, the platform was applied to a Large Eddy Simulation (LES) to Reynolds-Average Navier-Stokes (RANS) model simplification. Lastly, the platform was applied to optimizing the direction, power and location of portable air purifiers in a room with six computer simulated persons (CSPs). The results show that the pymooCFD is a powerful tool for applying optimization algorithms to CFD. The validation of the platform was successful. A novel approach to CFD model simplification, called boundary condition calibration, is proposed. Finally, conclusions were drawn about optimal configuration of portable air purifiers within indoor spaces. These conclusions should serve to inform the experiments need to draw qualitative conclusion and create health advisories. Code Repository: https://github.com/gmclove/pymooCFD

Download or read book Optimization and Computational Fluid Dynamics written by Dominique Thévenin and published by Springer Science & Business Media. This book was released on 2008-01-08 with total page 301 pages. Available in PDF, EPUB and Kindle. Book excerpt: The numerical optimization of practical applications has been an issue of major importance for the last 10 years. It allows us to explore reliable non-trivial configurations, differing widely from all known solutions. The purpose of this book is to introduce the state-of-the-art concerning this issue and many complementary applications are presented.

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 CFD Modeling and Optimization of Fuel cell Systems written by P. L. Zervas and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fuel Cells appear currently as being one of the most promising technologies for power generation, due to the combination of benefits they offer. Fuel-cell systems are environmentally benign, highly efficient, flexible, durable and easy to maintain. The investigation of the impact of various process parameters on fuel cell operation is, thus, of particular importance. Many attempts have been made towards this direction. Among them, a popular and promising approach relies on the application of Computational Fluid Dynamics (CFD) techniques. In this book, the fundamental principles of fuel cells operation and the mathematical formulation of a generic CFD model -including transport and electrochemical phenomena are presented in detail. Sample results that illustrate the validity of the CFD model are presented next. A wide range of process-parameters values is examined, in order to investigate the influence of each one on the performance of the fuel-cell system. In order to reduce the size and improve the flexibility of the CFD model, a database containing the results of many runs is developed and is used to develop a simpler input-output model. The new model explores the highly non-linear relationships and reveals the mathematical correlations that exist between input and output parameters. Finally, nomograms generated from the developed input-output model are presented in detail which turns out to be a useful design tool for engineers interested in Fuel Cell Technology.

Download or read book CFD Error Elimination with Optimal Finite Element Constructions written by A.J. Baker and published by Elsevier. This book was released on 2021-09-15 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: CFD Error Elimination with Optimal Finite Element Constructions contains the theoretical basis, equation development, and algorithm development steps needed to generate a significantly improved AD methodology for CFD users and code developers worldwide. By informing users of the presence of these errors and the possibility that the solution they are obtaining could have embedded errors, this book aims to improve the accuracy of research carried out across fluid mechanics, particularly in turbulence and heat transfer. In general, the field of computational fluid dynamics (CFD) involves the numerical solution of the Navier Stokes equations, the alternate compressible form, and the required constitutive equations to close the solution. These equations are inherently unstable and require some form of artificial dissipation (AD) in order to stabilize the numerical solution. One distinguishing factor in all CFD computer software is how they handle this AD and how accurately the code results compare to known solutions, i.e., validation. The accuracy of all existing methods can be improved and is nowhere near perfect. Addresses a wide range of flows-laminar and turbulent, low speed to high speed-independent of dimensionality Covers several relevant kinds of mathematical operation, discretization, difference algebra, physics-based modeling, and numerical linear algebra Provides all the theoretical and numerical tools needed to optimize your own finite element code

Download or read book IUTAM Symposium on Combustion in Supersonic Flows written by M. Champion and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 413 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the IUTAM Symposium held in Poitiers, France, 2-6 October 1995

Download or read book Scramjet Propulsion written by Dora Musielak and published by John Wiley & Sons. This book was released on 2022-11-16 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scramjet Propulsion Explore the cutting edge of HAP technologies with this comprehensive resource from an international leader in her field Scramjet Propulsion: A Practical Introduction delivers a comprehensive treatment of hypersonic air breathing propulsion and its applications. The book covers the most up-to-date hypersonic technologies, like endothermic fuels, fuel injection and flameholding systems, high temperature materials, and TPS, and offers technological overviews of hypersonic flight platforms like the X-43A, X-51A, and HiFIRE. It is organized around easy-to-understand explanations of technical challenges and provides extensive references for the information contained within. The highly accomplished author provides readers with a fulsome description of the theoretical underpinnings of hypersonic technologies, as well as critical design and technology issues affecting hypersonic air breathing propulsion technologies. The book’s combination of introductory theory and advanced instruction about individual hypersonic engine components is ideal for students and practitioners in fields as diverse as hypersonic vehicle and propulsion development for missile defense technologies, launch aerospaceplanes, and civilian transports. Over 250 illustrations and tables round out the material. Readers will also learn from: A thorough introduction to hypersonic flight, hypersonic vehicle concepts, and a review of fundamental principles in hypersonic air breathing propulsion Explorations of the aerothermodynamics of scramjet engines and the design of scramjet components, as well as hypersonic air breathing propulsion combustors and fuels Analyses of dual-mode combustion phenomena, materials structures, and thermal management in hypersonic vehicles, and combined cycle propulsion An examination of CFD analysis, ground and flight testing, and simulation Perfect for researchers and graduate students in aerospace engineering, Scramjet Propulsion: A Practical Introduction is also an indispensable addition to the libraries of engineers working on hypersonic vehicle development seeking a state-of-the-art resource in one of the most potentially disruptive areas of aerospace research today.

Download or read book A Variable Complexity Modeling Approach to Scramjet Fuel Injection Array Design Optimization written by Michael D. Payne and published by . This book was released on 1998-03-01 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: The analysis of fuel air mixing in a scramjet is often accomplished either with Computational Fluid Dynamics (CFD) algorithms or through experimental research. These approaches, while accurate and reliable, are extremely expensive and thus not well suited for use with conventional design optimization methods. In this investigation, Variable Complexity Modeling (VCM) is used to significantly reduce the number of complex, expensive analyses required to optimize the design of a scramjet fuel injection array. A design problem formulation for a lateral transverse injection array is developed and a VCM approach to design optimization is conducted in two stages. Initially, a simplified analysis model is used to provide relatively inexpensive predictions of design fuel air mixing characteristics. A parametric analysis is conducted to explore the design region, and a preliminary optimal design is found using both Sequential Quadratic Programming and a Genetic Algorithm. In the second stage, response surface methodology is supplemented with preliminary stage information to minimize the number of expensive analyses required to finalize the design. It is shown that only 25 design evaluations are required to develop a near optimal design.

Download or read book Optimization of a 2D Scramjet vehicle Using CFD and Simplified Approximate Flow Analysis Techniques written by Peter D. McQuade and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of an Efficient 3 D CFD Software to Simulate and Visualize the Scavenging of a Two stroke Engine written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The two-stroke engine is widely used in many different devices. But the environmentally problematic exhaust characteristic is a big drawback of this type of engine. In the scavenging process, when the fresh charge displaces the exhaust gas in the cylinder, lies the biggest opportunity to improve the exhaust data by geometry optimization. Therefore, we developed a software package to efficiently simulate the three-dimensional, time-dependent, Navier-Stokes equations within the complex, real-world geometry of the two-stroke engine with moving piston and rotating crankshaft. Due to the high temperature in the cylinder after combustion, a temperature dependent treatment of the material constants is necessary. Adaptive local time-stepping and dynamic local mesh adaption, as well as parallelization of the code, are used to speed up the computation time considerably. The software has been extensively validated and has been applied to the problem of short-circuiting in two-stroke engines.

Download or read book Computational Fluid Dynamics in Support of Development and Optimization of the Massachusetts Institute of Technology Research Reactor Low enriched Uranium Fuel Element Design written by Mihai Aurelian Diaconeasa and published by . This book was released on 2014 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of lateral power distribution of the MITR LEU fuel design was analyzed using Computational Fluid Dynamics. Coupled conduction and convective heat transfer were modeled for uniform and non-uniform lateral power distributions. It was concluded that, due to conduction, the maximum heat flux ratio on the cladding surface is 1.16, compared to the maximum volumetric power generation ratio of 1.23. The maximum cladding temperature occurs roughly 0.5 inches from the edge of the support plate, while the peak volumetric power generation is located at the end of the fuel meat, about 0.1 inches from the edge of the support plate. Although the heat transfer coefficient is lower in the corner of the coolant channel, this has a negligible effect on the peak cladding temperature, i.e. the peak cladding temperature is related to heat flux only and a "channel average" heat transfer coefficient can be adopted. Moreover, coolant temperatures in the radial direction are reasonably uniform, which is indicative of good lateral mixing. Finally, a quasi-DNS study has been performed to analyze the effect of the fuel grooves on the local heat transfer coefficient. The quasi-DNS results bring useful insights, showing two main effects related to the existence of the grooves. First, the increased surface leads to an increase in the pressure drop and further, the flow aligned configuration of the grooves limits the ability of the near wall turbulent structures to create mixing, leading to a noticeable reduction in the local heat transfer coefficient at the base of the grooves. Overall, this leads to an effective decrease in the local heat transfer coefficient, but due to the increased heat transfer surface the global heat transfer is enhanced in comparison to the flat plate configuration. The improved understanding of the effects of grooves on the local heat transfer phenomena provides a useful contribution to future fuel design considerations. For example, the increase in pressure drop, together with the reduction in the local heat transfer coefficient indicated that the selection of a grooved wall channel instead of a smooth wall channel might not necessarily be optimal, particularly if fabrication issues are taken into account, together with the concern that grooved walls may promote oxide growth and crud formation during the life of the fuel.

Download or read book Optimization of Fuel air Mixing for a Scramjet Combustor Geometry Using CFD and a Genetic Algorithm written by and published by . This book was released on 2008 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 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 974 pages. Available in PDF, EPUB and Kindle. Book excerpt: