Download or read book Numerical Simulation of Polydisperse Two phase Turbulent Jets written by Jorge M. M. Barata and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Simulations of Multiphase Turbulent Jets written by Thomas Gabriel Almeida and published by . This book was released on 2004 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Simulation of Turbulent Jets with Rectangular Cross Section written by Robert V. Wilson and published by . This book was released on 1997 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three-dimensional turbulent jets with rectangular cross-section are simulated with a finite-difference numerical method. The full Navier-Stokes equations are solved at low Reynolds numbers, whereas at the high Reynolds numbers filtered forms of the equations are solved along with a subgrid scale model to approximate effects of the unresolved scales. A 2-N storage, third-order Runge-Kutta scheme is used for temporal discretization and a fourth-order compact scheme is used for spatial discretization. Computations are performed for different inlet conditions which represent different types of jet forcing. The phenomenon of axis-switching is observed, and it is confirmed that this is based on self-induction of the vorticity field. Budgets of the mean streamwise velocity show that convection is balanced by gradients of the Reynolds stresses and the pressure.
Download or read book Numerical Simulation of Turbulent Jets with Rectangular Cross section written by Robert V. Wilson and published by . This book was released on 1997 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling and Simulation of Turbulent Mixing and Reaction written by Daniel Livescu and published by Springer Nature. This book was released on 2020-02-19 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights recent research advances in the area of turbulent flows from both industry and academia for applications in the area of Aerospace and Mechanical engineering. Contributions include modeling, simulations and experiments meant for researchers, professionals and students in the area.
Download or read book Mathematical Modelling and Numerical Simulations of Chemically Reacting Turbulent Jets written by Kian Mehravaran and published by . This book was released on 2005 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Calculation of Two phase Turbulent Jets written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-phase turbulent round jets were numerically simulated using a multidimensional two-phase CFD code based on the two-fluid model. The turbulence phenomena were treated with the standard k-[epsilon] model. It was modified to take into account the additional dissipation of turbulent kinetic energy by the dispersed phase. Within the context of the two-fluid model it is more appropriate and physically justified to treat the diffusion by an interfacial force in the momentum equation. In this work, the diffusion force and the additional dissipation effect by the dispersed phase were modeled starting from the classical turbulent energy spectrum analysis. A cut-off frequency was proposed to decrease the dissipation effect by the dispersed phase when large size particles are introduced in the flow. The cut-off frequency combined with the bubble-induced turbulence effect allows for an increase in turbulence for large particles. Additional care was taken in choosing the right kind of experimental data from the literature so that a good separate effect test was possible for their models. The models predicted the experimental data very closely and they were general enough to predict extreme limit cases: water-bubble and air-droplet jets.
Download or read book Experiments and Numerical Simulations of Turbulent Combustion of Diluted Sprays written by Bart Merci and published by Springer Science & Business Media. This book was released on 2014-03-27 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reflects the results of the 2nd and 3rd International Workshops on Turbulent Spray Combustion. The focus is on progress in experiments and numerical simulations for two-phase flows, with emphasis on spray combustion. Knowledge of the dominant phenomena and their interactions allows development of predictive models and their use in combustor and gas turbine design. Experts and young researchers present the state-of-the-art results, report on the latest developments and exchange ideas in the areas of experiments, modelling and simulation of reactive multiphase flows. The first chapter reflects on flame structure, auto-ignition and atomization with reference to well-characterized burners, to be implemented by modellers with relative ease. The second chapter presents an overview of first simulation results on target test cases, developed at the occasion of the 1st International Workshop on Turbulent Spray Combustion. In the third chapter, evaporation rate modelling aspects are covered, while the fourth chapter deals with evaporation effects in the context of flamelet models. In chapter five, LES simulation results are discussed for variable fuel and mass loading. The final chapter discusses PDF modelling of turbulent spray combustion. In short, the contributions in this book are highly valuable for the research community in this field, providing in-depth insight into some of the many aspects of dilute turbulent spray combustion.
Download or read book Numerical Simulation of Particle Dispersion in Turbulent Jets written by J. J. Lienau and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Similarity Solution of a Second order Model of Free Turbulent Jets with a Passive Scalar Contaminant and Its Applicability to Two phase Jets written by Brian Ronald Cunningham and published by . This book was released on 1980 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Simulation and Spectral Modal Analysis of Nonlinear Dynamics and Acoustics in Turbulent Jets written by Akhil Nekkanti and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulent jets are canonical flows that occur when fluid emerges from an orifice into the surrounding environment, such as the jet from aircraft engines. As the fluid emerges from the nozzle, it forms an unstable shear layer that grows very rapidly, forming large-scale coherent structures, which are the main sources of aft-angle jet noise. The mechanism behind the generation of jet noise is still not fully understood. Further insights into characteristics of coherent structures can aid our understanding of turbulence, and in modeling and controlling various mechanisms. The development of techniques for the education of coherent structures is another objective of this work.The main foci of this work are: (i) performing high-fidelity numerical simulations of turbulent jets and extracting physical insights from coherent flow structures, and (ii) developing techniques that extract these flow structures from the large dataset generated by these simulations. In recent years, spectral proper orthogonal decomposition (SPOD) has emerged as a major tool for extracting coherent structures. In the first part, we extend SPOD for low-rank reconstruction, denoising, prewhitenening, frequency-time analysis, and gappy-data reconstruction. Two approaches for flow-field reconstruction are proposed, a frequency-domain approach, and a time-domain approach. A SPOD-based denoising strategy is also presented, which achieves significant noise reduction while facilitating drastic data compression. A convolution-based strategy is proposed for frequency-time analysis that characterizes the intermittency of spatially coherent flow structures. When applied to the turbulent jet data, SPOD-based frequency-time analysis reveals that the intermittent occurrence of large-scale coherent structures is directly associated with high-energy events. Lastly, a new algorithm, gappy-SPOD, is developed that leverages the space-time correlation of SPOD modes to estimate missing data. Even for highly chaotic flows with up to 20% missing data, our method facilitates that structures associated with different time scales are well-estimated in the missing regions. For the cases considered here, it outperforms established techniques such as gappy-POD and Kriging. In the second part, we investigate the nonlinear dynamics and controllability of coherent structures by actuating them. Large-eddy simulations (LES) of two unforced and four forced jets at Re = 50,000 and M_j = 0.4 were performed. The two unforced jets include an initially laminar and a turbulent jet. All four forced jets are turbulent and are forced at the azimuthal wavenumbers m=0, m=±1, m=±2, and m=±6. The unforced and forced jets were validated with companion experiments. Compared to the turbulent jet, the initially laminar jet develops later but at a faster rate, which is a result of the vortex pairing in the shear layer. The emphasis of the analysis is on characterizing the vortex pairing and the associated nonlinear energy transfer. Here, for the first time, we evaluate the spectral energy budget based on the leading modes of the SPOD. Our analysis reveals that energy flows from the fundamental to its subharmonic, resulting in the growth of the subharmonic. These results provide evidence for a previously suggested parametric resonance mechanism. In the forced jets, we examine the effect of forcing using a recently proposed method, bispectral mode decomposition (BMD), which extracts flow structures associated with nonlinear triadic interactions. We use BMD to construct a cascade of triads and find that the most dominant triads arise due to fundamental self-interaction and second-harmonic-fundamental difference interaction. Furthermore, our analysis of the far-field in the unforced and m=0-forced jets sheds light on the crucial role of difference-interactions in the generation of jet noise.
Download or read book Statistical Treatment of Turbulent Polydisperse Particle Systems written by J.S. Shrimpton and published by Springer. This book was released on 2014-06-20 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book we will introduce the modeling process of turbulent particulate flows which are encountered in many engineering and environmental applications. These types of flows usually also involve heat and mass transfer and turbulence adds another dimension to the complexity of the problem and hence a rigorous mathematical treatment is usually required. This required mathematical background makes the learning curve for new research students and practicing engineers extremely steep. Therefore modeling process for new or existing problems is extremely slow and is usually restricted to minor improvements to the to the available models. In this book we try to gather the required mathematical knowledge and introduce them more intuitively. Many numerical simulations of basic processes and equation will be given to provide the reader with a physical understanding of the different terms in the underlying equations. We will start the modeling process from a mesoscopic level which deals with the system of an intermediate length scale between the size of the atoms or molecules and the bulk of the material. This provides a unique opportunity for the reader to intuitively add different phenomena to their models and equipped with the necessary mathematical tools derive the final models for their problems.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 1032 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fuel Injection in Automotive Engineering written by Kazimierz Lejda and published by BoD – Books on Demand. This book was released on 2012-04-20 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main topic of "Fuel injection in automotive engineering" book is fundamental process that determines the development of internal combustion engines and performances of automotive vehicles. The book collects original works focused on up-to-date issues relevant to improving injection phenomena per se and injection systems as the engine key components.
Download or read book Studies in Two phase Turbulence Closure Modeling written by Chien-Pin Chen and published by . This book was released on 1983 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Simulation of Shock Enhanced Mixing in Axisymmetric Turbulent Jets written by S. Obata and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Computational Study of Spatially Evolving Turbulent Plane Jets written by Scott Alan Stanley and published by . This book was released on 1998 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:
