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Turbulence Modeling Of Strongly Heated Internal Pipe Flow Using Large Eddy Simulation
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Book Synopsis Turbulence Modeling of Strongly Heated Internal Pipe Flow Using Large Eddy Simulation by : Michal Hradisky
Download or read book Turbulence Modeling of Strongly Heated Internal Pipe Flow Using Large Eddy Simulation written by Michal Hradisky and published by . This book was released on 2011 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main objective of this study was to evaluate the performance of the three Large Eddy Simulation (LES) subgrid scale (SGS) models on a strongly heated, low Mach number upward gas flow in a vertical pipe with forced convection. The models chosen for this study were the Smagorinsky-Lilly Dynamic model (SLD), the Kinetic Energy Transport model (KET), and the Wall-Adaptive Local-Eddy viscosity model (WALE). The used heating rate was sufficiently large to cause properties to vary significantly in both the radial and streamwise directions. All simulations were carried out using the commercial software FLUENT. The effect of inlet turbulence generation techniques was considered as well. Three inlet turbulence generation techniques were compared, namely, the Spectral Synthesizer Method (SSM), the Vortex Method (VM), and the Generator (GEN) technique. A user-defined function (EDF) was written to implement the GEN technique into the solver; the SSM and VM techniques were already build-in. All simulation and solver settings were validated by performing computational simulations of isothermal fully developed pipe flow and results were compared to available experimental and Direct Numerical Simulation (DNS) data. For isothermal boundary conditions, among the three inlet turbulence generation techniques, the GEN technique produced results which best matched the experimental and DNS results. All three LES SGS models performed equally well when coupled with the GEN technique for the study of isothermal pipe flow. However, all models incorrectly predicted the behavior of radial and circumferential velocity fluctuations near the wall and the GEN technique proved to be the most computationally expensive. For simulations with longer computational domain, the effect of the inlet turbulence generation technique diminishes. However, results suggest that both the SLD and KET models need shorter computational domains to recover proper LES behavior when coupled with the VM technique in comparison to the WALE SGS model with the same turbulence inlet generation technique. For high heat flux simulations all SGS models were coupled with the VM technique to decrease the computational effort to obtain statistically steady-state solution. For comparative purposes, one simulation was carried out using the WALE and GEN techniques. All simulations equally significantly underpredicted the streamwise temperature distribution along the pipe wall as well as in the radial directions at various streamwise locations. These effects are attributed to the overpredicted streamwise velocity components and incorrect behavior of both the radial and circumferential velocity components in the near wall region for all subgrid scale models.
Book Synopsis Engineering Turbulence Modelling and Experiments 5 by : W. Rodi
Download or read book Engineering Turbulence Modelling and Experiments 5 written by W. Rodi and published by Elsevier. This book was released on 2002-08-21 with total page 1029 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulence is one of the key issues in tackling engineering flow problems. As powerful computers and accurate numerical methods are now available for solving the flow equations, and since engineering applications nearly always involve turbulence effects, the reliability of CFD analysis depends increasingly on the performance of the turbulence models. This series of symposia provides a forum for presenting and discussing new developments in the area of turbulence modelling and measurements, with particular emphasis on engineering-related problems. The papers in this set of proceedings were presented at the 5th International Symposium on Engineering Turbulence Modelling and Measurements in September 2002. They look at a variety of areas, including: Turbulence modelling; Direct and large-eddy simulations; Applications of turbulence models; Experimental studies; Transition; Turbulence control; Aerodynamic flow; Aero-acoustics; Turbomachinery flows; Heat transfer; Combustion systems; Two-phase flows. These papers are preceded by a section containing 6 invited papers covering various aspects of turbulence modelling and simulation as well as their practical application, combustion modelling and particle-image velocimetry.
Book Synopsis Engineering Turbulence Modelling and Experiments 6 by : Wolfgang Rodi
Download or read book Engineering Turbulence Modelling and Experiments 6 written by Wolfgang Rodi and published by Elsevier. This book was released on 2005-05-05 with total page 1011 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the world renowned ERCOFTAC (International Symposium on Engineering Turbulence Modelling and Measurements). The proceedings include papers dealing with the following areas of turbulence: · Eddy-viscosity and second-order RANS models · Direct and large-eddy simulations and deductions for conventional modelling · Measurement and visualization techniques, experimental studies · Turbulence control · Transition and effects of curvature, rotation and buoyancy on turbulence · Aero-acoustics · Heat and mass transfer and chemically reacting flows · Compressible flows, shock phenomena · Two-phase flows · Applications in aerospace engineering, turbomachinery and reciprocating engines, industrial aerodynamics and wind engineering, and selected chemical engineering problems Turbulence remains one of the key issues in tackling engineering flow problems. These problems are solved more and more by CFD analysis, the reliability of which depends strongly on the performance of the turbulence models employed. Successful simulation of turbulence requires the understanding of the complex physical phenomena involved and suitable models for describing the turbulent momentum, heat and mass transfer. For the understanding of turbulence phenomena, experiments are indispensable, but they are equally important for providing data for the development and testing of turbulence models and hence for CFD software validation. As in other fields of Science, in the rapidly developing discipline of turbulence, swift progress can be achieved only by keeping up to date with recent advances all over the world and by exchanging ideas with colleagues active in related fields.
Book Synopsis Large Eddy Simulation of Compressible Turbulent Channel and Annular Pipe Flows with System and Wall Rotations by : Joon Sang Lee
Download or read book Large Eddy Simulation of Compressible Turbulent Channel and Annular Pipe Flows with System and Wall Rotations written by Joon Sang Lee and published by . This book was released on 2004 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: The compressible filtered Navier-Stokes equations were solved using a second order accurate finite volume method with low Mach number preconditioning. A dynamic subgrid-scale stress model accounted for the subgrid-scale turbulence. The study focused on the effects of buoyancy and rotation on the structure of turbulence and transport processes including heat transfer. Several different physical arrangements were studied as outlined below. The effects of buoyancy were first studied in a vertical channel using large eddy simulation (LES). The walls were maintained at constant temperatures, one heated and the other cooled. Results showed that aiding and opposing buoyancy forces emerge near the heated and cooled walls, respectively. In the aiding flow, the turbulent intensities and heat transfer were suppressed at large values of Grashof number. In the opposing flow, however, turbulence was enhanced with increased velocity fluctuations. Another buoyancy study considered turbulent flow in a vertically oriented annulus. Isoflux wall boundary conditions with low and high heating were imposed on the inner wall while the outer wall was adiabatic. The results showed that the strong heating and buoyancy force caused distortions of the flow structure resulting in reduction of turbulent intensities, shear stress, and turbulent heat flux, particularly near the heated wall. Flow in an annular pipe with and without an outer wall rotation about its axis was first investigated at moderate Reynolds numbers. When the outer pipe wall was rotated, a significant reduction of turbulent kinetic energy was realized near the rotating wall. Secondly, a large eddy simulation has been performed to investigate the effect of swirl on the heat and momentum transfer in an annular pipe flow with a rotating inner wall. The simulations indicated that the Nusselt number and the wall friction coefficient increased with increasing rotation speed of the wall. It was also observed that the axial velocity profile became flattened and turbulent intensities were enhanced due to swirl. As a part of the study of rotation effects, a large eddy simulation of a rotating ribbed channel flow with the heat transfer was investigated. The rotation axis was parallel to the spanwise direction of the parallel plate channel. Uniform heat flux was applied to the channel for two rates of rotation. The results showed that near the stable (leading) side, the turbulent intensities and heat transfer were suppressed, but turbulence was enhanced with increasing shear stress and turbulent kinetic energy near the unstable (trailing) side.
Book Synopsis Direct and Large-eddy Simulation XI by : Maria Vittoria Salvetti
Download or read book Direct and Large-eddy Simulation XI written by Maria Vittoria Salvetti and published by . This book was released on 2019 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers the proceedings of the 11th workshop on Direct and Large Eddy Simulation (DLES), which was held in Pisa, Italy in May 2017. The event focused on modern techniques for simulating turbulent flows based on the partial or full resolution of the instantaneous turbulent flow structures, as Direct Numerical Simulation (DNS), Large-Eddy Simulation (LES) or hybrid models based on a combination of LES and RANS approaches. In light of the growing capacities of modern computers, these approaches have been gaining more and more interest over the years and will undoubtedly be developed and applied further. The workshop offered a unique opportunity to establish a state-of-the-art of DNS, LES and related techniques for the computation and modeling of turbulent and transitional flows and to discuss about recent advances and applications. This volume contains most of the contributed papers, which were submitted and further reviewed for publication. They cover advances in computational techniques, SGS modeling, boundary conditions, post-processing and data analysis, and applications in several fields, namely multiphase and reactive flows, convection and heat transfer, compressible flows, aerodynamics of airfoils and wings, bluff-body and separated flows, internal flows and wall turbulence and other complex flows.
Book Synopsis Large Eddy Simulation for Incompressible Flows by : P. Sagaut
Download or read book Large Eddy Simulation for Incompressible Flows written by P. Sagaut and published by Springer Science & Business Media. This book was released on 2005-12-11 with total page 575 pages. Available in PDF, EPUB and Kindle. Book excerpt: First concise textbook on Large-Eddy Simulation, a very important method in scientific computing and engineering From the foreword to the third edition written by Charles Meneveau: "... this meticulously assembled and significantly enlarged description of the many aspects of LES will be a most welcome addition to the bookshelves of scientists and engineers in fluid mechanics, LES practitioners, and students of turbulence in general."
Book Synopsis Improved Turbulence Models Based on Large Eddy Simulation of Homogeneous, Incompressible, Turbulent Flows by : Stanford University. Thermosciences Division. Thermosciences Division
Download or read book Improved Turbulence Models Based on Large Eddy Simulation of Homogeneous, Incompressible, Turbulent Flows written by Stanford University. Thermosciences Division. Thermosciences Division and published by . This book was released on 1983 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: The physical bases of large eddy simulation and the subgrid scale modeling it employs are studied in some detail. This investigation leads to a new scale-similarity model for the subgrid-scale turbulent Reynolds stresses.
Book Synopsis Large-Eddy Simulations of Turbulence by : M. Lesieur
Download or read book Large-Eddy Simulations of Turbulence written by M. Lesieur and published by Cambridge University Press. This book was released on 2005-08-22 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Large-Eddy Simulations of Turbulence is a reference for LES, direct numerical simulation and Reynolds-averaged Navier-Stokes simulation.
Book Synopsis Large Eddy Simulation of Wall Bounded Turbulent Flows with Heat Transfer by : Yang Liu
Download or read book Large Eddy Simulation of Wall Bounded Turbulent Flows with Heat Transfer written by Yang Liu and published by . This book was released on 2002 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis work, large eddy simulation was used to study a variety of wall-bounded turbulent flows using a compressible finite volume formulation. Subgrid scale terms in both momentum and energy equations were modeled dynamically. Furthermore, due to the inhomogeniety of wall-bounded flows, the model was further localized to better represent the physics of the problem. The model was first applied to study the incompressible turbulent flow through a duct with square cross-section. Mean flow, law of the wall, and turbulence statistics were compared with the benchmark results of direct numerical simulation and excellent agreement was achieved. The secondary flow in the cross-section was captured. It is composed of four pairs of counter-rotating cells. The interaction between mean and secondary flow fields creates some important features and they were studied in this work. Based on incompressible duct flow, system rotation was applied to investigate the effects of rotation on the turbulent flow field. The system rotation was found to reduce turbulence level on the leading side, while increase turbulence level on the trailing side. Because of the rotation, the secondary flow field in non-rotating duct was found to be diminished at weaker rotation and even eliminated at stronger rotation. Instead, a pair of counter rotating cells called Taylor-Görtler vortices, as well as the Taylor-Proudman regime, was found to exist in the cross-section, which is consistent with the results of the literature. Large eddy simulation was also applied to investigate the effects of ribs and system rotation on heat transfer in a channel. It was found that a rib creates recirculation zones near the rib. The turbulence level is at its maximum near the ribs. The existence of ribs enhances heat transfer significantly over the plane channel, as well as creates low-heat-transfer-coefficient region in the recirculation zones. This means a balance is needed between global enhancement and local suppression. With system rotation, heat transfer is greatly enhanced on the trailing side, while significantly reduced on the leading side.
Book Synopsis Large Eddy Simulation Based Turbulent Flow-induced Vibration of Fully Developed Pipe Flow by : Matthew Thurlow Pittard
Download or read book Large Eddy Simulation Based Turbulent Flow-induced Vibration of Fully Developed Pipe Flow written by Matthew Thurlow Pittard and published by . This book was released on 2003 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flow-induced vibration caused by fully developed pipe flow has been recognized, but not fully investigated under turbulent conditions. This thesis focuses on the development of a numerical Fluid-Structure Interaction (FSI) model that will help define the relationship between pipe wall vibration and the physical characteristics of turbulent flow. Commercial FSI software packages are based on Reynolds Averaged Navier-Stokes (RANS) fluid models, which do not compute the instantaneous fluctuations in turbulent flow. This thesis presents an FSI approach based on Large Eddy Simulation (LES) flow models, which do compute the instantaneous fluctuations in turbulent flow. The results based on the LES models indicate that these fluctuations contribute to the pipe vibration. It is shown that there is a near quadratic relationship between the standard deviation of the pressure field on the pipe wall and the flow rate. It is also shown that a strong relationship between pipe vibration and flow rate exists. This research has a direct impact on the geothermal, nuclear, and other fluid transport industries.
Author :Luigi Carlo Berselli Publisher :Springer Science & Business Media ISBN 13 :9783540263166 Total Pages :378 pages Book Rating :4.2/5 (631 download)
Book Synopsis Mathematics of Large Eddy Simulation of Turbulent Flows by : Luigi Carlo Berselli
Download or read book Mathematics of Large Eddy Simulation of Turbulent Flows written by Luigi Carlo Berselli and published by Springer Science & Business Media. This book was released on 2006 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: The LES-method is rapidly developing in many practical applications in engineering The mathematical background is presented here for the first time in book form by one of the leaders in the field
Book Synopsis Unsteady Turbulent Flow Modelling and Applications by : David Roos Launchbury
Download or read book Unsteady Turbulent Flow Modelling and Applications written by David Roos Launchbury and published by Springer. This book was released on 2016-01-28 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: The master thesis of David Roos Launchbury deals with the implementation and validation of a numerical solver for incompressible large eddy simulation (LES) with heat transfer in OpenFOAM. Academic and industrial cases, ranging from flow between parallel plates to film cooling, are investigated utilising existing and newly-implemented turbulence models. Simulations using no turbulence models, i.e. under-resolved DNS (UDNS) simulations, are performed for comparison. Very good results are obtained in all cases with variations among the individual models, with the UDNS simulations performing surprisingly well. The study shows that the developed software is able to simulate complex cases reliably and accurately.
Book Synopsis Large Eddy Simulation of Compressible Turbulent Pipe Flow with Heat Transfer by : Xiaofeng Xu
Download or read book Large Eddy Simulation of Compressible Turbulent Pipe Flow with Heat Transfer written by Xiaofeng Xu and published by . This book was released on 2003 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: A compressible finite volume formulation for large eddy simulation (LES) of turbulent channel flows was extended to solve the turbulent flows in pipes and annular passages. A general finite volume scheme was developed based on conservation equations in Cartesian coordinates with non-Cartesian control volumes. A dual-time stepping approach with time derivative preconditioning was employed and time marching was done with an implicit lower-upper-symmetric-Gauss-Seidel (LU-SGS) scheme. The small scale motions were modeled by a dynamic subgrid-scale (SGS) model. The code was developed in a multiblock framework and parallelized using the message passing interface (MPI). The finite volume LES formulation was validated by simulating the isothermal fully developed turbulent pipe and annular flows. The results were compared to experimental data and direct numerical simulation (DNS) results. The LES formulation was further validated by the simulation of turbulent pipe flows with low heat transfer and comparisons with passive scalar DNS results. Finally, buoyancy forces were added into the LES formulation to simulate mixed convection in a vertical pipe with constant high wall heat fluxes leading to significant property variations. Step-periodic boundary conditions were studied and implemented. The results were validated by comparing with experimental results. Heating effects and flow laminarization were studied. Excellent agreement with DNS and experimental results were obtained for isothermal turbulent pipe and annular flows. The mean temperature profile for the turbulent pipe flow with low heat transfer matched very well with the DNS passive scalar results. Good matches to constant property correlations were also achieved for friction coefficients and Nusselt numbers. For the mixed convection in a vertical pipe, good agreement with the experimental mean streamwise velocity and temperature profiles was obtained. High heating tended to suppress the turbulent intensities and attenuate the turbulent kinetic energy. The thinner viscous layer led to a larger Nusselt numbers which indicated a higher heat transfer rate. Laminarization phenomena were observed along with large overprediction of friction coefficients and underprediction of Nusselt numbers when comparing to fully turbulent property variation correlations.
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:
Book Synopsis New Tools in Turbulence Modelling by : Olivier Metais
Download or read book New Tools in Turbulence Modelling written by Olivier Metais and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical large-eddy simulation techniques are booming at present and will have a decisive impact on industrial modeling and flow control. The book represents the general framework in physical and spectral space. It also gives the recent subgrid-scale models. Topics treated include compressible turbulence research, turbulent combustion, acoustic predictions, vortex dynamics in non-trivial geometries, flows in nuclear reactors and problems in atmospheric and geophysical sciences. The book addresses numerical analysts, physicists, and engineers.
Book Synopsis Development of Large Eddy Simulation Turbulence Models by : Eric Pomraning
Download or read book Development of Large Eddy Simulation Turbulence Models written by Eric Pomraning and published by . This book was released on 2000 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Large-eddy Simulation of Turbulent Flow Using the Finite Element Method by :
Download or read book Large-eddy Simulation of Turbulent Flow Using the Finite Element Method written by and published by . This book was released on 1995 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: The equations of motion describing turbulent flows (in both the low and high Reynolds-number regimes) are well established. However, present day computers cannot meet the enormous computational requirement for numerically solving the governing equations for common engineering flows in the high Reynolds number turbulent regime. The characteristics that make turbulent, high Reynolds number flows difficult to simulate is the extreme range of time and space scales of motion. Most current engineering calculations are performed using semi-empirical equations, developed in terms of the flow mean (average) properties. These turbulence{open_quote} models{close_quote} (semi-empirical/analytical approximations) do not explicitly account for the eddy structures and thus, the temporal and spatial flow fluctuations are not resolved. In these averaging approaches, it is necessary to approximate all the turbulent structures using semi-empirical relations, and as a result, the turbulence models must be tailored for specific flow conditions and geometries with parameters obtained (usually) from physical experiments. The motivation for this research is the development of a finite element turbulence modeling approach which will ultimately be used to predict the wind flow around buildings. Accurate turbulence models of building flow are needed to predict the dispersion of airborne pollutants. The building flow turbulence models used today are not capable of predicting the three-dimensional separating and reattaching flows without the manipulation of many empirical parameters. These empirical parameters must be set by experimental data and they may vary unpredictably with building geometry, building orientation, and upstream flow conditions.
