Download or read book Direct numerical simulation of turbulent pipe flow using Fourier Bessel expansion written by Andrew Thomas Duggleby and published by . This book was released on 2004 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Direct Numerical Simulation of Incompressible Pipe Flow Using a B spline Spectral Method written by Patrick Loulou and published by . This book was released on 1996 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced Turbulent Flow Computations written by Roger Peyret and published by Springer. This book was released on 2014-05-04 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book collects the lecture notes concerning the IUTAM School on Advanced Turbulent Flow Computations held at CISM in Udine September 7–11, 1998. The course was intended for scientists, engineers and post-graduate students interested in the application of advanced numerical techniques for simulating turbulent flows. The topic comprises two closely connected main subjects: modelling and computation, mesh pionts necessary to simulate complex turbulent flow.

Download or read book Direct Numerical Simulation of Curved Turbulent Channel Flow written by Robert deLancey Moser and published by . This book was released on 1984 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Direct Numerical Simulation of Turbulent Flow and Heat Transfer in a Concentric Annular Pipe written by Edris Bagheri and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, the effects of computational domain size and radius ratio on fully developed turbulent flow and heat transfer in a concentric annular pipe are investigated using direct numerical simulation (DNS). To perform DNS, a new parallel computer code based on the pseudo-spectral method was developed using the FORTRAN 90/95 programing languages and the message passing interface (MPI) libraries. In order to study the effects of computational domain size on the turbulence statistics, twelve test cases of different domain sizes are compared. The effects of radius ratio are investigated through a systematic study based on four radius ratios of a concentric pipe. The characteristics of the velocity and temperature fields are examined at two Reynolds number of Re_(D_h ) =8900$ and 17700. The radius ratio affects the interaction of two boundary layers of the concentric annular pipe and has a significant impact on the turbulent flow structures and dynamics. The characteristics of the flow and temperature fields are investigated in both physical and spectral spaces, which include the analyses of the first- and second-order statistical moments, budget balance of the transport equation of Reynolds stresses, two-point correlation coefficients, and premultiplied spectra of velocity, vorticity, and temperature fluctuations. It is observed that the scales and dynamics of turbulence structures vary with the radius ratio as well as the surface curvature of the concave and convex walls. The characteristic length scales of the turbulence structures are identified through a spectral analysis.

Download or read book Analysis of Weakly Compressible Turbulence Using Symmetry Methods and Direct Numerical Simulation written by Raphael Gotthard Harald Arlitt and published by Cuvillier Verlag. This book was released on 2005 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Direct Numerical Simulation of Incompressible Pipe Flow Using a B Spline Spectral Method written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: A numerical method based on b-spline polynomials was developed to study incompressible flows in cylindrical geometries. A b-spline method has the advantages of possessing spectral accuracy and the flexibility of standard finite element methods. Using this method it was possible to ensure regularity of the solution near the origin, i.e. smoothness and boundedness. Because b-splines have compact support, it is also possible to remove b-splines near the center to alleviate the constraint placed on the time step by an overly fine grid. Using the natural periodicity in the azimuthal direction and approximating the streamwise direction as periodic, so-called time evolving flow, greatly reduced the cost and complexity of the computations. A direct numerical simulation of pipe flow was carried out using the method described above at a Reynolds number of 5600 based on diameter and bulk velocity. General knowledge of pipe flow and the availability of experimental measurements make pipe flow the ideal test case with which to validate the numerical method. Results indicated that high flatness levels of the radial component of velocity in the near wall region are physical; regions of high radial velocity were detected and appear to be related to high speed streaks in the boundary layer. Budgets of Reynolds stress transport equations showed close similarity with those of channel flow. However contrary to channel flow, the log layer of pipe flow is not homogeneous for the present Reynolds number. A topological method based on a classification of the invariants of the velocity gradient tensor was used. Plotting iso-surfaces of the discriminant of the invariants proved to be a good method for identifying vortical eddies in the flow field. Loulou, Patrick and Moser, Robert D. and Mansour, Nagi N. and Cantwell, Brian J. Ames Research Center DIGITAL SIMULATION; COMPUTERIZED SIMULATION; COMPUTATIONAL FLUID DYNAMICS; INCOMPRESSIBLE FLOW; PIPE FLOW; FINITE ELEMENT METHOD; TURBULENT FLOW; ...

Download or read book Higher level Simulations of Turbulent Flows written by J. H. Ferziger and published by . This book was released on 1981 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: The five major categories of this paper are: Correlations, Integral methods, Reynolds-averaged equations, large eddy simulation, and full simulation.

Download or read book Direct Numerical Simulation of Turbulent Flow and Heat Transfer Within a Spanwise rotating Elliptical Pipe written by Rafael Hurtado Rosas and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Direct Numerical Simulations of Turbulent Pipe Flow on Parallel Computers written by Jonathan Tal and published by . This book was released on 1995 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Direct Numerical Simulations of Turbulent Pipe Flow with 90 Bends written by Zhixin Wang and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Direct Numerical Simulation of Turbulent Flow in a Circular Pipe Subjected to Radial System Rotation written by Zhao-Ping Zhang and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, direct numerical simulations have been preformed with a high-order spectral element method computer code to investigate the Coriolis force effect on a fully-developed turbulent flow confined within a circular pipe subjected to radial system rotations. In order to study the radially rotating effects on the flow, a wide range of rotation numbers have been tested. In response to the system rotation imposed, large-scale secondary flows appear as streamwise counter-rotating vortices, which highly interact with the boundary layer and have a significant impact on the turbulent flow structures and dynamics. A quasi Taylor-Proudman region occurs at low rotation numbers, where the mean axial velocity is invariant along the rotating axis. As the rotation number increases, laminarization occurs near the bottom wall of the pipe, and the flow become fully laminarized when the rotation number approaches one. The characteristics of the flow field are investigated in both physical and spectral spaces, which include the analyses of the first- and second-order statistical moments, pre-multiplied spectra of velocity fluctuations, budget balance of the transport equation of Reynolds stresses, and coherent flow structures.

Download or read book Simulation of Turbulent Flows with and without Combustion with Emphasis on the Impact of Coherent Structures on the Turbulent Mixing written by Cunha Galeazzo, Flavio Cesar and published by KIT Scientific Publishing. This book was released on 2016-10-14 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: The analysis of turbulent mixing in complex turbulent flows is a challenging task. The effective mixing of entrained fluids to a molecular level is a vital part of the dynamics of turbulent flows, especially when combustion is involved. The work has shown the limitations of the steady-state simulations and acknowledged the need of applying high-fidelity unsteady methods for the calculation of flows with pronounced unsteadiness promoted by large-scale coherent structures or other sources.

Download or read book Direct Numerical Simulation of Two way Coupling Effects in a Particle laden Turbulent Pipe Flow written by Sarma L. Rani and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Direct Numerical Simulation of Compressible Turbulent Flows Using Adaptive Spectral Element Method written by T. J. Chung and published by . This book was released on 1994 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Direct Numerical Simulation of Transition to Turbulence and Turbulence Control in Pipe Flow written by and published by . This book was released on 2014 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subject of this thesis is the transition to turbulence and turbulence control in pipe flow. In pipes turbulence arises despite the linear stability of the laminar flow (subcritical transition) and directly from onset the flow is spatio-temporally complex. Given sufficiently strong perturbations, turbulence appears in localized patches (puffs) at low Reynolds numbers. At high Reynolds number, patches aggressively grow (slugs) and eventually render the flow fully turbulent. The questions of when and how turbulence starts to grow have long challenged scientists and will be discussed in-dep...

Download or read book Turbulent Flows written by Jean Piquet and published by Springer Science & Business Media. This book was released on 2001-03-26 with total page 778 pages. Available in PDF, EPUB and Kindle. Book excerpt: obtained are still severely limited to low Reynolds numbers (about only one decade better than direct numerical simulations), and the interpretation of such calculations for complex, curved geometries is still unclear. It is evident that a lot of work (and a very significant increase in available computing power) is required before such methods can be adopted in daily's engineering practice. I hope to l"Cport on all these topics in a near future. The book is divided into six chapters, each· chapter in subchapters, sections and subsections. The first part is introduced by Chapter 1 which summarizes the equations of fluid mechanies, it is developed in C~apters 2 to 4 devoted to the construction of turbulence models. What has been called "engineering methods" is considered in Chapter 2 where the Reynolds averaged equations al"C established and the closure problem studied (§1-3). A first detailed study of homogeneous turbulent flows follows (§4). It includes a review of available experimental data and their modeling. The eddy viscosity concept is analyzed in §5 with the l"Csulting ~alar-transport equation models such as the famous K-e model. Reynolds stl"Css models (Chapter 4) require a preliminary consideration of two-point turbulence concepts which are developed in Chapter 3 devoted to homogeneous turbulence. We review the two-point moments of velocity fields and their spectral transforms (§ 1), their general dynamics (§2) with the particular case of homogeneous, isotropie turbulence (§3) whel"C the so-called Kolmogorov's assumptions are discussed at length.