A Direct Numerical Simulation of Fully Developed Turbulent Channel Flow with Passive Heat Transfer

A Direct Numerical Simulation of Fully Developed Turbulent Channel Flow with Passive Heat Transfer
Author: Stephen Lincoln Lyons
Publisher:
Total Pages: 670
Release: 1989
Genre: Heat
ISBN:
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A direct numerical simulation of a fully developed turbulent channel flow with passive heat transfer is performed. The time-dependent three-dimensional Navier-Stokes equations and advection-diffusion equation are solved numerically using a pseudospectral technique with 1,064,960 grid points in physical space (128 x 65 x 128 in x, y, z). No subgrid scale model is employed since all essential turbulence scales are resolved. The Reynolds number is 2262, based on the half channel height and bulk velocity, and the Prandtl number is 1. The Nusselt number is predicted to be 25.36. A large number of one-point turbulence statistics are computed and compared with existing experimental data taken at similar Reynolds and Nusselt numbers. Agreement with the existing experimental data is excellent except for some discrepancies in the near wall region, y$sp+$ $

Turbulent Shear Flows 8

Turbulent Shear Flows 8
Author: Franz Durst
Publisher: Springer Science & Business Media
Total Pages: 419
Release: 2012-12-06
Genre: Science
ISBN: 3642776744
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This volume contains a selection of the papers presented at the Eighth Symposium on Turbulent Shear Flows held at the Technical University of Munich, 9-11 September 1991. The first of these biennial international symposia was held at the Pennsylvania State Uni versity, USA, in 1977; subsequent symposia have been held at Imperial College, London, England; the University of California, Davis, USA; the University of Karlsruhe, Ger many; Cornell University, Ithaca, USA; the Paul Sabatier University, Toulouse, France; and Stanford University, California, USA. The purpose of this series of symposia is to provide a forum for the presentation and discussion of new developments in the field of turbulence, especially as related to shear flows of importance in engineering and geo physics. From the 330 extended abstracts submitted for this symposium, 145 papers were presented orally and 60 as posters. Out of these, we have selected twenty-four papers for inclusion in this volume, each of which has been revised and extended in accordance with the editors' recommendations. The following four theme areas were selected after consideration of the quality of the contributions, the importance of the area, and the selection made in earlier volumes: - wall flows, - separated flows, - compressibility effects, - buoyancy, rotation, and curvature effects. As in the past, each section corresponding to the above areas begins with an introduction by an authority in the field that places the individual contributions in context with one another and with related research.

Large Eddy Simulation of Compressible Turbulent Pipe Flow with Heat Transfer

Large Eddy Simulation of Compressible Turbulent Pipe Flow with Heat Transfer
Author: Xiaofeng Xu
Publisher:
Total Pages: 306
Release: 2003
Genre:
ISBN:
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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.

Direct Numerical Simulation of Turbulent Flow and Heat Transfer in a Square Duct at Low Reynolds Number

Direct Numerical Simulation of Turbulent Flow and Heat Transfer in a Square Duct at Low Reynolds Number
Author: M. Piller
Publisher:
Total Pages: 8
Release: 2001
Genre:
ISBN:
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In this paper, we present the results from Direct Numerical Simulations of turbulent, incompressible flow through a square duct, with an imposed temperature difference between two opposite walls, while the other two walls are assumed perfectly insulated. The mean flow is sustained by an imposed, mean pressure gradient. The most interesting feature, characterizing this geometry, consists in the presence of turbulence-sustained mean secondary motions in the cross-flow plane. In this study, we focus on weak turbulence, in that the Reynolds number, based on bulk velocity and hydraulic diameter, is about 4450. Our results indicate that secondary motions do not affect dramatically the global parameters, like friction factor and Nusselt number, in comparison with the plane-channel flow. This issue is investigated by looking at the distribution of the various contributions to the total heat flux, with particular attention to the mean convective term, which does not appear in the plane channel flow.

Direct Numerical Simulation of Turbulent Flow and Heat Transfer in a Concentric Annular Pipe

Direct Numerical Simulation of Turbulent Flow and Heat Transfer in a Concentric Annular Pipe
Author: Edris Bagheri
Publisher:
Total Pages: 0
Release: 2021
Genre:
ISBN:
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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.

Engineering Turbulence Modelling and Experiments 5

Engineering Turbulence Modelling and Experiments 5
Author: W. Rodi
Publisher: Elsevier
Total Pages: 1029
Release: 2002-08-21
Genre: Mathematics
ISBN: 008053094X
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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.

Convective Heat and Mass Transfer

Convective Heat and Mass Transfer
Author: S. Mostafa Ghiaasiaan
Publisher: CRC Press
Total Pages: 788
Release: 2018-06-12
Genre: Science
ISBN: 1351112732
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Convective Heat and Mass Transfer, Second Edition, is ideal for the graduate level study of convection heat and mass transfer, with coverage of well-established theory and practice as well as trending topics, such as nanoscale heat transfer and CFD. It is appropriate for both Mechanical and Chemical Engineering courses/modules.

Spectral Methods in Fluid Dynamics

Spectral Methods in Fluid Dynamics
Author: Claudio Canuto
Publisher: Springer Science & Business Media
Total Pages: 582
Release: 2012-12-06
Genre: Science
ISBN: 3642841082
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This is a book about spectral methods for partial differential equations: when to use them, how to implement them, and what can be learned from their of spectral methods has evolved rigorous theory. The computational side vigorously since the early 1970s, especially in computationally intensive of the more spectacular applications are applications in fluid dynamics. Some of the power of these discussed here, first in general terms as examples of the methods have been methods and later in great detail after the specifics covered. This book pays special attention to those algorithmic details which are essential to successful implementation of spectral methods. The focus is on algorithms for fluid dynamical problems in transition, turbulence, and aero dynamics. This book does not address specific applications in meteorology, partly because of the lack of experience of the authors in this field and partly because of the coverage provided by Haltiner and Williams (1980). The success of spectral methods in practical computations has led to an increasing interest in their theoretical aspects, especially since the mid-1970s. Although the theory does not yet cover the complete spectrum of applications, the analytical techniques which have been developed in recent years have facilitated the examination of an increasing number of problems of practical interest. In this book we present a unified theory of the mathematical analysis of spectral methods and apply it to many of the algorithms in current use.