Developing Flow and Heat Transfer in Strongly Curved Ducts of Rectangular Cross-section PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Developing Flow and Heat Transfer in Strongly Curved Ducts of Rectangular Cross-section PDF full book. Access full book title Developing Flow and Heat Transfer in Strongly Curved Ducts of Rectangular Cross-section by . Download full books in PDF and EPUB format.
Author: Publisher: ISBN: Category : Languages : en Pages :
Book Description
A numerical study of heat transfer in 90°, constant cross-section curved duct, steady, laminar flow is presented. The work is aimed primarily at characterizing the effects of duct geometry on heat transfer by considering, especially, the role of secondary motions during the developing period of the flow. However, due consideration has also been given to varying initial conditions of velocity and temperature at the entrance section to the duct. In addition, an assessment is made of the relative contributions of individual duct walls to heat transfer in the flow. It is found that, in general, heat transfer increases with Dean number with the largest transfer rates occurring through the duct side walls and outer-curvature wall. Duct geometries with aspect ratio greater or smaller than unity have weaker secondary motions and are less effective for heat transfer. Similarly, plug-flow entrance profiles for velocity retard the development of cross-section flow thus inhibiting a significant contribution to heat transfer. It is concluded that short ducts with strong curvature and intense secondary motions can be as effective for heat transfer as longer ducts which are less strongly curved. Calcuations are based on fully elliptic (in space) forms of the transport equation governing the flow. They are of engineering value and are limited in accuracy only by the degree of computational mesh refinement. A comparison with calculations based on parabolic equations has been made and it is shown how the latter can lead to erroneous results for strongly curved flows.
Author: Publisher: ISBN: Category : Languages : en Pages :
Book Description
A numerical study of heat transfer in 90°, constant cross-section curved duct, steady, laminar flow is presented. The work is aimed primarily at characterizing the effects of duct geometry on heat transfer by considering, especially, the role of secondary motions during the developing period of the flow. However, due consideration has also been given to varying initial conditions of velocity and temperature at the entrance section to the duct. In addition, an assessment is made of the relative contributions of individual duct walls to heat transfer in the flow. It is found that, in general, heat transfer increases with Dean number with the largest transfer rates occurring through the duct side walls and outer-curvature wall. Duct geometries with aspect ratio greater or smaller than unity have weaker secondary motions and are less effective for heat transfer. Similarly, plug-flow entrance profiles for velocity retard the development of cross-section flow thus inhibiting a significant contribution to heat transfer. It is concluded that short ducts with strong curvature and intense secondary motions can be as effective for heat transfer as longer ducts which are less strongly curved. Calcuations are based on fully elliptic (in space) forms of the transport equation governing the flow. They are of engineering value and are limited in accuracy only by the degree of computational mesh refinement. A comparison with calculations based on parabolic equations has been made and it is shown how the latter can lead to erroneous results for strongly curved flows.
Author: R. C. Buggeln Publisher: ISBN: Category : Laminar flow Languages : en Pages : 84
Book Description
Both laminar and turbulent flows in strongly curved ducts, channels, and pipes are studied by numerical methods. The study concentrates on the curved square-duct geometry and flow conditions for which detailed measurements have been obtained recently by Taylor, Whitelaw, and Yianneskis. The solution methodology encompasses solution of the compressible ensemble-averaged Navier-Stokes equations at low Mach number using a split linearized block implicit (LBI) scheme, and rapid convergence on the order of 80 noniterative time steps is obtained. The treatment of turbulent flows includes resolution of the viscous sublayer region. A series of solutions for both laminar and turbulent flow and for both two- and three-dimensional geometries of the same curvature are presented. The accuracy of these solutions is explored by mesh refinement and by comparison with experiment. In summary, good qualitative and reasonable quantitative agreement between solution and experiment is obtained. Collectively, this sequence of results serves to clarify the physical structure of these flows and hence how grid selection procedures might be adjusted to improve the numerical accuracy and experimental agreement. For a three-dimensional flow of considerable complexity, the relatively good agreement with experiment obtained for the turbulent flow case despite a coarse grid must be regarded as encouraging. (Author).
Author: Rainer Friedrich Publisher: Springer Science & Business Media ISBN: 1402023138 Category : Science Languages : en Pages : 652
Book Description
The fifth ERCOFfAC workshop 'Direct and Large-Eddy Simulation-5' (DLES-5) was held at the Munich University of Technology, August 27-29, 2003. It is part of a series of workshops that originated at the University of Surrey in 1994 with the intention to provide a forum for presentation and dis cussion of recent developments in the field of direct and large-eddy simula tion. Over the years the DLES-series has grown into a major international venue focussed on all aspects of DNS and LES, but also on hybrid methods like RANSILES coupling and detached-eddy simulation designed to provide reliable answers to technical flow problems at reasonable computational cost. DLES-5 was attended by 111 delegates from 15 countries. Its three-day pro gramme covered ten invited lectures and 63 original contributions partially pre sented in parallel sessions. The workshop was financially supported by the fol lowing companies, institutions and organizations: ANSYS Germany GmbH, AUDI AG, BMW Group, ERCOFfAC, FORTVER (Bavarian Research Asso ciation on Combustion), JM BURGERS CENTRE for Fluid Dynamics. Their help is gratefully acknowledged. The present Proceedings contain the written versions of nine invited lectures and fifty-nine selected and reviewed contributions which are organized in four parts: 1 Issues in LES modelling and numerics 2 Laminar-turbulent transition 3 Turbulent flows involving complex physical phenomena 4 Turbulent flows in complex geometries and in technical applications.
Author: James Claude Ballard (III.) Publisher: ISBN: Category : Languages : en Pages : 72
Book Description
Experimental investigations have been conducted to examine the general problem of convective heat transfer in a rectangular cross section channel with both straight and curved passages. The experimental configuration was modeled as infinite parallel plates with one wall at a constant heat flux and the opposite wall adiabatic. The air flow through the channel was heated through the Joulean heating of a wall composed of Temsheet. Liquid crystals applied to the surface of the Temsheet were used to confirm the presence of the Taylor-Gortler vortices. Average Nusselt number mesurements were used to investigate their effect on heat transfer from the curved test section. Experiments were conducted for steady state laminar flow that was hydrodynamically developed and thermally developing. It was confirmed that the Taylor-Gortler vortices enhanced the heat transfer process in the curved section. The experimental data was compared with several analytic studies with good results. (Author).
Author: Publisher: ISBN: Category : Power resources Languages : en Pages : 1430
Book Description
Semiannual, with semiannual and annual indexes. References to all scientific and technical literature coming from DOE, its laboratories, energy centers, and contractors. Includes all works deriving from DOE, other related government-sponsored information, and foreign nonnuclear information. Arranged under 39 categories, e.g., Biomedical sciences, basic studies; Biomedical sciences, applied studies; Health and safety; and Fusion energy. Entry gives bibliographical information and abstract. Corporate, author, subject, report number indexes.
Author: Robert George Holihan (Jr) Publisher: ISBN: Category : Languages : en Pages : 81
Book Description
An experimental investigation was conducted to examine convection heat transfer in a duct of rectangular cross-section, having both a straight and curved flow passage. One wall was kept at a constant temperature, with the opposite wall being adiabatic. Heating of the air flowing in the channel was accomplished through Joulean heating of a wall composed of Temsheet. The experiments were conducted for steady state in Laminar and Transition flows. Development and propagation of the Taylor-Gortler vortices was shown to enhance the heat transfer rate in the curved section as compared to the straight section. (Author).
Author: 
Author: 
Author: R. C. Buggeln
Author: Rainer Friedrich
Author: James Claude Ballard (III.)
Author: 
Author: J. P. Kreskovsky
Author: Sadik Kakaç
Author: Robert George Holihan (Jr)
Author: Gregory Martin Chrysler
Author: R. K. Shah