Engineering Calculation Methods for Turbulent Flow by Peter Bradshaw, Tuncer Cebeci, James Whitelaw and a great selection of related books, art and collectibles available now at AbeBooks.com. Two pervasive themes that are not routinely familiar to turbulent-flow workers are the exploitation of balance equations for probability-density functions (rather than the more popular covariance and spectral functions) and, in variable-density problems, the use of density-weighted averages (‘ Favre averages ’) of the random field variables. Cebeci, T. and Khattab, A. A.: Prediction of turbulent-free-convective-heat transfer from a vertical flat plate. J. Heat Transfer 97:469 (1975). CrossRef Google Scholar Warner, C. Y. and Arpaci, V. S.: An experimental investigation of turbulent natural convection in air along a vertical heated flat plate. Int. J. Calculation of turbulent fluid flow in this paper is performed using a two-equation turbulent finite element model that can calculate values in the viscous sublayer. Methods: Implicit integration of the equations is used for determining the fluid velocity, turbulent kinetic energy and dissipation of turbulent kinetic energy. These values are ... 7. Basics of Turbulent Flow Whether a flow is laminar or turbulent depends of the relative importance of fluid friction (viscosity) and flow inertia. The ratio of inertial to viscous forces is the Reynolds number. Given the characteristic velocity scale, U, and length scale, L, for a system, the Reynolds Cebeci, T. ; Whitelaw, J. H. The use of partial differential equations to describe a wide range of flow conditions are examined. The emphasis is placed on conservation equations and the physical assumptions necessary to characterize turbulent flow and on numerical procedures for calculating the flow around airfoils and wings. Engineering Calculation Methods for Turbulent Flow by Peter Bradshaw, Tuncer Cebeci, James Whitelaw and a great selection of related books, art and collectibles available now at AbeBooks.com. Turbulence. In fluid dynamics, turbulence or turbulent flow is fluid motion characterized by chaotic changes in pressure and flow velocity. It is in contrast to a laminar flow, which occurs when a fluid flows in parallel layers, with no disruption between those layers. [1] Sections 13.4 and 13.5 described the numerical method and computer program used to obtain the boundary-layer flow results of Chapters 4 to 12. The following four sections of this chapter describe the steps required to obtain results for four new problems, in sufficient detail that a reader may reproduce earlier results for him- or herself and ... Turbulent secondary flows. Bradshaw, Peter. The development status of characterizations of conventional three-dimensional boundary layers and of the secondary flows with embedded streamwise vortices that are encountered in turbomachinery is evaluated. Attention is given to flows with strong skew-induced streamwise vorticity or dominated by ... Princeton University Library One Washington Road Princeton, NJ 08544-2098 USA (609) 258-1470 Engineering Calculation Methods for Turbulent Flow by Peter Bradshaw; Tuncer Cebeci; James H. Whitelaw and a great selection of related books, art and collectibles available now at AbeBooks.com. Practical Problems in Turbulent Reacting Flows (A. M. Mellor & C. R. 3. Turbulent Flows with Nonpremixed Reactants (R. W. Bilger); 4. Turbulent Flows with Premixed Reactants; 5. The Probability Density Function (pdf) Approach to Reacting Turbulent Flows 6. Perspective and Research Topics (P. A. Libby & F. A. Williams). and F. A. WILLIAMS. Engineering Calculation Methods for Turbulent Flow. Peter Bradshaw, Tuncer Cebeci, James H. Whitelaw. Academic Press, 1981 - Differential equations, Partial - 331 pages. ignored by authors of calculation methods and of review articles. As indicated by McDonald (Bertram 1969) integral calculation methods (solving ordinary differential equations for integral parameters) usually depend on the transformation of an incompressible-flow method, and stand or fall with the transformation. In turbulent flow the flow rate is proportional to the square root of the pressure gradient, as opposed to its direct proportionality to pressure gradient in laminar flow. Using the definition of the Reynolds number we can see that a large diameter with rapid flow, where the density of the blood is high, tends towards turbulence. Abstract. The main distinction between the treatment of turbulent flow in this chapter and Chapter 7 and the treatment of laminar flows in Chapters 4 and 5 is that whereas the diffusivities of momentum and heat are known transport properties in laminar flow, the effective diffusivities in turbulent flow are not. Engineering Calculation Methods for Turbulent Flow. Peter Bradshaw, Tuncer Cebeci, James H. Whitelaw. Academic Press, 1981 - Differential equations, Partial - 331 pages. Peter Bradshaw is the author of Physical and Computational Aspects of Convective Heat Transfer (5.00 avg rating, 5 ratings, 0 reviews, published 1984), S... Feb 2, 2011 · However, the turbulent flow develops only on the upset of stability of a laminar flow existing at Reynolds numbers below a certain critical value Re c, which is Re c = ūD/v = 2.3 × 10 3 for the tube flow. A developed turbulent flow is established in a tube, away from the inlet, when Re > 10 4, and in a boundary layer when Re x = u ∞ x/ν ... From the reviews: "The book has a broad and general coverage of both the mathematics and the numerical methods well suited for graduate students."Applied Mechanics Reviews #1 "This is a very well written book. Jan 1, 1981 · Engineering Calculation Methods for Turbulent Flow [Peter Bradshaw, Tuncer Cebeci, James Whitelaw] on Amazon.com. *FREE* shipping on qualifying offers. Engineering Calculation Methods for Turbulent Flow In this chapter we consider the finite-difference solution of the thin-shearlayer equations presented in previous chapters. In Section 13.1 we present a brief review of finite-difference techniques, discussing the relative advantages of implicit and explicit methods. As a result, the implicit Box scheme is preferred, and its use in internal and ... Engineering Calculation Methods for Turbulent Flow. Peter Bradshaw. 0.00. 0 ... Jan 1, 1988 · Fourteen modern calculation methods for three-dimensional turbulent boundary layers are described. The presentation is such that corresponding assumptions in the different methods can be directly compared. The results of applying these methods to common test cases are also available, but will be reported separately. Jan 1, 1982 · The purpose of this review is to describe and appraise components of calculation methods, based on the solution of conservation equations in differential form, for the velocity, temperature and concentration fields in turbulent combusting flows. Particular attention is devoted to the combustion models used within these methods and to gaseous ... Responsibility Peter Bradshaw, Tuncer Cebeci, James H. Whitelaw. Imprint London ; New York : Academic Press, 1981. Physical description xii, 331 p. : ill. ; 24 cm. What are you looking for Book "Engineering Calculation Methods For Turbulent Flows" ? Click "Read Now PDF" / "Download", Get it for FREE, Register 100% Easily. You can read all your books for as long as a month for FREE and will get the latest Books Notifications. SIGN UP NOW! Download and Read online engineering calculation methods for turbulent flow ebooks in PDF, epub, Tuebl Mobi, Kindle Book. Get Free engineering calculation methods for turbulent flow Textbook and unlimited access to our library by created an account. Cebeci, T. and Khattab, A. A.: Prediction of turbulent-free-convective-heat transfer from a vertical flat plate. J. Heat Transfer 97:469 (1975). CrossRef Google Scholar Warner, C. Y. and Arpaci, V. S.: An experimental investigation of turbulent natural convection in air along a vertical heated flat plate. Int. J. @misc{etde_6717609, title = {Engineering calculation methods for turbulent flow} author = {Bradshaw, P, Cebeci, T, and Whitelaw, J H} abstractNote = {The use of partial differential equations to describe a wide range of flow conditions are examined. The emphasis is placed on conservation equations and the physical assumptions necessary to ... Jul 4, 2016 · A Reynolds-stress model of turbulence and its application to thin shear flows. Journal of Fluid Mechanics, Vol 52, p. 609, 1972. Google Scholar. 49. Donaldson, C. duP. and Rosenbaum, H. Calculation of turbulent shear flows through closure of the Reynolds equations by invariant modelling. ARAP Inc Report 127, 1968. Turbulent secondary flows. Bradshaw, Peter. The development status of characterizations of conventional three-dimensional boundary layers and of the secondary flows with embedded streamwise vortices that are encountered in turbomachinery is evaluated. Attention is given to flows with strong skew-induced streamwise vorticity or dominated by ... Jan 1, 1982 · The purpose of this review is to describe and appraise components of calculation methods, based on the solution of conservation equations in differential form, for the velocity, temperature and concentration fields in turbulent combusting flows. Particular attention is devoted to the combustion models used within these methods and to gaseous ... Full text of "Engineering Calculation Methods For Turbulent Flow" See other formats ... Full text of "Engineering Calculation Methods For Turbulent Flow" See other formats ... Peter Bradshaw took his B.A. in Aeronautical Engineering at Cambridge University in 1957, and worked in the Aerodynamics Division of the National Physical Laboratory until 1969. He then joined the Department of Aeronautics, Imperial College, London University, where he was Professor of Experimental Aerodynamics until 1988. present volume on calculation methods included references 2, 5, 8, 9, and 12. Several review and background articles are also available (e.g. , refs. 13 to 25). All of these were quite valuable, especially the papers of Reynolds (refs. 19 and 20) and Bradshaw (ref. 22). Another category of general references is con- Engineering Calculation Methods for Turbulent Flow by Peter Bradshaw, Tuncer Cebeci, James Whitelaw and a great selection of related books, art and collectibles available now at AbeBooks.com. 26 Engineering Calculation Methods for Turbulent Flow 2 5 Averaged momentum equation With 0 = U + u,P = P + p and neglecting correlations with density fluctua tions the assumption that t/ = hm - - j &(x„X 2 ,X 3 ,l)dt ^1 “ h J(3 (t, - tj) are the mean and fluctuating parts of the scalar being considered, and r® is its diffusivity. The ... Mar 28, 2006 · The turbulent energy equation is converted into a differential equation for the turbulent shear stress by defining three empirical functions relating the turbulent intensity, diffusion and dissipation to the shear stress profile. This equation, the mean momentum equation and the mean continuity equation form a hyperbolic system. Download and Read online engineering calculation methods for turbulent flow ebooks in PDF, epub, Tuebl Mobi, Kindle Book. Get Free engineering calculation methods for turbulent flow Textbook and unlimited access to our library by created an account. Engineering Calculation Methods for Turbulent Flow by Peter Bradshaw, Tuncer Cebeci, James Whitelaw, May 01, 1981, Academic Press edition, Practical Problems in Turbulent Reacting Flows (A. M. Mellor & C. R. 3. Turbulent Flows with Nonpremixed Reactants (R. W. Bilger); 4. Turbulent Flows with Premixed Reactants; 5. The Probability Density Function (pdf) Approach to Reacting Turbulent Flows 6. Perspective and Research Topics (P. A. Libby & F. A. Williams). and F. A. WILLIAMS. Cebeci, T. ; Whitelaw, J. H. The use of partial differential equations to describe a wide range of flow conditions are examined. The emphasis is placed on conservation equations and the physical assumptions necessary to characterize turbulent flow and on numerical procedures for calculating the flow around airfoils and wings. Sections 13.4 and 13.5 described the numerical method and computer program used to obtain the boundary-layer flow results of Chapters 4 to 12. The following four sections of this chapter describe the steps required to obtain results for four new problems, in sufficient detail that a reader may reproduce earlier results for him- or herself and ... Turbulent secondary flows. Bradshaw, Peter. The development status of characterizations of conventional three-dimensional boundary layers and of the secondary flows with embedded streamwise vortices that are encountered in turbomachinery is evaluated. Attention is given to flows with strong skew-induced streamwise vorticity or dominated by ... Engineering Calculation Methods for Turbulent Flow by Bradshaw, Peter ; Tuncer Cebeci; James Whitelaw. Used; hardcover; Condition Very Good Plus/No Dust Jacket ISBN 10 0121245500 ISBN 13 9780121245504 Seller Aug 19, 2002 · Peter S. Bernard, PhD, is Professor of Mechanical Engineering at the University of Maryland. He is a fellow of the American Physical Society and serves as Chief Technology Officer of VorCat, Inc., a start-up company developing computer software for turbulent flow prediction based on his research in gridfree vortex methods. Practical Problems in Turbulent Reacting Flows (A. M. Mellor & C. R. 3. Turbulent Flows with Nonpremixed Reactants (R. W. Bilger); 4. Turbulent Flows with Premixed Reactants; 5. The Probability Density Function (pdf) Approach to Reacting Turbulent Flows 6. Perspective and Research Topics (P. A. Libby & F. A. Williams). and F. A. WILLIAMS. Engineering Calculation Methods for Turbulent Flow. Peter Bradshaw, Tuncer Cebeci, James H. Whitelaw. Academic Press, 1981 - Differential equations, Partial - 331 pages. present volume on calculation methods included references 2, 5, 8, 9, and 12. Several review and background articles are also available (e.g. , refs. 13 to 25). All of these were quite valuable, especially the papers of Reynolds (refs. 19 and 20) and Bradshaw (ref. 22). Another category of general references is con- @misc{etde_6717609, title = {Engineering calculation methods for turbulent flow} author = {Bradshaw, P, Cebeci, T, and Whitelaw, J H} abstractNote = {The use of partial differential equations to describe a wide range of flow conditions are examined. The emphasis is placed on conservation equations and the physical assumptions necessary to ... Practical Problems in Turbulent Reacting Flows (A. M. Mellor & C. R. 3. Turbulent Flows with Nonpremixed Reactants (R. W. Bilger); 4. Turbulent Flows with Premixed Reactants; 5. The Probability Density Function (pdf) Approach to Reacting Turbulent Flows 6. Perspective and Research Topics (P. A. Libby & F. A. Williams). and F. A. WILLIAMS. Engineering Calculation Methods for Turbulent Flow. Peter Bradshaw, Tuncer Cebeci, James H. Whitelaw. Academic Press, 1981 - Differential equations, Partial - 331 pages. present volume on calculation methods included references 2, 5, 8, 9, and 12. Several review and background articles are also available (e.g. , refs. 13 to 25). All of these were quite valuable, especially the papers of Reynolds (refs. 19 and 20) and Bradshaw (ref. 22). Another category of general references is con- What are you looking for Book "Engineering Calculation Methods For Turbulent Flows" ? Click "Read Now PDF" / "Download", Get it for FREE, Register 100% Easily. You can read all your books for as long as a month for FREE and will get the latest Books Notifications. SIGN UP NOW! Two pervasive themes that are not routinely familiar to turbulent-flow workers are the exploitation of balance equations for probability-density functions (rather than the more popular covariance and spectral functions) and, in variable-density problems, the use of density-weighted averages (‘ Favre averages ’) of the random field variables. EngineeringCalculationMethods forTurbulentFlow PETERBRADSHAW DepartmentofAeronautics ImperialCollegeofScienceandTechnology London TUNCERCEBECI ... Cebeci, T. ; Whitelaw, J. H. The use of partial differential equations to describe a wide range of flow conditions are examined. The emphasis is placed on conservation equations and the physical assumptions necessary to characterize turbulent flow and on numerical procedures for calculating the flow around airfoils and wings. We have 3 copies of Engineering Calculation Methods for Turbulent Flow for sale starting from $29.16. This website uses cookies. We value your privacy and use cookies to remember your shopping preferences and to analyze our website traffic. From the reviews: "The book has a broad and general coverage of both the mathematics and the numerical methods well suited for graduate students."Applied Mechanics Reviews #1 "This is a very well written book. 26 Engineering Calculation Methods for Turbulent Flow 2 5 Averaged momentum equation With 0 = U + u,P = P + p and neglecting correlations with density fluctua tions the assumption that t/ = hm - - j &(x„X 2 ,X 3 ,l)dt ^1 “ h J(3 (t, - tj) are the mean and fluctuating parts of the scalar being considered, and r® is its diffusivity. The ... Jan 1, 1982 · The purpose of this review is to describe and appraise components of calculation methods, based on the solution of conservation equations in differential form, for the velocity, temperature and concentration fields in turbulent combusting flows. Particular attention is devoted to the combustion models used within these methods and to gaseous ... Engineering Calculation Methods for Turbulent Flow by Peter Bradshaw, Tuncer Cebeci, James Whitelaw, May 01, 1981, Academic Press edition, What are you looking for Book "Engineering Calculation Methods For Turbulent Flows" ? Click "Read Now PDF" / "Download", Get it for FREE, Register 100% Easily. You can read all your books for as long as a month for FREE and will get the latest Books Notifications. SIGN UP NOW! Turbulent Flow and Transport 8 Introduction to Turbulence Models 8.1 Approaches to closure. Eddy diffusivity defined in terms of local turbulence intensit and length scale. 8.2 Equations for (i) the kinetic energy of the mean motion and for (ii) the mean kinetic energy associated with the turbulent fluctuations (the turbulence intensity k ... Title: An Introduction to Turbulence and Its Measurement Commonwealth and International Library. Thermodynamics and F Commonwealth and international library of science, technology, engineering and liberal studies: Thermodynamics and fluid mechanics division 7. Basics of Turbulent Flow Whether a flow is laminar or turbulent depends of the relative importance of fluid friction (viscosity) and flow inertia. The ratio of inertial to viscous forces is the Reynolds number. Given the characteristic velocity scale, U, and length scale, L, for a system, the Reynolds Cebeci, T. and Khattab, A. A.: Prediction of turbulent-free-convective-heat transfer from a vertical flat plate. J. Heat Transfer 97:469 (1975). CrossRef Google Scholar Warner, C. Y. and Arpaci, V. S.: An experimental investigation of turbulent natural convection in air along a vertical heated flat plate. Int. J. Abstract. The main distinction between the treatment of turbulent flow in this chapter and Chapter 7 and the treatment of laminar flows in Chapters 4 and 5 is that whereas the diffusivities of momentum and heat are known transport properties in laminar flow, the effective diffusivities in turbulent flow are not. A Dictionary of Quotes from the Saints (2001-02-01) PDF Download A Legacy of Kings...Israel's Chequered History (Search For Truth Series) PDF Kindle A Passion for Souls: The Life of D. L. Moody PDF Online Mar 28, 2006 · The turbulent energy equation is converted into a differential equation for the turbulent shear stress by defining three empirical functions relating the turbulent intensity, diffusion and dissipation to the shear stress profile. This equation, the mean momentum equation and the mean continuity equation form a hyperbolic system. Oct 19, 2020 · Mathematical models , Partial Differential equations , Turbulence. Showing 1 featured edition. View all 1 editions? Edition. Availability ↑. 1. Engineering calculation methods for turbulent flow. 1981, Academic Press. in English. Oct 19, 2020 · Mathematical models , Partial Differential equations , Turbulence. Showing 1 featured edition. View all 1 editions? Edition. Availability ↑. 1. Engineering calculation methods for turbulent flow. 1981, Academic Press. in English. Responsibility Peter Bradshaw, Tuncer Cebeci, James H. Whitelaw. Imprint London ; New York : Academic Press, 1981. Physical description xii, 331 p. : ill. ; 24 cm. Cebeci, T. and Khattab, A. A.: Prediction of turbulent-free-convective-heat transfer from a vertical flat plate. J. Heat Transfer 97:469 (1975). CrossRef Google Scholar Warner, C. Y. and Arpaci, V. S.: An experimental investigation of turbulent natural convection in air along a vertical heated flat plate. Int. J. 532.05101194 c739 computational methods for turbulent, transenic, and viscous flow: 532.0527 in8t turbulent shear flows 2: 532.0527 r631i interaction between dispersed particles and fluid turbulence in a flat-plate turbulent boundary layer in air Engineering Calculation Methods for Turbulent Flow by Bradshaw, Peter ; Tuncer Cebeci; James Whitelaw. Used; hardcover; Condition Very Good Plus/No Dust Jacket ISBN 10 0121245500 ISBN 13 9780121245504 Seller Engineering Calculation Methods for Turbulent Flow by Peter Bradshaw, Tuncer Cebeci, James Whitelaw and a great selection of related books, art and collectibles available now at AbeBooks.co.uk. Responsibility Peter Bradshaw, Tuncer Cebeci, James H. Whitelaw. Imprint London ; New York : Academic Press, 1981. Physical description xii, 331 p. : ill. ; 24 cm. Turbulent Flow and Transport 8 Introduction to Turbulence Models 8.1 Approaches to closure. Eddy diffusivity defined in terms of local turbulence intensit and length scale. 8.2 Equations for (i) the kinetic energy of the mean motion and for (ii) the mean kinetic energy associated with the turbulent fluctuations (the turbulence intensity k ... Engineering Calculation Methods for Turbulent Flow. Peter Bradshaw, Tuncer Cebeci, James H. Whitelaw. Academic Press, 1981 - Differential equations, Partial - 331 pages. Jan 1, 1981 · Engineering Calculation Methods for Turbulent Flow [Peter Bradshaw, Tuncer Cebeci, James Whitelaw] on Amazon.com. *FREE* shipping on qualifying offers. Engineering Calculation Methods for Turbulent Flow Feb 2, 2011 · However, the turbulent flow develops only on the upset of stability of a laminar flow existing at Reynolds numbers below a certain critical value Re c, which is Re c = ūD/v = 2.3 × 10 3 for the tube flow. A developed turbulent flow is established in a tube, away from the inlet, when Re > 10 4, and in a boundary layer when Re x = u ∞ x/ν ... Full text of "Engineering Calculation Methods For Turbulent Flow" See other formats ... Engineering Calculation Methods for Turbulent Flow by Peter Bradshaw; Tuncer Cebeci; James H. Whitelaw and a great selection of related books, art and collectibles available now at AbeBooks.com. Preface Manycalculationmethodshavebeendevelopedforturbulentflowsand theyprovideusefulinformationoverlimitedrangesofboundaryconditions. Correlationequations ...
Jan 1, 1981 · Engineering Calculation Methods for Turbulent Flow [Peter Bradshaw, Tuncer Cebeci, James Whitelaw] on Amazon.com. *FREE* shipping on qualifying offers. Engineering Calculation Methods for Turbulent Flow . Costcopercent27s enfield connecticut
Engineering Calculation Methods for Turbulent Flow by Peter Bradshaw, Tuncer Cebeci, James Whitelaw and a great selection of related books, art and collectibles available now at AbeBooks.co.uk. Peter Bradshaw is the author of Physical and Computational Aspects of Convective Heat Transfer (5.00 avg rating, 5 ratings, 0 reviews, published 1984), S... 26 Engineering Calculation Methods for Turbulent Flow 2 5 Averaged momentum equation With 0 = U + u,P = P + p and neglecting correlations with density fluctua tions the assumption that t/ = hm - - j &(x„X 2 ,X 3 ,l)dt ^1 “ h J(3 (t, - tj) are the mean and fluctuating parts of the scalar being considered, and r® is its diffusivity. The ... Jun 16, 2020 · Using a three-layer turbulence model for a cylindrical tube, an analytical calculation of the dissipation coefficient of the mechanical energy of flow in a smooth-walled cylindrical tube was performed, taking into account the turbulent viscosity. To take into account the turbulent viscosity, the turbulence model developed by Y. V. Lapin, O. A. Nekhamkin and M. Kh. Strelets was applied ... Practical Problems in Turbulent Reacting Flows (A. M. Mellor & C. R. 3. Turbulent Flows with Nonpremixed Reactants (R. W. Bilger); 4. Turbulent Flows with Premixed Reactants; 5. The Probability Density Function (pdf) Approach to Reacting Turbulent Flows 6. Perspective and Research Topics (P. A. Libby & F. A. Williams). and F. A. WILLIAMS. Nov 22, 2019 · Turbulent flows represent the non-stationary chaotic motion of liquid or gaseous media. Thus, it is impossible to give a strict mathematical description of the real picture of the turbulent flows. As a result, the virtual flow of the so-called quasi-stationary flow is realized. Download and Read online engineering calculation methods for turbulent flow ebooks in PDF, epub, Tuebl Mobi, Kindle Book. Get Free engineering calculation methods for turbulent flow Textbook and unlimited access to our library by created an account. Nov 22, 2019 · Turbulent flows represent the non-stationary chaotic motion of liquid or gaseous media. Thus, it is impossible to give a strict mathematical description of the real picture of the turbulent flows. As a result, the virtual flow of the so-called quasi-stationary flow is realized. In turbulent flow the flow rate is proportional to the square root of the pressure gradient, as opposed to its direct proportionality to pressure gradient in laminar flow. Using the definition of the Reynolds number we can see that a large diameter with rapid flow, where the density of the blood is high, tends towards turbulence. Practical Problems in Turbulent Reacting Flows (A. M. Mellor & C. R. 3. Turbulent Flows with Nonpremixed Reactants (R. W. Bilger); 4. Turbulent Flows with Premixed Reactants; 5. The Probability Density Function (pdf) Approach to Reacting Turbulent Flows 6. Perspective and Research Topics (P. A. Libby & F. A. Williams). and F. A. WILLIAMS. Jan 1, 1988 · Fourteen modern calculation methods for three-dimensional turbulent boundary layers are described. The presentation is such that corresponding assumptions in the different methods can be directly compared. The results of applying these methods to common test cases are also available, but will be reported separately. present volume on calculation methods included references 2, 5, 8, 9, and 12. Several review and background articles are also available (e.g. , refs. 13 to 25). All of these were quite valuable, especially the papers of Reynolds (refs. 19 and 20) and Bradshaw (ref. 22). Another category of general references is con- .