Allan D. Kraus

Extended Surface Heat Transfer

Preface. Convection with Simplified Constraints. Convection with Real Constraints. Convective Optimizations. Convection Coefficients. Linear Transformations. Elements of Linear Transformations. Algorithms for Finned Array Assembly. Advanced Array Methods and Array Optimization. Finned Passages. Compact Heat Exchangers. Longitudinal Fin Double-Pipe Exchangers. Transverse High-Fin Exchangers. Fins with Radiation. Optimum Design of Radiating and Convecting-Radiating Fins. Multidimensional Heat Transfer in Fins and Fin Assemblies. Transient Heat Transfer in Extended Surfaces. Periodic Heat Flow in Fins. Boiling From Finned Surfaces. Condensation on Finned Surfaces. Augmentation and Additional Studies. Appendix A: Gamma and Bessel Functions. Appendix B: Matrices and Determinants. References. Author Index. Subject Index.

Sixty-Five Years of Extended Surface Technology (1922–1987)

The extended surface literature from 1922 to 1987 is reviewed. The review begins with the classic NACA report of Harper and Brown published in 1922 and concludes with the works of Marto, Wanniarachchi, Rose, Mitrou, and Razelos published in 1986. A section entitled “The Beginnings” traces the accomplishments of the pioneers and it covers the period from 1922 to 1945 which coincides with the publication of Gardner’s landmark paper. At this point, a chronological approach is abandoned in favor of a categorization into topical areas. These are the elimination of the Murray–Gardner assumptions, boiling and condensation, experimental endeavors, compact heat exchangers, internally finned configurations, numerical analyses, optimizations, analyses of finned arrays, and additional topics including the use of extended surface to augment heat transfer, heat transfer in electrical and electronic equipment, purely mathematical techniques, and heat and mass transfer.

Transient Heat Transfer in Extended Surfaces

This paper attempts to provide a comprehensive, coherent, and methodical review of the existing literature on the transient performance of extended surfaces (fins). With the exception of very few experimental studies, the work described is theoretical involving either analytical approaches or numerical computations. For both longitudinal and radial convecting fins, the shapes analyzed include fins of rectangular, trapezoidal, concave parabolic, and convex parabolic profiles. The boundary conditions considered are those of time-dependent base temperature or time-dependent base heat flow, or time-dependent temperature of the fluid on the unfinned side of the primary surface. Other studies discussed consider the transient responses of radiating and convecting-radiating fins, fins with stochastic base temperature and fins in which conduction, natural convection, and radiation are coupled. The paper also provides an in-depth consideration of two-dimensional analyses of a cylindrical spine (pin fin) and a composite longitudinal fin. All of the important results pertaining to the transient effect in extended surfaces are presented and these effects are illustrated with several examples. The paper concludes with an attempt to identify future investigative efforts.