John H. Lienhard IV, John H. Lienhard V. A Heat Transfer Textbook, страница 2

. . . . . . . . . . . . . . . . . . . . . . . . . .5.2 Lumped-capacity solutions . . . . . . . . . . . . . . . . . . . .5.3 Transient conduction in a one-dimensional slab . . .5.4 Temperature-response charts . . . . . . . . . . . . . . . . . .5.5 One-term solutions . . . . . . . . . .

. . . . . . . . . . . . . . . .5.6 Transient heat conduction to a semi-infinite region .5.7 Steady multidimensional heat conduction . . . . . . . .5.8 Transient multidimensional heat conduction . . . . . .Problems . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . .References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Convective Heat Transfer139........................................141141143150159163183190193193194203208218220235247252265267Laminar and turbulent boundary layers2696.1 Some introductory ideas . . . .

. . . . . . . . . . . . . . . . . . . . . . 2696.2 Laminar incompressible boundary layer on a flat surface 2766.3 The energy equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2926.4 The Prandtl number and the boundary layer thicknesses 2966.5 Heat transfer coefficient for laminar, incompressible flowover a flat surface . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3006.6 The Reynolds analogy . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3116.7 Turbulent boundary layers . . . . . . . . . . . . . . . . . . . . . . . . 3136.8 Heat transfer in turbulent boundary layers . . . . . . . . . . . 322Problems . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 338Contents78Forced convection in a variety of configurations3417.1Introduction . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . .3417.2Heat transfer to and from laminar flows in pipes . . . . . .3427.3Turbulent pipe flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3557.4Heat transfer surface viewed as a heat exchanger . . . . . .3677.5Heat transfer coefficients for noncircular ducts . . . . . . . .3707.6Heat transfer during cross flow over cylinders . . . .

. . . . .3747.7Other configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . .384Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .386References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .393Natural convection in single-phase fluids and during filmcondensation3978.1Scope . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3978.2The nature of the problems of film condensation and ofnatural convection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .398Laminar natural convection on a vertical isothermalsurface . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . .4018.4Natural convection in other situations . . . . . . . . . . . . . . .4168.5Film condensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .428Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . .443References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4528.39ixHeat transfer in boiling and other phase-change configurations 4579.1Nukiyama’s experiment and the pool boiling curve . . . . .4579.2Nucleate boiling . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . .4649.3Peak pool boiling heat flux . . . . . . . . . . . . . . . . . . . . . . . .4729.4Film boiling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4869.5Minimum heat flux . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4889.6Transition boiling and system influences . . . . . . . .

. . . . .4899.7Forced convection boiling in tubes . . . . . . . . . . . . . . . . . .4969.8Forced convective condensation heat transfer . . . . . . . . .5059.9Dropwise condensation . . . . . . . . . . . . . . . . . . . . . . . . . . .5069.10 The heat pipe . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . .509Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .513References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .517ContentsxIVThermal Radiation Heat Transfer10 Radiative heat transfer10.1 The problem of radiative exchange . . . . . . . .

. . . . . . . . .10.2 Kirchhoff’s law . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10.3 Radiant heat exchange between two finite black bodies10.4 Heat transfer among gray bodies . . . . . . . . . . . . . . . . . .10.5 Gaseous radiation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10.6 Solar energy . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . .Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .VMass Transfer523........52552553353654956357458459259511 An introduction to mass transfer59711.1 Introduction . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 59711.2 Mixture compositions and species fluxes . . . . . . . . . . . . . 60011.3 Diffusion fluxes and Fick’s law . . . . . . . . . . . . . . . . . . . . . 60811.4 Transport properties of mixtures . . . . . . . . . . . . . . . . . . . 61411.5 The equation of species conservation . . . . . . .

. . . . . . . . . 62711.6 Mass transfer at low rates . . . . . . . . . . . . . . . . . . . . . . . . . 63511.7 Steady mass transfer with counterdiffusion . . . . . . . . . . . 64811.8 Mass transfer coefficients at high rates of mass transfer . 65411.9 Simultaneous heat and mass transfer . . . . . . . . . . . . . . . . 663Problems . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 673References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 686VIAppendices689A Some thermophysical properties of selected materials691References . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . 694BUnits and conversion factors721References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 722CNomenclature725Citation Index733Subject Index739Part IThe General Problem of HeatExchange11.IntroductionThe radiation of the sun in which the planet is incessantly plunged, penetrates the air, the earth, and the waters; its elements are divided, changedirection in every way, and, penetrating the mass of the globe, would raiseits temperature more and more, if the heat acquired were not exactlybalanced by that which escapes in rays from all points of the surface andexpands through the sky.The Analytical Theory of Heat, J.

Fourier1.1Heat transferPeople have always understood that something flows from hot objects tocold ones. We call that flow heat. In the eighteenth and early nineteenthcenturies, scientists imagined that all bodies contained an invisible fluidwhich they called caloric. Caloric was assigned a variety of properties,some of which proved to be inconsistent with nature (e.g., it had weightand it could not be created nor destroyed). But its most important featurewas that it flowed from hot bodies into cold ones. It was a very usefulway to think about heat. Later we shall explain the flow of heat in termsmore satisfactory to the modern ear; however, it will seldom be wrong toimagine caloric flowing from a hot body to a cold one.The flow of heat is all-pervasive.

It is active to some degree or anotherin everything. Heat flows constantly from your bloodstream to the airaround you. The warmed air buoys off your body to warm the room youare in. If you leave the room, some small buoyancy-driven (or convective)motion of the air will continue because the walls can never be perfectlyisothermal.

Such processes go on in all plant and animal life and in theair around us. They occur throughout the earth, which is hot at its coreand cooled around its surface. The only conceivable domain free fromheat flow would have to be isothermal and totally isolated from any otherregion.

It would be “dead” in the fullest sense of the word — devoid ofany process of any kind.3Introduction4§1.1The overall driving force for these heat flow processes is the cooling(or leveling) of the thermal gradients within our universe. The heat flowsthat result from the cooling of the sun are the primary processes that weexperience naturally. The conductive cooling of Earth’s center and the radiative cooling of the other stars are processes of secondary importancein our lives.The life forms on our planet have necessarily evolved to match themagnitude of these energy flows. But while “natural man” is in balancewith these heat flows, “technological man”1 has used his mind, his back,and his will to harness and control energy flows that are far more intensethan those we experience naturally.