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A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Damage, sources of heat exchangers Damkohler number: Damping: Davis and Anderson criterion, for onset of nucleate boiling, Decal, heat transfer medium, Decane: 1-Decanol: 1-Decene: Degradation temperature, of polymers, Demisters, wire mesh, for multistage flash evaporators, Dengler and Addoms correlation, for forced convective heat transfer in two-phase flow, Density: Deposition of droplets in annular flow Deposition in fouling, Desalination plants: Desuperheaters for use in association with evaporators, Developing flow in ducts: Dew-poin corrosion, Diathermanous fluid, 1,1-Dibromoethane: Dibromomethane: 1,2-Dibromotetrafluoroethane (Refrigerant 114B2): Dibutylamine: Dibutyl ether: Dichloroacetic acid: o-Dichlorobenzene: Dichlorodifluoromethane (see Refrigerant 12) 1,1-Dichloroethane (Refrigerant 150a): 1,2-Dichloroethane (Refrigerant 150): 1,1-Dichloroethylene: cis-1,2-Dichloroethylene: trans-1,2-Dichloroethylene: Dichlorofluoromethane (see Refrigerant 21) Dichloromethane (Refrigerant 30): 1,2-Dichlorotetrafluoroethane (Refrigerant 114) 1,2,3-Dichlorotrifluoroethane (Refrigerant 123) Dielectric constant, of water, Diethylamine: n,n-Diethylaniline: Diethylene glycol: Diethyl ether: Diethyl ketone: Diethylsulfide: Differential condensation: Differential formulations for nonisothermal gas radiation, Differential resistance term in heat exchanger design, Differential vector operators in heat conduction, Diffraction models for radiative heat transfer from surfaces, Diffuse surfaces, radiative heat transfer between, Diffuse wall passages, radiative heat transfer in, Diffusers, single-phase flow and pressure drop in, Diffusion, in multi-component condensation, n,n-Diffusion coefficients: 1,1-Difluoroethane (Refrigerant 152a): Difluoromethane (Refrigerant 32): Diiodomethane: Diisobutylamine: Diisopropylamine: Diisopropylether: Dimensional analysis: Dimensionless groups: Dimethylacetylene: Dimethylamine: Dimethylaniline: 2,2-Dimethylbutane: 2,3-Dimethylbutane: 1,1-Dimethylcyclopentane: Dimethylether: Dimethylketone: 2,2-Dimethylpropane (neopentane): Dimethylsulfide: Dimpled surfaces, heat exchangers with, 1,4-Dioxane: Diphenyl: Diphenylamine: Diphenylether: Diphenylmethane: Dipropyl ether: Diisopropyl ether: Dipropyl ketone: Direct contact heat exchangers Direct contact heat transfer, Direct numerical simulation, of turbulence, Dirichlet boundary condition, finite difference method, Dished heads: Discretization in numerical analysis: Disk-and-doughnut baffled heat exchangers, Disks, free convective heat transfer from inclined, Dispersants, for fouling control, Dispersed flow (liquid-liquid), Dissipation of turbulent energy, Distillation: Distribution: Dittus-Boelter equation, for single-phase forced convective heat transfer, Dividing flow, loss coefficients in, Dodecane: 1-Dodecene: Donohue method, for shell-side heat transfer in shell-and-tube heat exchangers, Double-pipe heat exchangers: Double segmental baffled heat exchangers, Downward facing surfaces, free convective heat transfer from, Downward flow in vertical tubes, flow patterns in gas/liquid, Dowtherm A: Dowtherm J: Dowtherms, as heat transfer media, Drag coefficient: Drag force: Drag reduction, Drainage, of condensate, Dreitser, G, Drift flux model for two-phase flows, Drogemuller, P, Droplets: Dropwise condensation Dry wall desuperheating (in condensation), Dryers: Drying loft, Drying rates, prediction of, Dryout: Ducts, single-phase fluid flow and pressure drop in, Duplex stainless steels, Durand correlation for heterogeneous conveyance in solid/liquid flow, Dynamically stable foam, Dyphyl, heat transfer media, Dzyubenko, B,

Index

HEDH
A B C D
Damage, sources of heat exchangers Damkohler number: Damping: Davis and Anderson criterion, for onset of nucleate boiling, Decal, heat transfer medium, Decane: 1-Decanol: 1-Decene: Degradation temperature, of polymers, Demisters, wire mesh, for multistage flash evaporators, Dengler and Addoms correlation, for forced convective heat transfer in two-phase flow, Density: Deposition of droplets in annular flow Deposition in fouling, Desalination plants: Desuperheaters for use in association with evaporators, Developing flow in ducts: Dew-poin corrosion, Diathermanous fluid, 1,1-Dibromoethane: Dibromomethane: 1,2-Dibromotetrafluoroethane (Refrigerant 114B2): Dibutylamine: Dibutyl ether: Dichloroacetic acid: o-Dichlorobenzene: Dichlorodifluoromethane (see Refrigerant 12) 1,1-Dichloroethane (Refrigerant 150a): 1,2-Dichloroethane (Refrigerant 150): 1,1-Dichloroethylene: cis-1,2-Dichloroethylene: trans-1,2-Dichloroethylene: Dichlorofluoromethane (see Refrigerant 21) Dichloromethane (Refrigerant 30): 1,2-Dichlorotetrafluoroethane (Refrigerant 114) 1,2,3-Dichlorotrifluoroethane (Refrigerant 123) Dielectric constant, of water, Diethylamine: n,n-Diethylaniline: Diethylene glycol: Diethyl ether: Diethyl ketone: Diethylsulfide: Differential condensation: Differential formulations for nonisothermal gas radiation, Differential resistance term in heat exchanger design, Differential vector operators in heat conduction, Diffraction models for radiative heat transfer from surfaces, Diffuse surfaces, radiative heat transfer between, Diffuse wall passages, radiative heat transfer in, Diffusers, single-phase flow and pressure drop in, Diffusion, in multi-component condensation, n,n-Diffusion coefficients: 1,1-Difluoroethane (Refrigerant 152a): Difluoromethane (Refrigerant 32): Diiodomethane: Diisobutylamine: Diisopropylamine: Diisopropylether: Dimensional analysis: Dimensionless groups: Dimethylacetylene: Dimethylamine: Dimethylaniline: 2,2-Dimethylbutane: 2,3-Dimethylbutane: 1,1-Dimethylcyclopentane: Dimethylether: Dimethylketone: 2,2-Dimethylpropane (neopentane): Dimethylsulfide: Dimpled surfaces, heat exchangers with, 1,4-Dioxane: Diphenyl: Diphenylamine: Diphenylether: Diphenylmethane: Dipropyl ether: Diisopropyl ether: Dipropyl ketone: Direct contact heat exchangers Direct contact heat transfer, Direct numerical simulation, of turbulence, Dirichlet boundary condition, finite difference method, Dished heads: Discretization in numerical analysis: Disk-and-doughnut baffled heat exchangers, Disks, free convective heat transfer from inclined, Dispersants, for fouling control, Dispersed flow (liquid-liquid), Dissipation of turbulent energy, Distillation: Distribution: Dittus-Boelter equation, for single-phase forced convective heat transfer, Dividing flow, loss coefficients in, Dodecane: 1-Dodecene: Donohue method, for shell-side heat transfer in shell-and-tube heat exchangers, Double-pipe heat exchangers: Double segmental baffled heat exchangers, Downward facing surfaces, free convective heat transfer from, Downward flow in vertical tubes, flow patterns in gas/liquid, Dowtherm A: Dowtherm J: Dowtherms, as heat transfer media, Drag coefficient: Drag force: Drag reduction, Drainage, of condensate, Dreitser, G, Drift flux model for two-phase flows, Drogemuller, P, Droplets: Dropwise condensation Dry wall desuperheating (in condensation), Dryers: Drying loft, Drying rates, prediction of, Dryout: Ducts, single-phase fluid flow and pressure drop in, Duplex stainless steels, Durand correlation for heterogeneous conveyance in solid/liquid flow, Dynamically stable foam, Dyphyl, heat transfer media, Dzyubenko, B,
E F G H I J K L M N O P Q R S T U V W X Y Z

Vortex Heat Transfer Enhancement (VHTE)

DOI 10.1615/hedhme.a.000392

3.25.2 Vortex heat transfer enhancement (VHTE)

An example of the application of a "dimpled" surface is a surface of a golf ball that is covered by the pattern of spherical dimples. Early studies of the sphere aerodynamics of golf balls Bearman and Harvey (1976) indicated that they flew further and straighter when scored or marked. As shown in Figure 1, the drag force curve for the dimpled golf ball in the critical/supercritical flow regime differs remarkably from the corresponding curves for smooth and sand-roughened spheres; this results in a much further range than the smooth ball for the same initial conditions.

A wide range of studies have confirmed that flowing a gaseous medium over surfaces covered by spherical dimples can generate extremely stable vortices which provide very intensive mass and heat transfer between the dimpled surface and surrounding medium as illustrated in Figure 2a. The enhancement of heat transfer by this means will be referred to below as Vortex Heat Transfer Enhancement (VHTE).

In visualization experiments with the flat "dimpled" surfaces it was observed that columnar vortices generated by individual dimples at appropriate conditions are sucking the flow from the vicinity of the dimple and evacuating it in the core of the main flow stream. Moreover, those vortices actively interact with each other and create an oscillating flow pattern as shown in Figure 2b.

Figure 1 Variation of golf ball and sphere drag Bearman and Harvey (1976)

Figure 2 Basic mechanism of vortex formation in a dimple Afanasiev et al. (1993) and visualization of the flow over a dimpled surface Kiknadze et al. (2005) confirming the existence of the vortex

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