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Heat Transfer Handbook part 108. The Heat Transfer Handbook provides succinct hard data, formulas, and specifications for the critical aspects of heat transfer, offering a reliable, hands-on resource for solving day-to-day issues across a variety of applications. | EXTENDED SURFACES 1067 where each geometric variable is identified in Fig. 14.20. These equations quite accurately represent the experimental data continuously in the laminar transition and turbulent flow regimes Manglik and Bergles 1995 . For tube fin heat exchangers Wang 2000 has given a comprehensive review of 51 patents issued in the period 1981-1991 for a variety of louvered- wavy- and slit fin and punched tab protruded-tab vortex generators fin surfaces. Wang et al. 2001 have also provided an extended review and compilation of correlations for plain wavy louvered and slit fins. The applicability of these predictive equations to both dry and wet dehumidifying conditions has been discussed along with the issue of hydrophilic coatings. For the wavy fin tube fin coil a numerical simulation for the air-side performance has been reported by Min and Webb 2001 . Metwally and Manglik 2000 have analyzed periodically developed laminar forced convection in wavy plate fin cores. Their numerical model considers two-dimensional sinusoidal-wavy plate fins which is applicable when the fin height fin spacing and the results depicted in Fig. 14.21 show a strong influence of the wall waviness on the enhanced performance represented by the area goodness factor j f the development and applicability of this figure of merit for compact heat exchangers are outlined in Shah and London 1978 . Subsequent work on three-dimensional wavy plate fin channels finite fin height shows trends that are similar albeit different in magnitude Muley et al. 2002 Zhang et al. 2002 . 14.4.2 Boiling Internally finned tubes are commonly in refrigerant evaporators as well as some other applications for flow boiling. A variety of different geometries are used and some typical cases made up of large medium or low and microfin heights are shown in Fig. 14.22. As pointed out by Bergles 2000 increases in the average heat transfer coefficient of up to 200 based on the smooth or empty tube of the same diameter .
