Proposed Correlations for Laminar, Transition, and Turbulent Friction Factors in Micro-fin Tubes with Different Inlet Configurations

Abstract

Using the experimental data presented in Chap. 7, this chapter presents the developed accurate friction factor correlations for the laminar and transitional friction factors in the entrance and fully developed regions of micro-fin tubes under isothermal and non-isothermal (heating) conditions, different inlet configurations (square-edged and re-entrant), and different fin geometries (spiral angle, fin height-to-diameter ratio, and number of starts). For the fully developed turbulent region, the correlation of Jensen and Vlakancic (Int J Heat Mass Transfer 42:1343–1351, 1999) was recommended.KeywordsSingle-phase flowMicro-fin tubesFriction factor correlationsLaminar flowTransitional flowEntrance regionFully developed regionIsothermalNon-isothermalSquare-edged inletRe-entrant inletFin geometriesSpiral angleFin height-to-diameter ratioNumber of starts