Experimental laminar falling film heat transfer coefficients on a large diameter horizontal tube

摘要: A test rig was designed and fabricated to measure local heat transfer coefficients from a large-diameter, steam-heated horizontal tube thin falling films of water. The results the experiments generally support theory developed by Rogers for laminar film conditions, which were found persist up Reynolds numbers about 2000. Agreement between theoretical predictions measured values is reasonable thermal boundary layer development region, but are 20% lower than predicted in region. region attributed mainly thicknesses being greater values. Nous avons concu et fabrique une installation de forage experimental pour mesurer les transfert chaleur locaux d'un horizontal, chauffe la vapeur, gros diametre dans des d'eau minces descendants. Les resultats experiences confirmement en general theorie elaboree par conditions d'ecoulement laminaire, qui s'appliquent jusqu'a nombres du d'environ theoriques valeurs mesurees concordent raisonnablement bien developpement couche limite thermique, mais sont environ inferieures aux predites developpee. Ces developpee attribuees principalement epaisseurs se averees superieures predites.