Frictional pressure drop correlations for single-phase flow, condensation and evaporation in microfin tubes
Författare
Summary, in English
Experimental single-phase, condensation, and evaporation (flow boiling) pressure drop data from the literature and our previous studies were collected to evaluate previous frictional pressure drop correlations for horizontal microfin tubes of different geometries. The modified Ravigururajan and Bergles correlation, by adopting the Churchill model to calculate the smooth-tube friction factor and by using the hydraulic diameter in the Reynolds number, can predict single-phase turbulent frictional pressure drop data relatively well. Eleven pressure drop correlations were evaluated by the collected database for condensation and evaporation. Correlations originally developed for condensation and evaporation in smooth tubes can be suitable for microfin tubes if the friction factors in the correlations were calculated by the Churchill model to include microfin effects. The three most accurate correlations were recommended for condensation and evaporation in microfin tubes. The Cavallini et al. correlation and the modified Friedel correlation can give good predictions for both condensation and evaporation. However, some inconsistencies were found, even for the recommended correlations.
Publiceringsår
2015
Språk
Engelska
Sidor
1-022901
Publikation/Tidskrift/Serie
Journal of Heat Transfer
Volym
138
Issue
2
Dokumenttyp
Artikel i tidskrift
Förlag
American Society Of Mechanical Engineers (ASME)
Ämne
- Energy Engineering
Status
Published
Forskningsgrupp
- heat transfer
ISBN/ISSN/Övrigt
- ISSN: 0022-1481