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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

A New Correlation for Single and Two-Phase Flow Pressure Drop in Round Tubes with Twisted-Tape Inserts

Kanizawa, Fabio T. [1] ; Hernandes, Renan S. [1] ; de Moraes, Anderson A. U. [1] ; Ribatski, Gherhardt [1]
Total Authors: 4
[1] Univ Sao Paulo, Escola Engn Sao Carlos, Dept Mech Engn, BR-13566590 Sao Carlos, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Journal of the Brazilian Society of Mechanical Sciences and Engineering; v. 33, n. SI, p. 243-250, JAN 2011.
Web of Science Citations: 9

Twisted-tape inserts are frequently used in heat exchangers as a passive and inexpensive heat transfer enhancement method. However, their use results not only heat transfer coefficient increments, but also pressure drop penalties. The present study analyses the literature on single and two-phase frictional pressure drop inside tubes with twisted-tape inserts focusing on the physical mechanism and the effects of the use of twisted-tape in comparison to plain tubes. Experimental data were gathered from the open literature and compared against the available correlations developed in order to predict two-phase frictional pressure drop in tubes containing twisted-tape inserts. It was found that none of the correlations was able to predict such a database accurately. A new correlation to estimate the friction factor for two-phase flows inside tubes with twisted-tape is also proposed. Contrarily to previous studies, the proposed correlation presents reasonable predictions under single and two-phase flow conditions and obeys the trends when the twisted-tape ratio tends to zero and infinite. (AU)

FAPESP's process: 08/10938-8 - Experimental evaluation of the thermal-hydraulic performance of R134a evaporation inside round tubes containing twisted-tape inserts
Grantee:Renan Sasahara Hernandes
Support type: Scholarships in Brazil - Scientific Initiation