## THERMAL SCIENCE

International Scientific Journal

### EXPERIMENTAL AND NUMERICAL ANALYSIS OF FORCED CONVECTION IN A TWISTED TUBE

**ABSTRACT**

In the present paper, along with experimental study, CFD analysis of forced convection in a twisted tube is performed, using the transition SST model which can predict the change of flow regime from laminar through transition to turbulent. The differential governing equations are discretized by the finite volume method. The investigations are conducted for Reynolds numbers ranging from 100 to 50000 covering laminar, transitional and turbulent regimes, and for three length and three pitch ratios. The predictions are observed to show a good agreement with the measurements and published correlations of other authors. The analysis indicates that the large length ratio and small pitch ratio yields a higher heat transfer rate with relatively low performance penalty. The transition from laminar to turbulent regime is observed between Reynolds numbers of 2500 to 3500 for all cases. For almost all investigated cases the performance factors are greater than unity.

**KEYWORDS**

PAPER SUBMITTED: 2018-11-21

PAPER REVISED: 2018-12-15

PAPER ACCEPTED: 2019-01-24

PUBLISHED ONLINE: 2019-09-22

**THERMAL SCIENCE** YEAR

**2019**, VOLUME

**23**, ISSUE

**Supplement 4**, PAGES [S1043 - S1052]

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