SINGLE-PHASE PRESSURE DROP AND HEAT TRANSFER MEASUREMENTS OF TURBULENT FLOW INSIDE HELICALLY DIMPLED TUBES

2015 ◽  
Vol 22 (4) ◽  
pp. 345-363 ◽  
Author(s):  
Nae-Hyun Kim
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Turbulent Flow ◽  
Single Phase ◽  
Phase Pressure

SINGLE-PHASE HEAT TRANSFER AND PRESSURE DROP INSIDE INTERNALLY HELICAL-GROOVED HORIZONTAL SMALL-DIAMETER TUBES

2012 ◽  
Vol 20 (04) ◽  
pp. 1250022 ◽  
Author(s):  
NORIHIRO INOUE ◽  
JUNYA ICHINOSE
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Laminar Flow ◽  
Turbulent Flow ◽  
Single Phase ◽  
Small Diameter ◽  
Flow Region ◽  
Helix Angle ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients

An experimental study on pressure drop and heat transfer in single-phase was carried out using 10 types of internally helical-grooved and smooth small-diameter tubes with an outside diameter of 4 mm. The results are listed below: (1) In the turbulent flow region, fin height had the greatest effect, helix angle had only a minor effect, and the number of grooves had almost no effect upon the pressure drop versus the mass flow rate of the 4-mm grooved small-diameter tubes. In the laminar flow region, except for fin height, the shapes of the internal grooves had scarcely any effect upon pressure drop. (2) In the turbulent flow region, the heat transfer coefficients of the 4-mm grooved small-diameter tubes were greatly affected by fin height. The heat transfer coefficients became the maximum when a helix angle was near 15°, and there is a different tendency in the experiments of the pressure drop. On the other hand, there is almost no effect of the number of grooves. In the laminar flow region, there were no large differences in the heat transfer coefficients between the internally helical-grooved tubes and smooth small-diameter tube. (3) New empirical correlations for the friction factor and heat transfer coefficient in the laminar and turbulent flow regions were developed based on the experimental values. (4) The performance assessment in consideration of both heat transfer and pressure drop was indicated by using Colburn's analogy.

HEAT TRANSFER AND PRESSURE DROP IN TURBULENT FLOW THROUGH A TUBE WITH LONGITUDINAL PERFORATED STAR-SHAPED INSERTS

2011 ◽  
Vol 18 (6) ◽  
pp. 491-502 ◽  
Author(s):  
Andrew Mintu Sarkar ◽  
M. A. Rashid Sarkar ◽  
Mohammad Abdul Majid
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Turbulent Flow ◽  
Flow Through
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