scholarly journals Heat transfer and pressure drop in the transitional flow regime for a smooth circular tube with twisted tape inserts and a square-edged inlet

2018 ◽  
Vol 117 ◽  
pp. 11-29 ◽  
Author(s):  
J.P. Meyer ◽  
S.M. Abolarin
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Flow Regime ◽  
Circular Tube ◽  
Transitional Flow ◽  
Twisted Tape

Enhancement and Prediction of Heat Transfer Rate in Turbulent Flow Through Tube With Perforated Twisted Tape Inserts: A New Correlation

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
J. U. Ahamed ◽  
M. A. Wazed ◽  
S. Ahmed ◽  
Y. Nukman ◽  
T. M. Y. S. Tuan Ya ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Turbulent Flow ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Circular Tube ◽  
Twisted Tape ◽  
Pumping Power ◽  
Plain Tube ◽  
Flow Through

An experimental investigation has been carried out for turbulent flow in a tube with perforated twisted tape inserts. The mild steel twisted tape inserts with circular holes of different diameters (i.e., perforation) are used in the flow field. An intensive laboratory study is conducted for heat transfer and pressure drop characteristics in the tubes for turbulent flow with various airflow rates. Heat transfer and pressure drop data are engendered for a wide range Reynolds number (1.3×104–5.2×104). Tube wall temperature, pressure drop, air velocity, and its temperature are measured both for plain tube and for tube with perforated twisted tape inserts. Heat transfer coefficients, Nusselt number, pumping power, and heat transfer effectiveness are calculated for both cases. Experimental results showed that perforated twisted inserts of different geometry in a circular tube enhanced the heat transfer rate with an increase in friction factor and pumping power for turbulent flow. The pumping power, heat transfer coefficient, and effectiveness in the tube with the twisted tape inserts are found to increase up to 1.8, 5.5, and 4.0 times of those for the plain tube for same Reynolds number, respectively. Finally, a correlation is developed for prediction of the heat transfer rate for turbulent flow through a circular tube with perforated twisted tape inserts.

Heat Transfer and Pressure Drop Characteristics of Water in the Transitional Flow Regime of Horizontal Smooth Tubes at Constant Wall Temperature

2010 ◽  
Author(s):  
J. P. Meyer ◽  
A. Du Preez
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Flow Regime ◽  
Wall Temperature ◽  
Reynolds Numbers ◽  
Transitional Flow ◽  
Maximum Efficiency ◽  
Constant Wall Temperature ◽  
Pressure Losses ◽  
Nusselt Numbers

Owing to design limitations, heat exchangers are frequently forced to operate in the transitional flow regime, however, there exists no accurate measurements for both heat transfer and pressure drop in this region. In order to optimize a heat exchanger for maximum efficiency and minimum pressure losses, it is required to design it for the transitional flow regime. Therefore, the purpose of this study is to obtain accurate Nusselt numbers and pressure drop coefficients for water flowing through a horizontal smooth tube with a constant wall temperature. Heat transfer and pressure drop measurements were conducted on a 5.33 mm tube at Reynolds numbers ranging from 1 000 to 5 000.

Sign in / Sign up

Export Citation Format

Share Document