scholarly journals Analysis and Implementation of Thermal Heat Exchanger Tube Performance with Helically Pierced Twisted Tape Inserts Using ANFIS Model

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Faisal Altarazi ◽  
Sunil Kumar ◽  
Gaurav Gupta ◽  
Muhammad Gulzar ◽  
Yaé Ulrich Gaba ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
System Modeling ◽  
Diameter Ratio ◽  
Twisted Tape ◽  
Heat Exchanger Tube ◽  
Anfis Model ◽  
Inference System ◽  
Relative Pitch ◽  
Pitch Ratio ◽  
Exchanger Tube

The present work used ANFIS, an adaptive neuro-fuzzy inference system modeling to analyze the effect of the variable parameters of helically pierced twisted tape inserts on the Nusselt number, friction factor, and thermo-hydraulic heat exchanger tube performance. The experimental data utilized for ANFIS modeling considered a diameter ratio ranging from 0.57 to 0.80, a relative pitch ratio ranging from 0.046 to 0.107, a perforation index ranging from 5% to 20% as variable twisted tape parameters and flow parameters. The Reynolds number varies from 4000 to 30000. The analysis showed that the maximum thermo-hydraulic performance was obtained at a diameter ratio of 0.65, a relative pitch ratio of 0.085, and a perforation index equal to 10%. The result predicts that the ANFIS model and experimental results are in good agreement as they have only ±0.53% deviations.

Sensitivity Analysis of a Heat Exchanger Tube Fitted With Cross-Cut Twisted Tape With Alternate Axis

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
M. E. Nakhchi ◽  
J. A. Esfahani
Keyword(s):  
Heat Transfer ◽  
Sensitivity Analysis ◽  
Reynolds Number ◽  
Heat Exchanger ◽  
Thermal Performance ◽  
Diameter Ratio ◽  
Design Parameters ◽  
Twisted Tape ◽  
Heat Exchanger Tube ◽  
Exchanger Tube

Numerical simulations are used to analyze the thermal performance of turbulent flow inside heat exchanger tube fitted with cross-cut twisted tape with alternate axis (CCTA). The design parameters include the Reynolds number (5000<Re<15,000), cross-cut width ratio (0.7<b/D<0.9), cross-cut length ratio (2<s/D<2.5), and twist ratio (2<y/D<4). The objective functions are the Nusselt number ratio (Nu/Nus), the friction factor ratio (f/fs), and the thermal performance (η). Response surface method (RSM) is used to construct second-order polynomial correlations as functions of design parameters. The regression analysis shows that heat transfer ratio decreased with increasing both the Reynolds number and the width to diameter ratio of the twisted tape. This means that the twisted tape has more influence on heat transfer at smaller inlet fluid velocities. Sensitivity analysis reveals that among the effective input parameters, the sensitivity of Nu/Nus to the Reynolds number is the highest. The results reveal that thermal performance enhances with increasing the width to diameter ratio of the twisted tape (b/D). The maximum thermal performance factor of 1.531 is obtained for the case of Re=5000, b/D=0.9, s/D=2.5, and y/D=4.

Spanwise Correlation of Surface Pressure Fluctuations in Heat Exchanger Tube Arrays

2010 ◽  
Author(s):  
John Mahon ◽  
Paul Cheeran ◽  
Craig Meskell
Keyword(s):  
Heat Exchanger ◽  
Surface Pressure ◽  
Pressure Fluctuations ◽  
Cross Flow ◽  
Fretting Wear ◽  
Heat Exchanger Tube ◽  
Tube Arrays ◽  
Pitch Ratio ◽  
Excitation Mechanisms ◽  
Exchanger Tube

An experimental study of the surface spanwise pressure on a cylinder in the third row of two normal triangular tube arrays (P/d = 1.32 and 1.58) with air cross flow has been conducted. A range of flow velocities were examined. The correlation of surface pressure fluctuations due to various vibration excitation mechanisms along the span of heat exchanger tubes has been assessed. The turbulent buffeting is found to be uncorrelated along the span which is consistent with generally accepted assumptions in previous studies. Vortex shedding and acoustic resonances were well correlated along the span of the cylinder, with correlations lengths approaching the entire length of the cylinder. Jet switching was observed in the pitch ratio of 1.58 and was found to be correlated along the cylinder, although the spatial behaviour is complex. This result suggests that the excitation force used in fretting wear models may need to be updated to include jet switching in the calculation.

Effect of Twin Delta-Winged Twisted-Tape on Thermal Performance of Heat Exchanger Tube

2013 ◽  
Vol 34 (15) ◽  
pp. 1278-1288 ◽  
Author(s):  
Smith Eiamsa-ard ◽  
Chayut Nuntadusit ◽  
Pongjet Promvonge
Keyword(s):  
Heat Exchanger ◽  
Thermal Performance ◽  
Twisted Tape ◽  
Heat Exchanger Tube ◽  
Exchanger Tube

Partial Admission Effects on the Stability of a Heat Exchanger Tube Array

1988 ◽  
Vol 110 (2) ◽  
pp. 194-198 ◽  
Author(s):  
L. F. Waring ◽  
D. S. Weaver
Keyword(s):  
Heat Exchanger ◽  
Elastic Stability ◽  
Uniform Flow ◽  
Heat Exchanger Tube ◽  
Tube Arrays ◽  
Partial Admission ◽  
Theoretical Predictions ◽  
Pitch Ratio ◽  
The Stability ◽  
Exchanger Tube

An experimental study is reported of the effects of partial admission on the fluid elastic stability of a heat exchanger tube array. The array geometry was a parallel triangular configuration with a pitch ratio of 1.47. Tests were conducted in a wind tunnel with uniform flow over from 33 to 100 percent of single span tubes. In these experiments, the flow location was also varied from center-span to the end supports. Additionally, tests were conducted with uniform flow over one span of two and three-span tube arrays. These results are compared with theoretical predictions.

scholarly journals Fluid flow and heat transfer enhancement in wings with combined solid ring twisted tape inserts circular heat exchanger tube

2019 ◽  
Vol 23 (6 Part B) ◽  
pp. 3893-3903
Author(s):  
Ravi Datt ◽  
Mangal Bhist ◽  
Alok Kothiyal ◽  
Rajesh Maithani ◽  
Anil Kumar
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Heat Exchanger ◽  
Hydrodynamic Performance ◽  
Turbulent Heat Transfer ◽  
Twisted Tape ◽  
Turbulent Heat ◽  
Heat Exchanger Tube ◽  
Circular Heat ◽  
Exchanger Tube

Experimental examination is carried out to study the turbulent heat transfer and fluid-flow characteristics in circular heat exchanger tube using combined wing with solid ring twisted tape inserts. A series of experiments has been performed with the range of Reynolds number varied from 3000 to 21000, number of twisted taped inserts, NTT, varied from 1.0 to 4.0 with constant value of other twisted tape parameters such as rings pitch ratio, dR /DT = 1.0, wing pitch ratio, PW /WT = = 3.0, and wing depth ratio, Wd /WT = 1.67. Based on the examined, turbulent heat transfer and fluid-flow in wing with combined solid ring twisted tape inserts results are compared with plain circular tube under same operating conditions. The experimental results show that the heat transfer is increased around 5.66 times than plane circular heat exchanger tube. The thermal and hydrodynamic performance parameter based on equal pumping power, ?p, was found to be highest for NTT = 3.0. The optimum value of thermal and hydrodynamic performance has been found to be 2.74 for Reynolds mumber of 3000 within the range of the parameters investigated. Multiple wings with solid rings twisted tape inserts have been also shown to be thermally as well as hydraulically better in comparison to other similar twisted tape insert geometries.

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