Numerical study on flow and heat transfer of a finned-tube heat exchanger with trapezoid vortex generators in CO2 lasers

2019 ◽  
Author(s):  
Hui liu ◽  
xiang yan ◽  
jianbao yue ◽  
heng zhao
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Numerical Study ◽  
Finned Tube ◽  
Vortex Generators ◽  
Co2 Lasers ◽  
Tube Heat Exchanger ◽  
Flow And Heat Transfer ◽  
Finned Tube Heat Exchanger

Flow and Heat Transfer From the Annular Fin Heat Exchanger Using Winglet Type Vortex Generators

2013 ◽  
Author(s):  
Basanta Kumar Rana ◽  
Amaresh Dalal ◽  
Gautam Biswas
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Heat Exchanger ◽  
Thermal Boundary Layer ◽  
Numerical Study ◽  
Three Dimensional ◽  
Vortex Generators ◽  
Flow And Heat Transfer ◽  
Finned Tube Heat Exchanger ◽  
Annular Fin

A numerical study of three-dimensional flow and heat transfer from the annular finned tube heat exchanger with built-in delta winglets is carried out. The delta winglets type vortex generators which are placed on the annular fin surface in the neighborhood of the cylinder are used to enhance the heat transfer. The winglets are placed in common flow orientation. Longitudinal vortices develop along the side edge of the delta winglets due to the pressure difference between the front surface (facing the flow) and back surface. These vortices interact with thermal boundary layer and produce a three dimensional swirling flow that mixes near wall fluid with the midstream. Thus the thermal boundary layer is disrupted and heat transfer is enhanced. The investigations are carried out for four different Reynolds number (100, 500 and 1000) and four different angles of attack (35°, 40°, 45°, 50°) for common flow up (CFU) configuration. It is found that heat transfer increases about 11% for Re = 1000 with angle of attack 40°.

Effect of tube shape on the performance of a fin and tube heat exchanger

2020 ◽  
Vol 14 (2) ◽  
pp. 6709-6718
Author(s):  
Djamel Sahel ◽  
Houari Ameur ◽  
Mustapha Mellal
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Numerical Study ◽  
Reynolds Numbers ◽  
Finned Tube ◽  
Moderate Pressure ◽  
Tube Heat Exchanger ◽  
Finned Tube Heat Exchanger ◽  
Tube Shape ◽  
Different Shapes

A numerical study is carried out to test the effect of tube shape on heat transfer and fluid flow in a finned tube heat exchanger. The effects of different shapes (circular, flat, elliptical and oval in both orientations: left and right) are analyzed. The simulations are carried out for two-dimensional and external flow of an incompressible fluid with Reynolds numbers varying between 3000 and 20000. The results obtained indicate that the shape of the tube directly affects the thermal and dynamic behaviors of a fin and tube heat exchanger. Where the circular tube ensures higher heat transfer coefficient of about 18% than the flat tube, and it generate a moderate pressure drop of about 10% in the same conditions. Also, some reliable empirical correlations are proposed to predict the Nusselt number and the friction factor.

CFD Design and Analysis on Circular Slotted Fin Surfaces of Two-Row Tubes Heat Exchangers

2013 ◽  
Vol 732-733 ◽  
pp. 186-189
Author(s):  
Jing Zhao Zhang
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Three Dimensional ◽  
Finned Tube ◽  
Percentage Increase ◽  
Number Range ◽  
Tube Heat Exchanger ◽  
Flow And Heat Transfer ◽  
Finned Tube Heat Exchanger ◽  
Good Heat

A numerical investigation of the flow and heat transfer in a two-row finned-tube heat exchanger is conducted with a three-dimensional conjugated model using the CFD software. The results show that, compared to the quadrate slotted fin, the circular slotted fin have good heat transfer performance in that the percentage increase in heat transfer is higher than that in the friction factor. Within the Reynolds number range compared ( from 1,270 to 8,892), the Nusselt number of new slit 1 is about 25.6-61.6% and 20.8-57.5%, while new slit 2 is about 26.8-33.6% and 25.8-33.0%, higher than that of the quadrate slotted fin surface at identical pressure drop and the identical pumping power, respectively. For the two-row plate fin-and-tube heat exchanger, new slit 2 is recommended for the use in air-conditioning because its integrative design.

scholarly journals Statistical analysis of entropy generation in longitudinally finned tube heat exchanger with shell side nanofluid by a single phase approach

2016 ◽  
Vol 37 (2) ◽  
pp. 3-22 ◽  
Author(s):  
Pavan Kumar Konchada ◽  
Vinay Pv ◽  
Varaprasad Bhemuni
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Entropy Generation ◽  
Single Phase ◽  
Pure Water ◽  
Finned Tube ◽  
Shell Side ◽  
Tube Heat Exchanger ◽  
Phase Approach ◽  
Finned Tube Heat Exchanger

AbstractThe presence of nanoparticles in heat exchangers ascertained increment in heat transfer. The present work focuses on heat transfer in a longitudinal finned tube heat exchanger. Experimentation is done on longitudinal finned tube heat exchanger with pure water as working fluid and the outcome is compared numerically using computational fluid dynamics (CFD) package based on finite volume method for different flow rates. Further 0.8% volume fraction of aluminum oxide (Al2O3) nanofluid is considered on shell side. The simulated nanofluid analysis has been carried out using single phase approach in CFD by updating the user-defined functions and expressions with thermophysical properties of the selected nanofluid. These results are thereafter compared against the results obtained for pure water as shell side fluid. Entropy generated due to heat transfer and fluid flow is calculated for the nanofluid. Analysis of entropy generation is carried out using the Taguchi technique. Analysis of variance (ANOVA) results show that the inlet temperature on shell side has more pronounced effect on entropy generation.

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