scholarly journals A numerical study on helical vortices induced by a short twisted tape in a circular pipe

2015 ◽  
Vol 5 ◽  
pp. 134-142 ◽  
Author(s):  
Wen Liu ◽  
Bofeng Bai
Keyword(s):  
Numerical Study ◽  
Circular Pipe ◽  
Twisted Tape ◽  
Helical Vortices

scholarly journals CONVECTIVE HEAT TRANSFER AND POWER SAVING APPLICATION OF SI BASED NANOPARTICLES IN A CIRCULAR PIPE

2020 ◽  
Vol 50 (4) ◽  
pp. 321-327
Author(s):  
Md Insiat Islam Rabby ◽  
Farzad Hossain ◽  
S.A.M. Shafwat Amin ◽  
Tazeen Afrin Mumu ◽  
MD Ashraf Hossain Bhuiyan ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Base Fluid ◽  
Volume Fraction ◽  
Numerical Study ◽  
Convective Heat Transfer Coefficient ◽  
Circular Pipe ◽  
Working Fluid ◽  
Pumping Power

A numerical study of laminar forced convection heat transfer for the fully developed region inside a circular pipe filled with Si based nanoparticle is presented for investigating the parameters of heat transfer. Four Si based nanoparticles Si, SiC, SiO2, Si3N4 with 1-5% volume fraction have been mixed with water to prepare nanofluids which is used for working fluid to flow over a circular pipe with 5mm diameter and 700mm length. Heat transfer characteristics and pumping power have been calculated at fully developed region with constant heat flux condition on pipe wall to identify the heat transfer enhancement ratio and pumping power reduction ratio among base fluid water and each nanofluids. It is worth mentioning that utilizing SiC nanoparticle shows not only the highest increment of Nusselt number and convective heat transfer coefficient but also the highest decrement of pumping power requirement and FOM in comparison to the base fluid.

A Numerical Study of the Flow and Heat Transfer Characteristics of Outward Convex Corrugated Tubes With Twisted-Tape Insert

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Longbin Yang ◽  
Huaizhi Han ◽  
Yanjun Li ◽  
Xiaoming Li
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Performance ◽  
Swirling Flow ◽  
Numerical Study ◽  
Twisted Tape ◽  
Transfer Performance ◽  
Heat Transfer Characteristics ◽  
Corrugated Tube ◽  
Flow And Heat Transfer ◽  
Flow Heat

This work presents a mathematical model for simulating the swirling flow in an outward convex corrugated tube with twisted-tape insert (CT). The synergistic effect on the flow, heat transfer, and friction loss behaviors between the surface-based and fluid-based enhancements is numerically investigated. Renormalized group (RNG) k-ε turbulence model applied in our paper is verified by comparing with experimental results investigated by Manglik and Bergles. Comparisons of the CT and smooth tube with twisted-tape insert (ST) plots are confirmed to investigate the performance differences between them. When comparing the performance of the CT against the ST, the maximum ratio of Nusselt number (Nuc/Nus), ratio of friction factor (f/fs), and overall heat transfer performance (η) values realized in the CT are 1.36, 1.53, and 1.15 times higher, respectively, than the maximum values for those same variables in the ST.

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