Advanced

Flow pattern and heat transfer past two tandem arranged cylinders with oscillating inlet velocity

Liu, Jian LU ; Xie, Gongnan LU and Sundén, Bengt LU (2017) In Applied Thermal Engineering 120. p.614-625
Abstract

Unsteady laminar convective fluid flow and heat transfer past two cylinders in tandem arrangement is investigated. Besides forced mixing by the natural vortex streets, extra imposed oscillating inlet velocity are considered. The lift and drag coefficients and Strouhal number for a single cylinder and their dependence on Reynolds number are also provided to validate the calculations with previous experiments. Different frequencies and amplitudes of the oscillating flows are set as inlet boundary conditions. For the cycle effect, at some specified points of the cycle ratios, the heat transfer enhancement of the upstream cylinder and the downstream cylinder are relatively larger due to the combined-effect of the natural vortex streets and... (More)

Unsteady laminar convective fluid flow and heat transfer past two cylinders in tandem arrangement is investigated. Besides forced mixing by the natural vortex streets, extra imposed oscillating inlet velocity are considered. The lift and drag coefficients and Strouhal number for a single cylinder and their dependence on Reynolds number are also provided to validate the calculations with previous experiments. Different frequencies and amplitudes of the oscillating flows are set as inlet boundary conditions. For the cycle effect, at some specified points of the cycle ratios, the heat transfer enhancement of the upstream cylinder and the downstream cylinder are relatively larger due to the combined-effect of the natural vortex streets and the imposed oscillating inlet flows. The interaction between the natural vortex streets and imposed oscillating inlet flow leads to non-regular shaped vortices with increased flow mixing. For the amplitude effect, Nusselt numbers of the two cylinders are both greatly increased with increased amplitude ratios. With increased amplitude ratios, the vortex street expands and vibrates in a larger region which leads to stronger flow mixing and higher heat transfer. Generally, oscillating inlet flows can efficiently increase the heat transfer of two cylinders in crossflow without increasing the flow rate of the coolants.

(Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Amplitude ratio, Cycle ratio, Heat transfer, Oscillating inlet flows, Vortex streets
in
Applied Thermal Engineering
volume
120
pages
12 pages
publisher
Elsevier
external identifiers
  • scopus:85017585538
  • wos:000401593000060
ISSN
1359-4311
DOI
10.1016/j.applthermaleng.2017.04.032
language
English
LU publication?
yes
id
6a54e220-c9e9-4ef9-9a8b-73362bfe5360
date added to LUP
2017-05-08 10:19:25
date last changed
2017-09-18 11:35:15
@article{6a54e220-c9e9-4ef9-9a8b-73362bfe5360,
  abstract     = {<p>Unsteady laminar convective fluid flow and heat transfer past two cylinders in tandem arrangement is investigated. Besides forced mixing by the natural vortex streets, extra imposed oscillating inlet velocity are considered. The lift and drag coefficients and Strouhal number for a single cylinder and their dependence on Reynolds number are also provided to validate the calculations with previous experiments. Different frequencies and amplitudes of the oscillating flows are set as inlet boundary conditions. For the cycle effect, at some specified points of the cycle ratios, the heat transfer enhancement of the upstream cylinder and the downstream cylinder are relatively larger due to the combined-effect of the natural vortex streets and the imposed oscillating inlet flows. The interaction between the natural vortex streets and imposed oscillating inlet flow leads to non-regular shaped vortices with increased flow mixing. For the amplitude effect, Nusselt numbers of the two cylinders are both greatly increased with increased amplitude ratios. With increased amplitude ratios, the vortex street expands and vibrates in a larger region which leads to stronger flow mixing and higher heat transfer. Generally, oscillating inlet flows can efficiently increase the heat transfer of two cylinders in crossflow without increasing the flow rate of the coolants.</p>},
  author       = {Liu, Jian and Xie, Gongnan and Sundén, Bengt},
  issn         = {1359-4311},
  keyword      = {Amplitude ratio,Cycle ratio,Heat transfer,Oscillating inlet flows,Vortex streets},
  language     = {eng},
  month        = {06},
  pages        = {614--625},
  publisher    = {Elsevier},
  series       = {Applied Thermal Engineering},
  title        = {Flow pattern and heat transfer past two tandem arranged cylinders with oscillating inlet velocity},
  url          = {http://dx.doi.org/10.1016/j.applthermaleng.2017.04.032},
  volume       = {120},
  year         = {2017},
}