Heat transfer enhancement and turbulent flow in a rectangular channel using perforated ribs with inclined holes
(2019) In Journal of Heat Transfer 141(4).- Abstract
In internal cooling passages in a turbine blade, rib structures are widely applied to augment convective heat transfer by the coolant passing through over the ribbed surfaces. This study concentrates on perforated 90 deg ribs with inclined holes in a cooling duct with rectangular cross section, aiming at improving the perforated holes with additional secondary flows caused by inclined hole arrangements. Two sets of perforated ribs are used in the experiments with the inclined angle of the holes changing from 0 deg to 45 deg and the cross section are, respectively, circular and square. Steady-state liquid crystal thermography (LCT) is applied to measure the ribbed surface temperature and obtain corresponding convective heat transfer... (More)
In internal cooling passages in a turbine blade, rib structures are widely applied to augment convective heat transfer by the coolant passing through over the ribbed surfaces. This study concentrates on perforated 90 deg ribs with inclined holes in a cooling duct with rectangular cross section, aiming at improving the perforated holes with additional secondary flows caused by inclined hole arrangements. Two sets of perforated ribs are used in the experiments with the inclined angle of the holes changing from 0 deg to 45 deg and the cross section are, respectively, circular and square. Steady-state liquid crystal thermography (LCT) is applied to measure the ribbed surface temperature and obtain corresponding convective heat transfer coefficients (HTCs). Two turbulence models, i.e., the k-ω shear stress transportation (SST) model and the detached eddy simulation (DES) model, are used in the numerical studies to simulate the flow fields. All the inclined cases have slightly larger overall averaged Nusselt number (Nu) than with straight cases. The enhancement ratio is approximately 1.85-4.94%. The averaged Nu in the half portion against the inclined direction is enlarged for the inclined hole cases. The inclined hole cases usually have smaller averaged Nu in the half portion along the inclined direction. For the straight hole case and small inclined angle case, the penetrated flows mix with the mainstream flows at the perforated regions. When the inclined angle is larger, the penetrated flows are pushed to the inclined direction and mixing with the approaching flows occurs just at the side of the inclined direction.
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- author
- Liu, Jian LU ; Hussain, Safeer LU ; Wang, Wei ; Wang, Lei LU ; Xie, Gongnan LU and Sundén, Bengt LU
- organization
- publishing date
- 2019
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- DES model, inclined holes, LCT, perforated ribs, recirculating flows
- in
- Journal of Heat Transfer
- volume
- 141
- issue
- 4
- article number
- 041702
- publisher
- American Society Of Mechanical Engineers (ASME)
- external identifiers
-
- scopus:85062636856
- ISSN
- 0022-1481
- DOI
- 10.1115/1.4042841
- language
- English
- LU publication?
- yes
- id
- 028ecc77-f4de-4267-983e-131b48d23679
- date added to LUP
- 2019-03-19 11:04:39
- date last changed
- 2025-04-04 14:59:28
@article{028ecc77-f4de-4267-983e-131b48d23679,
abstract = {{<p>In internal cooling passages in a turbine blade, rib structures are widely applied to augment convective heat transfer by the coolant passing through over the ribbed surfaces. This study concentrates on perforated 90 deg ribs with inclined holes in a cooling duct with rectangular cross section, aiming at improving the perforated holes with additional secondary flows caused by inclined hole arrangements. Two sets of perforated ribs are used in the experiments with the inclined angle of the holes changing from 0 deg to 45 deg and the cross section are, respectively, circular and square. Steady-state liquid crystal thermography (LCT) is applied to measure the ribbed surface temperature and obtain corresponding convective heat transfer coefficients (HTCs). Two turbulence models, i.e., the k-ω shear stress transportation (SST) model and the detached eddy simulation (DES) model, are used in the numerical studies to simulate the flow fields. All the inclined cases have slightly larger overall averaged Nusselt number (Nu) than with straight cases. The enhancement ratio is approximately 1.85-4.94%. The averaged Nu in the half portion against the inclined direction is enlarged for the inclined hole cases. The inclined hole cases usually have smaller averaged Nu in the half portion along the inclined direction. For the straight hole case and small inclined angle case, the penetrated flows mix with the mainstream flows at the perforated regions. When the inclined angle is larger, the penetrated flows are pushed to the inclined direction and mixing with the approaching flows occurs just at the side of the inclined direction.</p>}},
author = {{Liu, Jian and Hussain, Safeer and Wang, Wei and Wang, Lei and Xie, Gongnan and Sundén, Bengt}},
issn = {{0022-1481}},
keywords = {{DES model; inclined holes; LCT; perforated ribs; recirculating flows}},
language = {{eng}},
number = {{4}},
publisher = {{American Society Of Mechanical Engineers (ASME)}},
series = {{Journal of Heat Transfer}},
title = {{Heat transfer enhancement and turbulent flow in a rectangular channel using perforated ribs with inclined holes}},
url = {{http://dx.doi.org/10.1115/1.4042841}},
doi = {{10.1115/1.4042841}},
volume = {{141}},
year = {{2019}},
}