Effect of Reynolds Number and Property Variation on Fluid Flow and Heat Transfer in the Entrance Region of a Turbine Blade Internal-Cooling Channel

Internal cooling is one of the effective techniques to cool turbine blades from inside. This internal cooling is achieved by pumping a relatively cold fluid through the internal-cooling channels. These channels are fed through short channels placed at the root of the turbine blade, usually called en...

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Main Authors: R. Ben-Mansour, L. Al-Hadhrami
Format: Article
Language:English
Published: Wiley 2005-01-01
Series:International Journal of Rotating Machinery
Subjects:
Online Access:http://dx.doi.org/10.1155/IJRM.2005.36
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author R. Ben-Mansour
L. Al-Hadhrami
author_facet R. Ben-Mansour
L. Al-Hadhrami
author_sort R. Ben-Mansour
collection DOAJ
description Internal cooling is one of the effective techniques to cool turbine blades from inside. This internal cooling is achieved by pumping a relatively cold fluid through the internal-cooling channels. These channels are fed through short channels placed at the root of the turbine blade, usually called entrance region channels. The entrance region at the root of the turbine blade usually has a different geometry than the internal-cooling channel of the blade. This study investigates numerically the fluid flow and heat transfer in one-pass smooth isothermally heated channel using the RNG k−ε model. The effect of Reynolds number on the flow and heat transfer characteristics has been studied for two mass flow rate ratios (1/1 and 1/2) for the same cooling channel. The Reynolds number was varied between 10 000 and 50 000. The study has shown that the cooling channel goes through hydrodynamic and thermal development which necessitates a detailed flow and heat transfer study to evaluate the pressure drop and heat transfer rates. For the case of unbalanced mass flow rate ratio, a maximum difference of 8.9% in the heat transfer rate between the top and bottom surfaces occurs at Re=10 000 while the total heat transfer rate from both surfaces is the same for the balanced mass flow rate case. The effect of temperature-dependent property variation showed a small change in the heat transfer rates when all properties were allowed to vary with temperature. However, individual effects can be significant such as the effect of density variation, which resulted in as much as 9.6% reduction in the heat transfer rate.
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spelling doaj-art-4646b083d95a45e4a6747e7e57c76bfc2025-08-20T02:37:48ZengWileyInternational Journal of Rotating Machinery1023-621X1542-30342005-01-0120051364410.1155/IJRM.2005.36Effect of Reynolds Number and Property Variation on Fluid Flow and Heat Transfer in the Entrance Region of a Turbine Blade Internal-Cooling ChannelR. Ben-Mansour0L. Al-Hadhrami1Department of Mechanical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi ArabiaDepartment of Mechanical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi ArabiaInternal cooling is one of the effective techniques to cool turbine blades from inside. This internal cooling is achieved by pumping a relatively cold fluid through the internal-cooling channels. These channels are fed through short channels placed at the root of the turbine blade, usually called entrance region channels. The entrance region at the root of the turbine blade usually has a different geometry than the internal-cooling channel of the blade. This study investigates numerically the fluid flow and heat transfer in one-pass smooth isothermally heated channel using the RNG k−ε model. The effect of Reynolds number on the flow and heat transfer characteristics has been studied for two mass flow rate ratios (1/1 and 1/2) for the same cooling channel. The Reynolds number was varied between 10 000 and 50 000. The study has shown that the cooling channel goes through hydrodynamic and thermal development which necessitates a detailed flow and heat transfer study to evaluate the pressure drop and heat transfer rates. For the case of unbalanced mass flow rate ratio, a maximum difference of 8.9% in the heat transfer rate between the top and bottom surfaces occurs at Re=10 000 while the total heat transfer rate from both surfaces is the same for the balanced mass flow rate case. The effect of temperature-dependent property variation showed a small change in the heat transfer rates when all properties were allowed to vary with temperature. However, individual effects can be significant such as the effect of density variation, which resulted in as much as 9.6% reduction in the heat transfer rate.http://dx.doi.org/10.1155/IJRM.2005.36coolingbladeentranceflowheatvariable properties.
spellingShingle R. Ben-Mansour
L. Al-Hadhrami
Effect of Reynolds Number and Property Variation on Fluid Flow and Heat Transfer in the Entrance Region of a Turbine Blade Internal-Cooling Channel
International Journal of Rotating Machinery
cooling
blade
entrance
flow
heat
variable properties.
title Effect of Reynolds Number and Property Variation on Fluid Flow and Heat Transfer in the Entrance Region of a Turbine Blade Internal-Cooling Channel
title_full Effect of Reynolds Number and Property Variation on Fluid Flow and Heat Transfer in the Entrance Region of a Turbine Blade Internal-Cooling Channel
title_fullStr Effect of Reynolds Number and Property Variation on Fluid Flow and Heat Transfer in the Entrance Region of a Turbine Blade Internal-Cooling Channel
title_full_unstemmed Effect of Reynolds Number and Property Variation on Fluid Flow and Heat Transfer in the Entrance Region of a Turbine Blade Internal-Cooling Channel
title_short Effect of Reynolds Number and Property Variation on Fluid Flow and Heat Transfer in the Entrance Region of a Turbine Blade Internal-Cooling Channel
title_sort effect of reynolds number and property variation on fluid flow and heat transfer in the entrance region of a turbine blade internal cooling channel
topic cooling
blade
entrance
flow
heat
variable properties.
url http://dx.doi.org/10.1155/IJRM.2005.36
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AT lalhadhrami effectofreynoldsnumberandpropertyvariationonfluidflowandheattransferintheentranceregionofaturbinebladeinternalcoolingchannel