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Effects of the mainstream turbulence intensity and slot injection angle on the endwall cooling and phantom cooling of the vane suction side surface

Du, Kun LU ; Song, Liming; Li, Jun and Sunden, Bengt LU (2017) In International Journal of Heat and Mass Transfer 112. p.427-440
Abstract

In order to obtain better performance, gas turbines always operate with high inlet temperature. This contributes to a high level of thermal load on the first stage vane endwall. To ensure safe operation of a gas turbine within a proper temperature range, the cooling performance of the vane endwall must be further investigated. In the present study, effects of the mainstream turbulence and upstream coolant flow direction on the endwall cooling and vane suction side surface phantom cooling were numerically investigated. Three-dimensional (3D) Reynolds-averaged Navier–Stokes (RANS) equations combined with shear stress transport (SST) k-ω turbulence model were solved to conduct the numerical simulations on basis of the validated turbulence... (More)

In order to obtain better performance, gas turbines always operate with high inlet temperature. This contributes to a high level of thermal load on the first stage vane endwall. To ensure safe operation of a gas turbine within a proper temperature range, the cooling performance of the vane endwall must be further investigated. In the present study, effects of the mainstream turbulence and upstream coolant flow direction on the endwall cooling and vane suction side surface phantom cooling were numerically investigated. Three-dimensional (3D) Reynolds-averaged Navier–Stokes (RANS) equations combined with shear stress transport (SST) k-ω turbulence model were solved to conduct the numerical simulations on basis of the validated turbulence model. The calculated results indicate that both the adiabatic cooling effectiveness on the endwall and the phantom cooling effectiveness on the vane suction side surface are significantly influenced by slot injection angle. For α=-30°, the coolant injection is driven towards the vane suction side, which contributes to the lowest adiabatic cooling effectiveness level on the pressure side endwall and the highest phantom cooling effectiveness level on the vane suction side surface. With the increase of the slot injection angle, the adiabatic cooling effectiveness level on the pressure side endwall is enhanced significantly. In contrast, the phantom cooling (when the vane suction side is cooled by coolant originating from the endwall) of the vane suction side surface is reduced significantly. This is because a large slot injection angle leads to a large coolant momentum towards the pressure side. Moreover, the case with a smaller slot injection angle obtains a slightly higher area-averaged adiabatic cooling effectiveness level around the leading edge due to a relatively larger portion of coolant being confined near the leading edge. In addition, the inlet turbulence intensity has a small impact on the overall endwall cooling and the phantom cooling of the vane suction side surface compared to the slot injection angle.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Inlet turbulence intensity, Numerical simulation, Slot injection angle, Vane endwall
in
International Journal of Heat and Mass Transfer
volume
112
pages
14 pages
publisher
Pergamon
external identifiers
  • scopus:85019050912
  • wos:000404198600039
ISSN
0017-9310
DOI
10.1016/j.ijheatmasstransfer.2017.05.010
language
English
LU publication?
yes
id
47f183bc-151a-4607-b13e-5de054844a7f
date added to LUP
2017-05-29 11:05:22
date last changed
2017-09-18 11:37:42
@article{47f183bc-151a-4607-b13e-5de054844a7f,
  abstract     = {<p>In order to obtain better performance, gas turbines always operate with high inlet temperature. This contributes to a high level of thermal load on the first stage vane endwall. To ensure safe operation of a gas turbine within a proper temperature range, the cooling performance of the vane endwall must be further investigated. In the present study, effects of the mainstream turbulence and upstream coolant flow direction on the endwall cooling and vane suction side surface phantom cooling were numerically investigated. Three-dimensional (3D) Reynolds-averaged Navier–Stokes (RANS) equations combined with shear stress transport (SST) k-ω turbulence model were solved to conduct the numerical simulations on basis of the validated turbulence model. The calculated results indicate that both the adiabatic cooling effectiveness on the endwall and the phantom cooling effectiveness on the vane suction side surface are significantly influenced by slot injection angle. For α=-30°, the coolant injection is driven towards the vane suction side, which contributes to the lowest adiabatic cooling effectiveness level on the pressure side endwall and the highest phantom cooling effectiveness level on the vane suction side surface. With the increase of the slot injection angle, the adiabatic cooling effectiveness level on the pressure side endwall is enhanced significantly. In contrast, the phantom cooling (when the vane suction side is cooled by coolant originating from the endwall) of the vane suction side surface is reduced significantly. This is because a large slot injection angle leads to a large coolant momentum towards the pressure side. Moreover, the case with a smaller slot injection angle obtains a slightly higher area-averaged adiabatic cooling effectiveness level around the leading edge due to a relatively larger portion of coolant being confined near the leading edge. In addition, the inlet turbulence intensity has a small impact on the overall endwall cooling and the phantom cooling of the vane suction side surface compared to the slot injection angle.</p>},
  author       = {Du, Kun and Song, Liming and Li, Jun and Sunden, Bengt},
  issn         = {0017-9310},
  keyword      = {Inlet turbulence intensity,Numerical simulation,Slot injection angle,Vane endwall},
  language     = {eng},
  month        = {09},
  pages        = {427--440},
  publisher    = {Pergamon},
  series       = {International Journal of Heat and Mass Transfer},
  title        = {Effects of the mainstream turbulence intensity and slot injection angle on the endwall cooling and phantom cooling of the vane suction side surface},
  url          = {http://dx.doi.org/10.1016/j.ijheatmasstransfer.2017.05.010},
  volume       = {112},
  year         = {2017},
}