Non-axisymmetric Endwall film cooling characteristics considering the influences of cylindrical holes and laidback fan-shaped holes
(2024) In International Journal of Heat and Mass Transfer 225.- Abstract
Flow fields near the turbine vane endwall are complicated due to the endwall cross flows. The use of a non-axisymmetric endwall is regarded as an efficient technique to reduce the lateral pressure difference, decreasing the endwall cross flow. Numerical analysis was performed to determine how the non-axisymmetric endwall affected the vortex structure and heat transfer level. The cooling performance was investigated with cylindrical and laidback fan-shaped holes (7–7–7), which were arranged in rows aligned in the axial direction. The results showed that the non-axisymmetric endwall could significantly reduce the circumferential pressure difference and suppress the growth of the passage vortex, and the area-averaged heat transfer... (More)
Flow fields near the turbine vane endwall are complicated due to the endwall cross flows. The use of a non-axisymmetric endwall is regarded as an efficient technique to reduce the lateral pressure difference, decreasing the endwall cross flow. Numerical analysis was performed to determine how the non-axisymmetric endwall affected the vortex structure and heat transfer level. The cooling performance was investigated with cylindrical and laidback fan-shaped holes (7–7–7), which were arranged in rows aligned in the axial direction. The results showed that the non-axisymmetric endwall could significantly reduce the circumferential pressure difference and suppress the growth of the passage vortex, and the area-averaged heat transfer coefficient was reduced by 3.34%. The outlet area of the film hole was altered by the non-axisymmetric endwall, and the over-cooled regions may have appeared as a result of the excessive area increase. The influence of the non-axisymmetric endwall was concentrated at 0.4 < Z/Cax < 1.0 for the cylindrical hole. With the increase in M, the film cooling effectiveness of the non-axisymmetric endwall attained a higher level than that of the flat endwall. For the laidback fan-shaped hole, the effect of the non-axisymmetric endwall was confined within 0.25 < Z/Cax < 1.0. The half-period trigonometric function of the non-axisymmetric endwall (HTFN) achieved the optimal cooling performance for three blowing ratios. However, the periodic trigonometric function of the non-axisymmetric endwall (PTFN) only outperformed the flat endwall when M= 1.5.
(Less)
- author
- Du, Kun ; Jia, Yihao ; Liu, Cunliang and Sunden, Bengt LU
- organization
- publishing date
- 2024-06-15
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Aerodynamic characteristics, Film cooling, Laidback Fan-shaped Hole, Non-axisymmetric endwall
- in
- International Journal of Heat and Mass Transfer
- volume
- 225
- article number
- 125403
- publisher
- Pergamon Press Ltd.
- external identifiers
-
- scopus:85188026662
- ISSN
- 0017-9310
- DOI
- 10.1016/j.ijheatmasstransfer.2024.125403
- language
- English
- LU publication?
- yes
- id
- 7cd16412-cd78-49fd-8772-9740a059ddbf
- date added to LUP
- 2024-04-04 13:14:04
- date last changed
- 2024-04-04 13:15:13
@article{7cd16412-cd78-49fd-8772-9740a059ddbf, abstract = {{<p>Flow fields near the turbine vane endwall are complicated due to the endwall cross flows. The use of a non-axisymmetric endwall is regarded as an efficient technique to reduce the lateral pressure difference, decreasing the endwall cross flow. Numerical analysis was performed to determine how the non-axisymmetric endwall affected the vortex structure and heat transfer level. The cooling performance was investigated with cylindrical and laidback fan-shaped holes (7–7–7), which were arranged in rows aligned in the axial direction. The results showed that the non-axisymmetric endwall could significantly reduce the circumferential pressure difference and suppress the growth of the passage vortex, and the area-averaged heat transfer coefficient was reduced by 3.34%. The outlet area of the film hole was altered by the non-axisymmetric endwall, and the over-cooled regions may have appeared as a result of the excessive area increase. The influence of the non-axisymmetric endwall was concentrated at 0.4 < Z/C<sub>ax</sub> < 1.0 for the cylindrical hole. With the increase in M, the film cooling effectiveness of the non-axisymmetric endwall attained a higher level than that of the flat endwall. For the laidback fan-shaped hole, the effect of the non-axisymmetric endwall was confined within 0.25 < Z/C<sub>ax</sub> < 1.0. The half-period trigonometric function of the non-axisymmetric endwall (HTFN) achieved the optimal cooling performance for three blowing ratios. However, the periodic trigonometric function of the non-axisymmetric endwall (PTFN) only outperformed the flat endwall when M= 1.5.</p>}}, author = {{Du, Kun and Jia, Yihao and Liu, Cunliang and Sunden, Bengt}}, issn = {{0017-9310}}, keywords = {{Aerodynamic characteristics; Film cooling; Laidback Fan-shaped Hole; Non-axisymmetric endwall}}, language = {{eng}}, month = {{06}}, publisher = {{Pergamon Press Ltd.}}, series = {{International Journal of Heat and Mass Transfer}}, title = {{Non-axisymmetric Endwall film cooling characteristics considering the influences of cylindrical holes and laidback fan-shaped holes}}, url = {{http://dx.doi.org/10.1016/j.ijheatmasstransfer.2024.125403}}, doi = {{10.1016/j.ijheatmasstransfer.2024.125403}}, volume = {{225}}, year = {{2024}}, }