Effect of forward expansion angle on film cooling characteristics of shaped holes
According to the design requirements of high-temperature combustion chamber, an advanced shaped hole structure was designed for film cooling. Numerical method was applied in this study to investigate the flow and heat transfer characteristics of shaped holes and compared with those of cylindrical ho...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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De Gruyter
2020-07-01
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| Series: | Open Physics |
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| Online Access: | https://doi.org/10.1515/phys-2020-0130 |
| _version_ | 1818578607230943232 |
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| author | Zhang Bo Lin Li-Bing Li Ji-Quan Zhang Na-Ru Ji Hong-Hu |
| author_facet | Zhang Bo Lin Li-Bing Li Ji-Quan Zhang Na-Ru Ji Hong-Hu |
| author_sort | Zhang Bo |
| collection | DOAJ |
| description | According to the design requirements of high-temperature combustion chamber, an advanced shaped hole structure was designed for film cooling. Numerical method was applied in this study to investigate the flow and heat transfer characteristics of shaped holes and compared with those of cylindrical holes. The influence of the forward expansion angle of shaped holes on the flow and heat transfer was studied. The results show that compared to cylindrical holes, the diffused structure of shaped holes decreases the momentum of jet flow, improves the adhesion characteristics of the cooling air film, increases the diffusion of the coolant air outflow and improves the cooling efficiency between adjacent columns of holes in the lateral direction. When the forward expansion angle increases, the expansion section induced the flow vortex, which reduces the radial velocity of coolant flow and enhances the diffusion of cooling air film both in streamwise and spanwise directions. However, as the forward expansion angle increases further, the scale of vortex inside the shaped hole grows. Too large vortex inside the shaped hole increases the coolant eject angle, which weakens the film covering effect. Additionally, the shaped hole results in an increase in lateral spreading and enhances the cooling effect between adjacent columns of the film hole. The enhancement of the film cooling characteristics is due to the change in the shape of the film hole, resulting in the enhancement of the flow vortex, which induces complicated secondary flow. |
| first_indexed | 2024-12-16T06:48:30Z |
| format | Article |
| id | doaj.art-54ff5dbce27e4cb9a3798af56c18c380 |
| institution | Directory Open Access Journal |
| issn | 2391-5471 |
| language | English |
| last_indexed | 2024-12-16T06:48:30Z |
| publishDate | 2020-07-01 |
| publisher | De Gruyter |
| record_format | Article |
| series | Open Physics |
| spelling | doaj.art-54ff5dbce27e4cb9a3798af56c18c3802022-12-21T22:40:29ZengDe GruyterOpen Physics2391-54712020-07-0118130231410.1515/phys-2020-0130phys-2020-0130Effect of forward expansion angle on film cooling characteristics of shaped holesZhang Bo0Lin Li-Bing1Li Ji-Quan2Zhang Na-Ru3Ji Hong-Hu4Jiangsu Province Key Laboratory of Aerospace Power System, College of Energy and Power, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, ChinaJiangsu Province Key Laboratory of Aerospace Power System, College of Energy and Power, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, ChinaJiangsu Province Key Laboratory of Aerospace Power System, College of Energy and Power, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, ChinaJiangsu Province Key Laboratory of Aerospace Power System, College of Energy and Power, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, ChinaJiangsu Province Key Laboratory of Aerospace Power System, College of Energy and Power, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, ChinaAccording to the design requirements of high-temperature combustion chamber, an advanced shaped hole structure was designed for film cooling. Numerical method was applied in this study to investigate the flow and heat transfer characteristics of shaped holes and compared with those of cylindrical holes. The influence of the forward expansion angle of shaped holes on the flow and heat transfer was studied. The results show that compared to cylindrical holes, the diffused structure of shaped holes decreases the momentum of jet flow, improves the adhesion characteristics of the cooling air film, increases the diffusion of the coolant air outflow and improves the cooling efficiency between adjacent columns of holes in the lateral direction. When the forward expansion angle increases, the expansion section induced the flow vortex, which reduces the radial velocity of coolant flow and enhances the diffusion of cooling air film both in streamwise and spanwise directions. However, as the forward expansion angle increases further, the scale of vortex inside the shaped hole grows. Too large vortex inside the shaped hole increases the coolant eject angle, which weakens the film covering effect. Additionally, the shaped hole results in an increase in lateral spreading and enhances the cooling effect between adjacent columns of the film hole. The enhancement of the film cooling characteristics is due to the change in the shape of the film hole, resulting in the enhancement of the flow vortex, which induces complicated secondary flow.https://doi.org/10.1515/phys-2020-0130film coolingshaped holeexpansion anglelateral diffusion |
| spellingShingle | Zhang Bo Lin Li-Bing Li Ji-Quan Zhang Na-Ru Ji Hong-Hu Effect of forward expansion angle on film cooling characteristics of shaped holes Open Physics film cooling shaped hole expansion angle lateral diffusion |
| title | Effect of forward expansion angle on film cooling characteristics of shaped holes |
| title_full | Effect of forward expansion angle on film cooling characteristics of shaped holes |
| title_fullStr | Effect of forward expansion angle on film cooling characteristics of shaped holes |
| title_full_unstemmed | Effect of forward expansion angle on film cooling characteristics of shaped holes |
| title_short | Effect of forward expansion angle on film cooling characteristics of shaped holes |
| title_sort | effect of forward expansion angle on film cooling characteristics of shaped holes |
| topic | film cooling shaped hole expansion angle lateral diffusion |
| url | https://doi.org/10.1515/phys-2020-0130 |
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