Large eddy simulation of weakly compressible turbulent flows around an airfoil
The purpose of this study is to develop a numerical method for turbulent flows at low Mach number range. To account for the weak compressibility, we modify the time marching method of the usual incompressible scheme which is based on the elliptic equation for pressure. To deal with high Reynolds num...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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The Japan Society of Mechanical Engineers
2014-10-01
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| Series: | Journal of Fluid Science and Technology |
| Subjects: | |
| Online Access: | https://www.jstage.jst.go.jp/article/jfst/9/4/9_2014jfst0063/_pdf/-char/en |
| _version_ | 1819282328795480064 |
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| author | Changhwa HAN Takeo KAJISHIMA |
| author_facet | Changhwa HAN Takeo KAJISHIMA |
| author_sort | Changhwa HAN |
| collection | DOAJ |
| description | The purpose of this study is to develop a numerical method for turbulent flows at low Mach number range. To account for the weak compressibility, we modify the time marching method of the usual incompressible scheme which is based on the elliptic equation for pressure. To deal with high Reynolds number flows appropriately, we propose a new one-equation subgrid scale model (SGS). In this model, the concept of coherent structure function model is introduced to treat the energy transfer from grid scale to SGS portion of turbulence kinetic energy. The feature of our one-equation SGS model is that the energy production rate of SGS kinetic energy is calculated without the dynamic procedure, and any parameters such as the friction velocity on the wall or distance from the wall are not necessary. The new one-equation SGS model is incorporated into the weakly compressible scheme to treat a small density variation. Computational examinations have been conducted for fully developed turbulent flows in a plane channel and turbulent flows around NACA0012 airfoil at low Mach number, and have shown satisfactory results. We show that the consideration of the density variation even in low Mach number flows is essential to reproduce the pressure fluctuation and vortical structure appropriately. |
| first_indexed | 2024-12-24T01:13:51Z |
| format | Article |
| id | doaj.art-766dc63d84704dd1bea649a3c173175b |
| institution | Directory Open Access Journal |
| issn | 1880-5558 |
| language | English |
| last_indexed | 2024-12-24T01:13:51Z |
| publishDate | 2014-10-01 |
| publisher | The Japan Society of Mechanical Engineers |
| record_format | Article |
| series | Journal of Fluid Science and Technology |
| spelling | doaj.art-766dc63d84704dd1bea649a3c173175b2022-12-21T17:22:48ZengThe Japan Society of Mechanical EngineersJournal of Fluid Science and Technology1880-55582014-10-0194JFST0063JFST006310.1299/jfst.2014jfst0063jfstLarge eddy simulation of weakly compressible turbulent flows around an airfoilChanghwa HAN0Takeo KAJISHIMA1Graduate School of Engineering, Osaka UniversityDepartment of Mechanical Engineering, Osaka UniversityThe purpose of this study is to develop a numerical method for turbulent flows at low Mach number range. To account for the weak compressibility, we modify the time marching method of the usual incompressible scheme which is based on the elliptic equation for pressure. To deal with high Reynolds number flows appropriately, we propose a new one-equation subgrid scale model (SGS). In this model, the concept of coherent structure function model is introduced to treat the energy transfer from grid scale to SGS portion of turbulence kinetic energy. The feature of our one-equation SGS model is that the energy production rate of SGS kinetic energy is calculated without the dynamic procedure, and any parameters such as the friction velocity on the wall or distance from the wall are not necessary. The new one-equation SGS model is incorporated into the weakly compressible scheme to treat a small density variation. Computational examinations have been conducted for fully developed turbulent flows in a plane channel and turbulent flows around NACA0012 airfoil at low Mach number, and have shown satisfactory results. We show that the consideration of the density variation even in low Mach number flows is essential to reproduce the pressure fluctuation and vortical structure appropriately.https://www.jstage.jst.go.jp/article/jfst/9/4/9_2014jfst0063/_pdf/-char/enlarge eddy simulationone-equation subgrid scale modellow mach number flowschannelnaca0012 airfoil |
| spellingShingle | Changhwa HAN Takeo KAJISHIMA Large eddy simulation of weakly compressible turbulent flows around an airfoil Journal of Fluid Science and Technology large eddy simulation one-equation subgrid scale model low mach number flows channel naca0012 airfoil |
| title | Large eddy simulation of weakly compressible turbulent flows around an airfoil |
| title_full | Large eddy simulation of weakly compressible turbulent flows around an airfoil |
| title_fullStr | Large eddy simulation of weakly compressible turbulent flows around an airfoil |
| title_full_unstemmed | Large eddy simulation of weakly compressible turbulent flows around an airfoil |
| title_short | Large eddy simulation of weakly compressible turbulent flows around an airfoil |
| title_sort | large eddy simulation of weakly compressible turbulent flows around an airfoil |
| topic | large eddy simulation one-equation subgrid scale model low mach number flows channel naca0012 airfoil |
| url | https://www.jstage.jst.go.jp/article/jfst/9/4/9_2014jfst0063/_pdf/-char/en |
| work_keys_str_mv | AT changhwahan largeeddysimulationofweaklycompressibleturbulentflowsaroundanairfoil AT takeokajishima largeeddysimulationofweaklycompressibleturbulentflowsaroundanairfoil |