An Entropy-Assisted Shielding Function in DDES Formulation for the SST Turbulence Model
The intent of shielding functions in delayed detached-eddy simulation methods (DDES) is to preserve the wall boundary layers as Reynolds-averaged Navier–Strokes (RANS) mode, avoiding possible modeled stress depletion (MSD) or even unphysical separation due to grid refinement. An entropy function fs...
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MDPI AG
2017-02-01
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| Series: | Entropy |
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| Online Access: | http://www.mdpi.com/1099-4300/19/3/93 |
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| author | Ling Zhou Rui Zhao Xiao-Pan Shi |
| author_facet | Ling Zhou Rui Zhao Xiao-Pan Shi |
| author_sort | Ling Zhou |
| collection | DOAJ |
| description | The intent of shielding functions in delayed detached-eddy simulation methods (DDES) is to preserve the wall boundary layers as Reynolds-averaged Navier–Strokes (RANS) mode, avoiding possible modeled stress depletion (MSD) or even unphysical separation due to grid refinement. An entropy function fs is introduced to construct a DDES formulation for the k-ω shear stress transport (SST) model, whose performance is extensively examined on a range of attached and separated flows (flat-plate flow, circular cylinder flow, and supersonic cavity-ramp flow). Two more forms of shielding functions are also included for comparison: one that uses the blending function F2 of SST, the other which adopts the recalibrated shielding function fd_cor of the DDES version based on the Spalart-Allmaras (SA) model. In general, all of the shielding functions do not impair the vortex in fully separated flows. However, for flows including attached boundary layer, both F2 and the recalibrated fd_cor are found to be too conservative to resolve the unsteady flow content. On the other side, fs is proposed on the theory of energy dissipation and independent on from any particular turbulence model, showing the generic priority by properly balancing the need of reserving the RANS modeled regions for wall boundary layers and generating the unsteady turbulent structures in detached areas. |
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| institution | Directory Open Access Journal |
| issn | 1099-4300 |
| language | English |
| last_indexed | 2024-12-10T06:57:22Z |
| publishDate | 2017-02-01 |
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| series | Entropy |
| spelling | doaj.art-29c94e6f6b3f4df39c4cd1342fcc70532022-12-22T01:58:25ZengMDPI AGEntropy1099-43002017-02-011939310.3390/e19030093e19030093An Entropy-Assisted Shielding Function in DDES Formulation for the SST Turbulence ModelLing Zhou0Rui Zhao1Xiao-Pan Shi2School of Energy and Power Engineering, Huazhong University of Science & Technology, Wuhan 430074, ChinaSchool of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081, ChinaSchool of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081, ChinaThe intent of shielding functions in delayed detached-eddy simulation methods (DDES) is to preserve the wall boundary layers as Reynolds-averaged Navier–Strokes (RANS) mode, avoiding possible modeled stress depletion (MSD) or even unphysical separation due to grid refinement. An entropy function fs is introduced to construct a DDES formulation for the k-ω shear stress transport (SST) model, whose performance is extensively examined on a range of attached and separated flows (flat-plate flow, circular cylinder flow, and supersonic cavity-ramp flow). Two more forms of shielding functions are also included for comparison: one that uses the blending function F2 of SST, the other which adopts the recalibrated shielding function fd_cor of the DDES version based on the Spalart-Allmaras (SA) model. In general, all of the shielding functions do not impair the vortex in fully separated flows. However, for flows including attached boundary layer, both F2 and the recalibrated fd_cor are found to be too conservative to resolve the unsteady flow content. On the other side, fs is proposed on the theory of energy dissipation and independent on from any particular turbulence model, showing the generic priority by properly balancing the need of reserving the RANS modeled regions for wall boundary layers and generating the unsteady turbulent structures in detached areas.http://www.mdpi.com/1099-4300/19/3/93entropyshielding functiondelayed detached-eddy simulation |
| spellingShingle | Ling Zhou Rui Zhao Xiao-Pan Shi An Entropy-Assisted Shielding Function in DDES Formulation for the SST Turbulence Model Entropy entropy shielding function delayed detached-eddy simulation |
| title | An Entropy-Assisted Shielding Function in DDES Formulation for the SST Turbulence Model |
| title_full | An Entropy-Assisted Shielding Function in DDES Formulation for the SST Turbulence Model |
| title_fullStr | An Entropy-Assisted Shielding Function in DDES Formulation for the SST Turbulence Model |
| title_full_unstemmed | An Entropy-Assisted Shielding Function in DDES Formulation for the SST Turbulence Model |
| title_short | An Entropy-Assisted Shielding Function in DDES Formulation for the SST Turbulence Model |
| title_sort | entropy assisted shielding function in ddes formulation for the sst turbulence model |
| topic | entropy shielding function delayed detached-eddy simulation |
| url | http://www.mdpi.com/1099-4300/19/3/93 |
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