Roughness Effect on the Flow Past Axisymmetric Bodies at High Incidence
The flow at low Mach numbers and high angles of attack over axisymmetric configurations is not symmetric. The mechanism that triggers the asymmetry is a combination of a global (temporal) instability and a convective (spatial) instability. This latter instability is caused by roughness and other geo...
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| Format: | Article |
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MDPI AG
2022-10-01
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| Series: | Aerospace |
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| Online Access: | https://www.mdpi.com/2226-4310/9/11/668 |
| _version_ | 1797469540031922176 |
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| author | José Jiménez-Varona Gabriel Liaño José L. Castillo Pedro L. García-Ybarra |
| author_facet | José Jiménez-Varona Gabriel Liaño José L. Castillo Pedro L. García-Ybarra |
| author_sort | José Jiménez-Varona |
| collection | DOAJ |
| description | The flow at low Mach numbers and high angles of attack over axisymmetric configurations is not symmetric. The mechanism that triggers the asymmetry is a combination of a global (temporal) instability and a convective (spatial) instability. This latter instability is caused by roughness and other geometrical imperfections, which lead to roll angle dependent forces. The flow at these conditions has a complex vortex sheet structure, with two or three different flow regions. An accurate simulation by means of Computational Flow Dynamics (CFD) is thus very challenging, and many researchers have therefore employed Large Eddy Simulation (LES) codes. This study demonstrates that Unsteady Reynolds Averaged Navier-Stokes (URANS) methods are a suitable alternative, if Scale Adaptive Simulation (SAS) is used. This method is capable of capturing the main flow features, provided that fine meshes, which achieve geometrical similarity between the meshed geometry and the real object, and small-time steps are used. It is also demonstrated that, by using URANS methods in combination with SAS, strong differences in the global and local forces depending on the surface roughness of the model are obtained, a result which coincides with several wind tunnel tests. |
| first_indexed | 2024-03-09T19:21:50Z |
| format | Article |
| id | doaj.art-3fa3a7f4c0d845afa07e6618eef9b3da |
| institution | Directory Open Access Journal |
| issn | 2226-4310 |
| language | English |
| last_indexed | 2024-03-09T19:21:50Z |
| publishDate | 2022-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Aerospace |
| spelling | doaj.art-3fa3a7f4c0d845afa07e6618eef9b3da2023-11-24T03:15:31ZengMDPI AGAerospace2226-43102022-10-0191166810.3390/aerospace9110668Roughness Effect on the Flow Past Axisymmetric Bodies at High IncidenceJosé Jiménez-Varona0Gabriel Liaño1José L. Castillo2Pedro L. García-Ybarra3Aerodynamics Lab, Flight Physics Department, INTA, Crtra, Ajalvir km 4,5, Torrejón de Ardoz, 28850 Madrid, SpainAerodynamics Lab, Flight Physics Department, INTA, Crtra, Ajalvir km 4,5, Torrejón de Ardoz, 28850 Madrid, SpainFaculty of Sciences, Universidad Nacional de Educación a Distancia, Avda. Esparta s/n, Las Rozas, 28232 Madrid, SpainFaculty of Sciences, Universidad Nacional de Educación a Distancia, Avda. Esparta s/n, Las Rozas, 28232 Madrid, SpainThe flow at low Mach numbers and high angles of attack over axisymmetric configurations is not symmetric. The mechanism that triggers the asymmetry is a combination of a global (temporal) instability and a convective (spatial) instability. This latter instability is caused by roughness and other geometrical imperfections, which lead to roll angle dependent forces. The flow at these conditions has a complex vortex sheet structure, with two or three different flow regions. An accurate simulation by means of Computational Flow Dynamics (CFD) is thus very challenging, and many researchers have therefore employed Large Eddy Simulation (LES) codes. This study demonstrates that Unsteady Reynolds Averaged Navier-Stokes (URANS) methods are a suitable alternative, if Scale Adaptive Simulation (SAS) is used. This method is capable of capturing the main flow features, provided that fine meshes, which achieve geometrical similarity between the meshed geometry and the real object, and small-time steps are used. It is also demonstrated that, by using URANS methods in combination with SAS, strong differences in the global and local forces depending on the surface roughness of the model are obtained, a result which coincides with several wind tunnel tests.https://www.mdpi.com/2226-4310/9/11/668roughnessvortex sheddingasymmetric flowCFDgridsscale adaptive simulation |
| spellingShingle | José Jiménez-Varona Gabriel Liaño José L. Castillo Pedro L. García-Ybarra Roughness Effect on the Flow Past Axisymmetric Bodies at High Incidence Aerospace roughness vortex shedding asymmetric flow CFD grids scale adaptive simulation |
| title | Roughness Effect on the Flow Past Axisymmetric Bodies at High Incidence |
| title_full | Roughness Effect on the Flow Past Axisymmetric Bodies at High Incidence |
| title_fullStr | Roughness Effect on the Flow Past Axisymmetric Bodies at High Incidence |
| title_full_unstemmed | Roughness Effect on the Flow Past Axisymmetric Bodies at High Incidence |
| title_short | Roughness Effect on the Flow Past Axisymmetric Bodies at High Incidence |
| title_sort | roughness effect on the flow past axisymmetric bodies at high incidence |
| topic | roughness vortex shedding asymmetric flow CFD grids scale adaptive simulation |
| url | https://www.mdpi.com/2226-4310/9/11/668 |
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