Direct numerical simulation of the turbulent flow around a Flettner rotor
Abstract The three-dimensional turbulent flow around a Flettner rotor, i.e. an engine-driven rotating cylinder in an atmospheric boundary layer, is studied via direct numerical simulations (DNS) for three different rotation speeds ( $$\alpha$$ α ). This technology offers a sustainable alternative ma...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2024-02-01
|
| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-024-53194-x |
| _version_ | 1827327626061021184 |
|---|---|
| author | Daniele Massaro Martin Karp Niclas Jansson Stefano Markidis Philipp Schlatter |
| author_facet | Daniele Massaro Martin Karp Niclas Jansson Stefano Markidis Philipp Schlatter |
| author_sort | Daniele Massaro |
| collection | DOAJ |
| description | Abstract The three-dimensional turbulent flow around a Flettner rotor, i.e. an engine-driven rotating cylinder in an atmospheric boundary layer, is studied via direct numerical simulations (DNS) for three different rotation speeds ( $$\alpha$$ α ). This technology offers a sustainable alternative mainly for marine propulsion, underscoring the critical importance of comprehending the characteristics of such flow. In this study, we evaluate the aerodynamic loads produced by the rotor of height h, with a specific focus on the changes in lift and drag force along the vertical axis of the cylinder. Correspondingly, we observe that vortex shedding is inhibited at the highest $$\alpha$$ α values investigated. However, in the case of intermediate $$\alpha$$ α , vortices continue to be shed in the upper section of the cylinder ( $$y/h>0.3$$ y / h > 0.3 ). As the cylinder begins to rotate, a large-scale motion becomes apparent on the high-pressure side, close to the bottom wall. We offer both a qualitative and quantitative description of this motion, outlining its impact on the wake deflection. This finding is significant as it influences the rotor wake to an extent of approximately one hundred diameters downstream. In practical applications, this phenomenon could influence the performance of subsequent boats and have an impact on the cylinder drag, affecting its fuel consumption. This fundamental study, which investigates a limited yet significant (for DNS) Reynolds number and explores various spinning ratios, provides valuable insights into the complex flow around a Flettner rotor. The simulations were performed using a modern GPU-based spectral element method, leveraging the power of modern supercomputers towards fundamental engineering problems. |
| first_indexed | 2024-03-07T15:04:00Z |
| format | Article |
| id | doaj.art-1e00393307f44eb8a4538d001ffcaf0a |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-03-07T15:04:00Z |
| publishDate | 2024-02-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-1e00393307f44eb8a4538d001ffcaf0a2024-03-05T18:57:29ZengNature PortfolioScientific Reports2045-23222024-02-0114111410.1038/s41598-024-53194-xDirect numerical simulation of the turbulent flow around a Flettner rotorDaniele Massaro0Martin Karp1Niclas Jansson2Stefano Markidis3Philipp Schlatter4SimEx/FLOW, Engineering Mechanics, KTH Royal Institute of TechnologyDivision of Computational Science and Technology, EECS, KTH Royal Institute of TechnologyPDC Centre for High Performance Computing, EECS, KTH Royal Institute of TechnologyDivision of Computational Science and Technology, EECS, KTH Royal Institute of TechnologySimEx/FLOW, Engineering Mechanics, KTH Royal Institute of TechnologyAbstract The three-dimensional turbulent flow around a Flettner rotor, i.e. an engine-driven rotating cylinder in an atmospheric boundary layer, is studied via direct numerical simulations (DNS) for three different rotation speeds ( $$\alpha$$ α ). This technology offers a sustainable alternative mainly for marine propulsion, underscoring the critical importance of comprehending the characteristics of such flow. In this study, we evaluate the aerodynamic loads produced by the rotor of height h, with a specific focus on the changes in lift and drag force along the vertical axis of the cylinder. Correspondingly, we observe that vortex shedding is inhibited at the highest $$\alpha$$ α values investigated. However, in the case of intermediate $$\alpha$$ α , vortices continue to be shed in the upper section of the cylinder ( $$y/h>0.3$$ y / h > 0.3 ). As the cylinder begins to rotate, a large-scale motion becomes apparent on the high-pressure side, close to the bottom wall. We offer both a qualitative and quantitative description of this motion, outlining its impact on the wake deflection. This finding is significant as it influences the rotor wake to an extent of approximately one hundred diameters downstream. In practical applications, this phenomenon could influence the performance of subsequent boats and have an impact on the cylinder drag, affecting its fuel consumption. This fundamental study, which investigates a limited yet significant (for DNS) Reynolds number and explores various spinning ratios, provides valuable insights into the complex flow around a Flettner rotor. The simulations were performed using a modern GPU-based spectral element method, leveraging the power of modern supercomputers towards fundamental engineering problems.https://doi.org/10.1038/s41598-024-53194-x |
| spellingShingle | Daniele Massaro Martin Karp Niclas Jansson Stefano Markidis Philipp Schlatter Direct numerical simulation of the turbulent flow around a Flettner rotor Scientific Reports |
| title | Direct numerical simulation of the turbulent flow around a Flettner rotor |
| title_full | Direct numerical simulation of the turbulent flow around a Flettner rotor |
| title_fullStr | Direct numerical simulation of the turbulent flow around a Flettner rotor |
| title_full_unstemmed | Direct numerical simulation of the turbulent flow around a Flettner rotor |
| title_short | Direct numerical simulation of the turbulent flow around a Flettner rotor |
| title_sort | direct numerical simulation of the turbulent flow around a flettner rotor |
| url | https://doi.org/10.1038/s41598-024-53194-x |
| work_keys_str_mv | AT danielemassaro directnumericalsimulationoftheturbulentflowaroundaflettnerrotor AT martinkarp directnumericalsimulationoftheturbulentflowaroundaflettnerrotor AT niclasjansson directnumericalsimulationoftheturbulentflowaroundaflettnerrotor AT stefanomarkidis directnumericalsimulationoftheturbulentflowaroundaflettnerrotor AT philippschlatter directnumericalsimulationoftheturbulentflowaroundaflettnerrotor |