PROBING INTO THE EFFECTS OF CAVITATION ON HYDRODYNAMIC CHARACTERISTICS OF SURFACE PIERCING PROPELLERS THROUGH NUMERICAL MODELING OF OBLIQUE WATER ENTRY OF A THIN WEDGE
The current paper investigates flow around a blade section of a surface piercing hydrofoil. To this end, a thin wedge section is numerically modelled through an oblique water entry. The flow is numerically studied using a multiphase approach. The proposed numerical approach is validated in two steps...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Faculty of Mechanical Engineering and Naval Architecture
2018-01-01
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| Series: | Brodogradnja |
| Online Access: | http://hrcak.srce.hr/file/280368 |
| _version_ | 1811193356294815744 |
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| author | Nasrin Javanmardi Parviz Ghadimi Sasan Tavakoli |
| author_facet | Nasrin Javanmardi Parviz Ghadimi Sasan Tavakoli |
| author_sort | Nasrin Javanmardi |
| collection | DOAJ |
| description | The current paper investigates flow around a blade section of a surface piercing hydrofoil. To this end, a thin wedge section is numerically modelled through an oblique water entry. The flow is numerically studied using a multiphase approach. The proposed numerical approach is validated in two steps. First, pressure and free surface around a wedge entering water are simulated and compared against previously published analytical results. Subsequently, cavitation phenomenon around a submerged supercavitating hydrofoil is modelled and analyzed. It is observed that cavity length, pressure, and lift force are accurately predicted. Subsequently, the main problem has been studied for two different cavitation numbers for a range of advanced ratios equivalent to fully, transition and partially ventilated conditions in order to investigate the effect of ambient pressure on hydrodynamics of the water entry of the foil. The numerical findings reveal that, when the cavitation number decreases, the start of transition mode is postponed and this mode is expanded for the larger range of velocity ratios. This implies that fully ventilated velocity ratio modes are expanded, too. However, in the transition mode, the cavitation number plays an essential role and may lead to a decrease in the pressure difference across the surface piercing hydrofoil which yields a decrease in the resultant force. |
| first_indexed | 2024-04-12T00:07:00Z |
| format | Article |
| id | doaj.art-3feaa477090a410dbe6c500244873763 |
| institution | Directory Open Access Journal |
| issn | 0007-215X 1845-5859 |
| language | English |
| last_indexed | 2024-04-12T00:07:00Z |
| publishDate | 2018-01-01 |
| publisher | Faculty of Mechanical Engineering and Naval Architecture |
| record_format | Article |
| series | Brodogradnja |
| spelling | doaj.art-3feaa477090a410dbe6c5002448737632022-12-22T03:56:04ZengFaculty of Mechanical Engineering and Naval ArchitectureBrodogradnja0007-215X1845-58592018-01-01691151168190223PROBING INTO THE EFFECTS OF CAVITATION ON HYDRODYNAMIC CHARACTERISTICS OF SURFACE PIERCING PROPELLERS THROUGH NUMERICAL MODELING OF OBLIQUE WATER ENTRY OF A THIN WEDGENasrin Javanmardi0Parviz Ghadimi1Sasan Tavakoli2Dept. of Marine Technology, Amirkabir University of Technology, Tehran, IranDept. of Marine Technology, Amirkabir University of Technology, Tehran, IranDept. of Marine Technology, Amirkabir University of Technology, Tehran, IranThe current paper investigates flow around a blade section of a surface piercing hydrofoil. To this end, a thin wedge section is numerically modelled through an oblique water entry. The flow is numerically studied using a multiphase approach. The proposed numerical approach is validated in two steps. First, pressure and free surface around a wedge entering water are simulated and compared against previously published analytical results. Subsequently, cavitation phenomenon around a submerged supercavitating hydrofoil is modelled and analyzed. It is observed that cavity length, pressure, and lift force are accurately predicted. Subsequently, the main problem has been studied for two different cavitation numbers for a range of advanced ratios equivalent to fully, transition and partially ventilated conditions in order to investigate the effect of ambient pressure on hydrodynamics of the water entry of the foil. The numerical findings reveal that, when the cavitation number decreases, the start of transition mode is postponed and this mode is expanded for the larger range of velocity ratios. This implies that fully ventilated velocity ratio modes are expanded, too. However, in the transition mode, the cavitation number plays an essential role and may lead to a decrease in the pressure difference across the surface piercing hydrofoil which yields a decrease in the resultant force.http://hrcak.srce.hr/file/280368 |
| spellingShingle | Nasrin Javanmardi Parviz Ghadimi Sasan Tavakoli PROBING INTO THE EFFECTS OF CAVITATION ON HYDRODYNAMIC CHARACTERISTICS OF SURFACE PIERCING PROPELLERS THROUGH NUMERICAL MODELING OF OBLIQUE WATER ENTRY OF A THIN WEDGE Brodogradnja |
| title | PROBING INTO THE EFFECTS OF CAVITATION ON HYDRODYNAMIC CHARACTERISTICS OF SURFACE PIERCING PROPELLERS THROUGH NUMERICAL MODELING OF OBLIQUE WATER ENTRY OF A THIN WEDGE |
| title_full | PROBING INTO THE EFFECTS OF CAVITATION ON HYDRODYNAMIC CHARACTERISTICS OF SURFACE PIERCING PROPELLERS THROUGH NUMERICAL MODELING OF OBLIQUE WATER ENTRY OF A THIN WEDGE |
| title_fullStr | PROBING INTO THE EFFECTS OF CAVITATION ON HYDRODYNAMIC CHARACTERISTICS OF SURFACE PIERCING PROPELLERS THROUGH NUMERICAL MODELING OF OBLIQUE WATER ENTRY OF A THIN WEDGE |
| title_full_unstemmed | PROBING INTO THE EFFECTS OF CAVITATION ON HYDRODYNAMIC CHARACTERISTICS OF SURFACE PIERCING PROPELLERS THROUGH NUMERICAL MODELING OF OBLIQUE WATER ENTRY OF A THIN WEDGE |
| title_short | PROBING INTO THE EFFECTS OF CAVITATION ON HYDRODYNAMIC CHARACTERISTICS OF SURFACE PIERCING PROPELLERS THROUGH NUMERICAL MODELING OF OBLIQUE WATER ENTRY OF A THIN WEDGE |
| title_sort | probing into the effects of cavitation on hydrodynamic characteristics of surface piercing propellers through numerical modeling of oblique water entry of a thin wedge |
| url | http://hrcak.srce.hr/file/280368 |
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