2019 Fiscal Year Research-status Report
Development of a next-generation IGA-BEM based on T-splines to investigate the performance of complex-shaped wave energy devices undergoing strong mutual interactions in large arrays
| Project/Area Number |
18K13939
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| Research Institution | Kyushu University |
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Principal Investigator |
劉 盈溢 九州大学, 応用力学研究所, 助教 (30799127)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Keywords | Enhanced-Endo’s approach / multiple scattering |
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| Outline of Annual Research Achievements |
Wave energy is abundant along the coastal line and in the deep-water area further offshore. Since most of the coastal and offshore areas are of intermediate water depths, it is important to develop an efficient algorithm for these cases. The numerical computation is therefore further improved by elaborating the algorithm of free-surface Green’s function in finite-depth water. Endo’s integration approach is enhanced by removing the weired points at which strong singularities are encountered. The Enhanced-Endo’s approach is later further facilitated in combination of the eigenfunction expansion series. The computation speed is improved substantially in the region of small parameters R/h. Interactions between multiple floating structures are considered by applying a newly-developed multiple scattering approach. The new approach is different from the tradiational ones basing on the source formulation. The method of Goo and Yoshida (1990) is extended by applying the mixed source/dipole distribution in evaluation of the matrix elements. A formulation is developed similar to the study of McNatt et al. (2015), however, including the evanescent terms as well. Validation is underway with the other existing methods.
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| Current Status of Research Progress |
Current Status of Research Progress
3: Progress in research has been slightly delayed.
Reason
While the developments of the numerical algorithm of free-surface Green’s function and the multiple scattering approach is smoothly undertaken, the development of T-spline based IGA concept encounter some obstacles. One is the removal of irregular frequencies, which is fairly different from that of a constant panel method, and another is the geometrical processing. However, the so-far developed solver based on panel method and multiple scattering approach will still be able to simulate large arrays of wave energy converters, provided with the proper validations done. The numerical algorithm of Enhanced-Endo’s approach has been presented in the JASNAOE spring conference and a corresponding journal paper has been accepted by Ocean Engineering.
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| Strategy for Future Research Activity |
The enhanced multi-body hydrodynamic solver based on the multiple scattering approach is going to be extensively validated for the application to large arrays of wave energy converters.
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| Causes of Carryover |
The planned attendance of the international conference EWTEC 2019 was cancelled due to the change of schedule. The purchase of the commercial software WAMIT was also moved to the next year. The rest of funding will be used in the next year for attending international conferences and purchasing the software.
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