| 研究実績の概要 |
The final target of this research is to develop an advanced adaptive and multi-physics computational method for hydroelastic FSI (Fluid-Structure Interactions) encountered in ocean/coastal engineering. In this regard, for robust development of structure model, in particular, for reliable modelling of composite structures with material discontinuities, importance of development of variationally consistent structure model has been highlighted and a Hamiltonian SPH (HSPH) structure model has been developed and consistently coupled with projection SPH, or Incompressible SPH (ISPH) fluid model, resulting in ISPH-HSPH FSI solver [1]. The developed hydroelastic FSI solver has been shown to provide accurate results for a wide range of benchmark test cases including hydroelastic slamming of marine panels. Regarding the adaptivity of the solver, SPH-based multi-resolution schemes have been developed [2] and validated in several test cases including a violent fluid flow impact problem with an elastic plate. In addition, efforts have been devoted to extend the developed HSPH structure model to 3D as well as conducting careful reformulations and corresponding coding to treat anisotropic composite materials. In this regard a manuscript is under final stages of its preparation.
[1] Khayyer, A., Gotoh, H., Shimizu, Y., Nagashima, K., Applied Mathematical Modelling, 94,242-271, 2021.
[2] Khayyer, A., Gotoh, H., Shimizu, Y., Hattori, S., Ocean Engineering, 226, 108652, 2021.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
The targeted advancements for development of an adaptive multi-physics Fluid-Structure Interaction (FSI) solver have been achieved to a satisfactory level, as planned. An advanced, accurate ISPH-HSPH hydroelastic FSI solver has been developed with capability of reliably reproducing hydroelastic FSI corresponding to composite structures with large material discontinuities in both density and Young's modulus. The developed solver has been presented in an international journal article published in Applied Mathematical Modelling [1]. Regarding the adaptivity, SPH-based adaptive or multi-resolution schemes have been developed and validated. Corresponding schemes have been published in Ocean Engineering journal, which is a leading international journal in Ocean Engineering [2]. The multi-phase liquid-gas scheme has already been developed [3] and currently the main focus is on coherent, careful extension of ISPH-HSPH to 3D, along with conducting reformulations/coding corresponding to anisotropic composite structures. A manuscript regarding these two important developments (three-dimensionality, anisotropic composite materials), is in final stages of preparation and will be soon submitted to Applied Mathematical Modelling.
[3] Khayyer, A., Gotoh, H., Shimizu, Y., Computers & Fluids, 179, 356-371, 2019.
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| 今後の研究の推進方策 |
I. An important matter in scientific developments corresponds to rigorousness and coherence. Developments must be made coherently with rigorous step-by-step, comprehensive validations. In this regard, for developed ISPH-HSPH hydroelastic FSI solver, systematic validations have been conducted. Another important matter corresponds to Generality of the solver, i.e. applicability to a wide range of possible engineering problems in which three-dimensionality as well as material anisotropy may become of vital importance. Thus, the present efforts have been dedicated to extension of (Newtonian-Hamiltonian) ISPH-HSPH FSI solver to 3D along with robust handling of material anisotropy. For robust and reliable handling of anisotropic materials, careful reformulations on the basis of stress-strain responses must be made along with coherent, rigorous validations, first in 2D and then in 3D. Validations should be first made for the HSPH structure model and then for the corresponding FSI solver in reproducing hydroelastic FSI comprising composite structures with material anisotropy.
II. Followed by rigorous development of the 3D hydroelastic FSI comprising anisotropic/isotropic composite structures, inclusion of air will be coherently considered and the multi-phase air-water model will be precisely incorporated first in two-dimensions and then in three-dimensions. Validations need to be conducted scrupulously including test cases involving large structural deformations in a multi-physics air-water-structure system.
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| 次年度使用額が生じた理由 |
With respect to the fact that computationally expensive (in terms of both CPU time and required memory) simulations are to be carried out in 2021 for 3D multi-physics air-water-structure system comprising hydroelastic FSI solver, and with respect to the corresponding post-processing of numerical data which requires high performance computer systems as well as software and storage devices, the remaining amount of about 250,000 yen is considered to be merged with the fund granted for FY2021 to purchase a more capable computer system with high specifications including high memory and required post-processing software. A portion of the remaining fund will be also used for purchase of data storage devices such as SSDs.
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