著者

Tomohiro Takaki Shinji Sakane Takayuki Aoki

出版者

The Iron and Steel Institute of Japan

雑誌

ISIJ International (ISSN:09151559)

巻号頁・発行日

vol.63, no.1, pp.83-90, 2023-01-15 (Released:2023-01-21)

参考文献数

50

被引用文献数

3

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Numerical study on the effect of liquid flow on three-dimensional dendrite growth is still a challenging topic. Herein, high-performance phase–field lattice Boltzmann (PF-LB) simulations were performed to investigate the effect of natural convection on dendrite morphology and the possibility for causing fragmentation. Parallel computing in multiple graphics processing units (GPUs) with dynamic load balancing for the block-structured adaptive mesh refinement (AMR) scheme (parallel-GPU AMR) was applied to the PF-LB simulations as a high-performance computing tool in a GPU supercomputer. Parallel-GPU AMR PF-LB simulations showed that the growth of dendrites with natural convection in two and three dimensions were quite different. The dendrite tip velocity increased in the following order: upward buoyancy, no gravity, and downward buoyancy. Downward and upward buoyancy enhanced and restricted the growth of the secondary arms, respectively. The root size of the secondary arms growing from the bottom was drastically affected by the flow direction. However, the dendrite fragmentations were not observed in the present simulations.

著者

Tomohiro TAKAKI Kazuya NAKAGAWA Yusuke MORITA Eiji NAKAMACHI

出版者

一般社団法人日本機械学会

雑誌

Mechanical Engineering Journal (ISSN:21879745)

巻号頁・発行日

vol.2, no.3, pp.15-00063-15-00063, 2015 (Released:2015-06-15)

参考文献数

61

被引用文献数

1 6

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In this study, we applied a modified Kobayashi-Warren-Carter (KWC) phase-field model to the neurite growth process. To confirm the applicability of this model, we observed axonal extension of PC-12D cells cultured with nerve growth factor (NGF). Based on our observations, we defined three stages of nerve cell axonal extension: neurite generation, neurite contraction, and axon extension. We further determined the parameters in the phase-field equations to express the three extension stages. Finally, our results show that the modified KWC phase-field model reasonably expresses the morphologies of nerve cells and predicts the three stages of nerve cell axonal extension. Although, we employed the binary alloy solidification model as a sample model in the present phase-field simulations, this work will be extensible to relatively more realistic models for nerve cell growth.

著者

Tomohiro TAKAKI Kazuya NAKAGAWA Yusuke MORITA Eiji NAKAMACHI

出版者

一般社団法人日本機械学会

雑誌

Mechanical Engineering Journal (ISSN:21879745)

巻号頁・発行日

pp.15-00063, (Released:2015-05-22)

参考文献数

61

被引用文献数

1 6

---

In this study, we applied a modified Kobayashi-Warren-Carter (KWC) phase-field model to the neurite growth process. To confirm the applicability of this model, we observed axonal extension of PC-12D cells cultured with nerve growth factor (NGF). Based on our observations, we defined three stages of nerve cell axonal extension: neurite generation, neurite contraction, and axon extension. We further determined the parameters in the phase-field equations to express the three extension stages. Finally, our results show that the modified KWC phase-field model reasonably expresses the morphologies of nerve cells and predicts the three stages of nerve cell axonal extension. Although, we employed the binary alloy solidification model as a sample model in the present phase-field simulations, this work will be extensible to relatively more realistic models for nerve cell growth.

著者

Tomohiro Takaki

出版者

一般社団法人 日本鉄鋼協会

雑誌

ISIJ International (ISSN:09151559)

巻号頁・発行日

vol.54, no.2, pp.437-444, 2014-02-15 (Released:2014-03-11)

参考文献数

200

被引用文献数

18 162 32

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The phase-field method has recently emerged as the most powerful computational tool for simulating complicated dendrite growth. However, these simulations are still limited to two-dimensional or small three-dimensional spaces; therefore, to realistic and practical dendritic structures, it is crucial to develop a large-scale phase-field simulation technique. This review discusses the phase-field modeling and simulations of dendrite growth from the fundamental model to cutting-edge very-large-scale simulations. First, phase-field models for the dendrite growth of pure materials and binary alloys and their histories are summarized. Then, models and studies of interface anisotropy, polycrystalline solidification, and solidification with convection, which are very important in dendritic solidification, are reviewed. Finally, by introducing very-large-scale phase-field simulations performed recently using a graphics processing unit supercomputer, the power, potential and importance of the very-large-scale phase-field simulation are emphasized.