Welcome to our laboratory
Our main target is to develop the leading technology in computational science of fluid flow (solid-gas-liquid multiphase flow) by using the particle method for predicting flood flows due to a tsunami, a storm surge and an extremely heavy rain, and for improving water quality to preserve waterfront environment (e.g. aeration and sand capping on underwater mud). In addition, development of the Lagrangian simulator of crowded people, similar to the particle method, is being conducted for promoting a crowd refuge planning in various disasters.
We aim for establishment of the methodology of computational science and engineering, to describe various phenomena in civil engineering by a fluid/granular-material analogy.
Hitoshi Gotoh, Professor
[Top position in Most Cited Applied Ocean Research Articles]
Our publication: A higher order Laplacian model for enhancement and stabilization of pressure calculation by the MPS method (Applied Ocean Research, Volume 32, Issue 1, February 2010) has been listed in the top position in the Most Cited Applied Ocean Research Articles(as of January, 2015). Another our publication：A 3D higher order Laplacian model for enhancement and stabilization of pressure calculation in 3D MPS-based simulations (Applied Ocean Research, Volume 37, Issue 1, August 2012) is also ranked at the 14th position in the Most Cited Applied Ocean Research Articles(as of January, 2015).
[2nd position in Top 25 Hottest Article(Applied Ocean Research)]
In the annual download ranking Top 25 Hottest Articles (Applied Ocean Research), January to December 2014 full year, our joint publication with PARI (Port and Airport Research Institute) : On enhancement of Incompressible SPH method for simulation of violent sloshing flows (Applied Ocean Research, Volume 46, 2014) listed in the 2nd position.
[Technical book “Computational Wave Dynamics” has been released.]
echnical book “Computational Wave Dynamics” has been released from World Scientific Publishing Co(June 7, 2013). From our research groupe, Gotoh serves as one of the editors and Harada serves as one of the authors of this book.
Computational Wave Dynamics
by Hitoshi Gotoh, Akio Okayasu and Yasunori Watanabe
234pp, ISBN: 978-981-4449-70-0, Hardcover, US$54
[Special Page] Particle Method Benchmark
Special page named “Particle Method Benchmark” provides various benchmark tests of violent flows simulated by our high-performance particle methods.
As a small introduction to our laboratory, keywords are shown as follows:
As the Chair of Coastal Engineering at Kyoto University, our laboratory was originally founded in 1967 (see the page of “History”). The coastal engineering is a field dealing with disaster prevention, environmental preservation and human activities at a coast. We have worked on a wide theme from the coastal disaster prevention from a tsunami and a high tide, to the coastal environmental problems such as the ecosystem changes of an artificial beach. We also have contributed to a proposal and the advice for the coast management measures in the technical advisory committees of the national and the local governments.
Although the coastal engineering is one of the most important research fields for us, we approach various research fields, such as a protection against flood disasters in a river basin, a technology for preservation of water environment and so on, by the advanced technology of computer simulation.
A particle method (SPH method and MPS method) is mainly investigated in our laboratory. Although a violent flow with whitecaps and splash, such as a wave breaking at a coast or a hydraulic jump in a river, was difficult to be simulated by the conventional numerical models of fluid, a simulation of a violent flow is enabled by a particle method, which is the Lagrangian solver of the equation of motion of fluid.
Development of Frontier Technology of Fluid Computation
Activities of our laboratory are not limited to applications of existing particle methods to various hydraulic phenomena. In our laboratory, a basic study of the calculation principle, which can be applied to all related fields of fluid science and engineering, is performed. SPS-Turbulence Model for turbulence calculations of the particle methods is a technique that is developed firstly by our laboratory members. Accurate particle methods (CISPH-HS method, CMPS-HS method, etc), which have been developed in our laboratory, have been published on international academic journals registered with ISI Web of Science of THOMSON-REUTERS. Our accurate particle methods have been referred not only in construction engineering but also in many research fields of fluid science and engineering. Publications on this subject won a higher rank (Top five) for the plural periods in the download ranking of the Science Direct “Top 25 Hottest Articles (Coastal Engineering and Applied Ocean Research )”.
- Corrected Incompressible SPH method for accurate water-surface tracking in breaking waves(Coastal Engineering, Volume 55, Issue 3, March 2008)：2nd rank in 2011, 2012 and 2013 on Most Cited Coastal Engineering Articles.
- Modified Moving Particle Semi-implicit methods for the prediction of 2D wave impact pressure (Coastal Engineering, Volume 56, Issue 4, April 2009)：5th rank in 2011, 4th rank in 2012 and 2013, 2nd rank in 2014 on Most Cited Coastal Engineering Articles.
- Enhanced predictions of wave impact pressure by improved Incompressible SPH methods (Applied Ocean Research, Volume 31, Issue 2, April 2009): 2nd rank in 2013, top rank in 2014 on Most Cited Applied Ocean Research Articles.
- A higher order Laplacian model for enhancement and stabilization of pressure calculation by the MPS method (Applied Ocean Research, Volume 32, Issue 1, February 2010): 6th rank in 2013, 3rd rank in 2014, top rank in 2015 on Most Cited Applied Ocean Research Articles.
These articles were listed on the download ranking of Science Direct, Top 25 Hottest Articles. Especially, the following articles are listed in the annual download ranking.
- The top rank in Top 25 Hottest Articles (Applied Ocean Research) in the Oct. 2009- Sep. 2010 Academic Year：Enhanced predictions of wave impact pressure by improved Incompressible SPH methods (Applied Ocean Research, Volume 31, Issue 2, April 2009)
- The 2nd rank in Top 25 Hottest Articles (Applied Ocean Research) in January to December 2014 full year：On enhancement of Incompressible SPH method for simulation of violent sloshing flows (Applied Ocean Research, Volume 46, 2014)
In addition, the following articles were listed the top of the download rankings.
- GPU-acceleration for Moving Particle Semi-Implicit Method (Computers and Fluids, Volume 51, Issue 1, December 2011) on Most Read Computers & Fluids Articles (as of December, 2011)
- On enhancement of Incompressible SPH method for simulation of violent sloshing flows (Applied Ocean Research, Volume 46, 2014) on Most Downloaded Applied Ocean Research Articles (as of July, 2014)
U.S. Patent, Patent No.8521466
The patent entitled as follows has been granted by the United States. “METHOD AND DEVICE FOR DETERMINING INTERFACE PARTICLE USED IN PARTICLE METHOD AND PROGRAM FOR DETERMINING INTERFACE PARTICLE”
Link to patent No.8521466 in USPTO(United States Patent and Trademark Office). From Japan and the People's Republic of China, the patents with the same contents have been also granted.
Multi-physics by Particle Method
The target of the particle method is not limited to a fluid. The particle method is a general model of continuum, which can integrally describe an elastic body, a plastic body and a fluid. Large deformation phenomena that brought about difficulties in application of conventional technique, such as the FEM, can be analyzed by a particle method. The multi-physics that unify various phenomena in three major dynamics related to construction engineering, such as structural mechanics, soil mechanics and hydrodynamics, is possible. In our laboratory, the hybrid model of elasto-plastic body and fluid based on the particle method has been developed as a tool of interface fields between soil mechanics and hydrodynamics. This model can be applied to the prediction of a river-bank destruction due to a flood for urban disaster prevention.
Crowd Dynamics Model
If a person is regarded as a single particle, a crowd is a granular body with gathering particles. Auto traffic and the pedestrian crowd in urban areas can be interpreted based on the physics of a granular body. But because a person acts actively based on self-acquired information, the mathematical model of an active behavior is necessary. In our laboratory, the crowd behavior simulator CBS has been developed. CBS has been applied to disaster evacuations (CBS-DE), such as evacuations at the time of floods and tsunamis, evacuations at the time of the fire from the underground spaces (shopping center, a tunnel, etc.). CBS can be also applied to a pedestrian space design, such as a railway station square. Developing computational hardware will make an over-100,000 people scale calculation possible in near future. Construction of a Virtual City as the tool of the social experiment in a virtual space will be realized.
Because over 1000,000 particles are tracked in the calculation of particle methods, a device that helps intuitive understanding of calculation results is indispensable. For example, in the numerical simulation of waves, a state as if we observe from a side of an experimental water tank is reproduced with CG. It is called Numerical Wave Flume. In addition, in crowd behavior simulator CBS, the model of a person with moving hands and feet is drawn. The CG and the dynamic image as post-processing of the simulation is indispensable for the interpretation of heavy computations performed in our laboratory.