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报告题目：Applications of Smoothed Particle Hydrodynamics (SPH) in some Sediment Transport Problems

报告人：Nhan Phan-Thien（National University of Singapore）

时间：2017年1月3日上午9:00

地点：船海楼15楼大会议室

主办单位：科学技术研究院

承办单位：船舶工程学院

报告人简介：

Academic/Professional Qualifications:

ØBE (1st Hons, University Medal) (1975), University of Sydney, Australia

ØPhD (1979), University of Sydney, Australia

ØFellow of the Australian Academy of Science (elected 1999)

ØFellow of the Asean Academy of Engineering and Technology (2016)

ØAssociate Editor, Physics of Fluids

Career History:

Ø2017-2019: Honorary Professor, School of Aerospace, Mechanical and Mechatronic Engineering, the University of Sydney, Australia

Ø2016-present: Head, Mechanical Engineering Department, NUS

Ø2011-present: Professor in Mechanical, Mechanical Engineering Department, NUS

Ø2007-2008: Adjunct Professor, Chemical & Material Engineering Department, University of California, Davis, USA

Ø2005-2011: Partners in NT Investments (five different LLC incorporated in California)

Ø2001-2004: Founding Chair in Bio Engineering, NUS

Ø2003 : Visiting Professor, Chemical Engineering Department, Stanford University

Ø2003-2004: Deputy Director, NUS Graduate School of Integrated Science and Engineering

Ø2001-2004: Deputy Director, Office of Life Science

Ø1991-2001: Personal Chair in Mechanical Engineering, Sydney University

Ø1989, 90, 92, 95: External Consultant, Los Alamos National Laboratory, New Mexico 87544, USA

ØMajor Prizes/Awards

Ø2003 Centenary Medal awarded by the Australian Governor General, for service to Australian society and science in Mechanical Engineering;

Ø2003 Silver Prize, HPC Quest, Blue Challenge by IBM and the Institute of High Performance Computing on entry Flow of Complex Fluids through Micro Channels;

Ø1997 Gordon Bell Prize, Price-Performance category, Computer Division IEEE;

Ø1997 Australian Society of Rheology Medal, awarded by the Australian Society of Rheology for distinguished contributions to Rheology;

Ø1982 Edgeworth David Medal, awarded by the Royal Society of New South Wales, for distinguished researches in science amongst younger workers in Applied Mechanics;

Ø1982 Senior Fulbright Scholar, California Institute of Technology;

Ø1975 University Medal.

报告简介:

Numerical simulations of the sediment dispersion problems, both in the near-field and the far-field are considered, using a particle-based method, the smoothed particle hydrodynamics (SPH) approach. The motivation comes from the need to provide an accurate assessment of the sediment dispersion resulted from technical activities involving an equipment deployed in the deep sea floor. In the near-field sediment disturbance problem (due to the motion of an equipment on the seabed), of several linear dimensions of the equipment, a reasonable rheological model for the sediment needs to be employed, in addition to a generally acceptable turbulent model. Here, for the rheological model, we adopt a yield-stress model due to Papanastasiou [1], which can be considered as a regularisation of the classical Bingham yield-stress fluid model. For a description of turbulent, different models are considered, including the k-ωSST model [2]. In the far-field sediment dispersion problem, of several kms length scale, the sediment/equipment interaction is replaced by a distribution of sediment generating source, which is convected and diffused with the underlined current. Correct and accepted boundary conditions for sediment deposition and re-suspension need to be incorporated [3]. In both cases, near- and far-field, the diffusion (due to turbulent or otherwise) is anisotropic, and methods dealing with anisotropic diffusion must be investigated and verified [4]. In this talk, we describe the SPH method in some details, especially in its ability to handle anisotropic diffusion problems; then the near- and far-field problems are described and the results are reported. Comparison with experimental results will be made as far as possible. The main take-home message is that sediment can be dispersed to a distance of about 20 kms from the disturbance source, and overall may persist about four days – the rest of the sediment, of less than 20 μm in size, may be convected with the current over a longer distance and over a longer period, but is associated with an insignificant concentration level of less than 1 g/m3.