GAMES Webinar 2023 – 299期(复杂流体现象物理仿真) | 李伟(Tencent Shanghai, LightSpeed Studios)，尹航(UC San Diego)
【GAMES Webinar 2023-299期】(模拟与动画专题-复杂流体现象物理仿真)
报告嘉宾：李伟(Tencent Shanghai, LightSpeed Studios)
报告题目：Fluid-Solid Coupling in Kinetic Two-Phase Flow Simulation
Real-life flows exhibit complex and visually appealing behaviors such as bubbling, splashing, glugging and wetting that simulation techniques in graphics have attempted to capture for years. While early approaches were not capable of reproducing multiphase flow phenomena due to their excessive numerical viscosity and low accuracy, kinetic solvers based on the lattice Boltzmann method have recently demonstrated the ability to simulate water-air interaction at high Reynolds numbers in a massively-parallel fashion. However, robust and accurate handling of fluid-solid coupling has remained elusive: be it for CG or CFD solvers, as soon as the motion of immersed objects is too fast or too sudden, pressures near boundaries and interfacial forces exhibit spurious oscillations leading to blowups. Built upon a phase-field and velocity-distribution based lattice-Boltzmann solver for multiphase flows, this paper spells out a series of numerical improvements in momentum exchange, interfacial forces, and two-way coupling to drastically reduce these typical artifacts, thus significantly expanding the types of fluid-solid coupling that we can efficiently simulate. We highlight the numerical benefits of our solver through various challenging simulation results, including comparisons to previous work and real footage.
Wei Li is really interested in physical simulation. Currently, He is a senior research scientist at Tencent Shanghai, LightSpeed Studios and he also hires research interns at Tencent Games all year round. Previously, He was a Postdoc at Inria Saclay, supervised by Prof. Mathieu Desbrun. He obtained his doctorate from the School of Information Science & Technology of ShanghaiTech University in China, supervised by Prof. Xiaopei Liu, and majoring in computer graphics, with a particular focus on fluid simulations. Differing from traditional fluid simulation, his research is multi-disciplinary, covering many aspects of computer science and computational physics, as well as using artificial intelligence in physical simulations. During his PhD study, he closely collaborated with Prof. Mathieu Desbrun from Caltech and Prof. Changxi Zheng from Columbia University for fluid simulation. He received his BS degree in computer science from Northwestern Polytechnical University, China, supervised by Prof. Yong Xia.
报告嘉宾：尹航 Hang “Hesper” Yin(UC San Diego)
The vorticity-streamfunction formulation for incompressible inviscid fluids is the basis for many fluid simulation methods in computer graphics, including vortex methods, streamfunction solvers, spectral methods, and Monte Carlo methods. We point out that current setups in the vorticity-streamfunction formulation are insufficient at simulating fluids on general non-simply-connected domains. This issue is critical in practice, as obstacles, periodic boundaries, and nonzero genus can all make the fluid domain multiply connected. These scenarios introduce nontrivial cohomology components to the flow in the form of harmonic fields. The dynamics of these harmonic fields have been previously overlooked. In this paper, we derive the missing equations of motion for the fluid cohomology components. We elucidate the physical laws associated with the new equations, and show their importance in reproducing physically correct behaviors of fluid flows on domains with general topology.
Hang “Hesper” Yin is a second-year PhD student at UC San Diego Center for Visual Computing advised by professor Albert Chern. Her research interests lie in computer graphics, and especially geometry processing and physical simulations. She received her bachelor’s degree at Carnegie Mellon University School of Computer Science, where she was a part of Prof. Keenan Crane’s Geometry Collective and Prof. David Lindlbauer’s Augmented Perception Lab. Besides her study, she also spent wonderful time interning at EPFL Geometric Computing Lab, Taichi Graphics, and Adobe Research, where she gained experiences on different kinds of simualtions and geometry processing.
王笑琨，北京科技大学智能科学与技术学院副教授，英国国家计算机动画中心Marie-Curie Fellow，入选欧盟玛丽居里学者、北科青年学者、北京科协青年人才托举工程。CCF计算机辅助设计与图形学专委会、人机交互专委会，CAAI智慧医疗专委会，CSIG人机交互专委会等委员。主要研究方向包括图形与虚拟现实，智能交互与仿真等，在SIGGRAPH Asia，IEEE VR、EG、SCA、CGI、CGF等主流期刊会议上发表论文30余篇。曾获CGI2020最佳论文，CCF CAD & CG2022最佳学生论文，CASA 2022 AniNex最佳论文，中国黄金协会科技进步一等奖，中国电子学会科技进步二等奖，全国优秀城乡规划设计三等奖等。主持承担了国家自然科学基金、国家重点研发计划子课题、国家高端外国专家项目等10余项课题。
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