Title: Geometric Programming with Voronoi Diagrams - Efficiency, Robustness and Applications
Biography: Bruno Levy is a senior researcher with Inria Nancy-Grand Est, and a member of the LORIA lab. He defended his Ph.D. thesis in 1999 and did a post-doc in Stanford. He was hired in 2000 by Inria. He is currently the head of the ALICE research team, that he created in 2004. He received the Inria young researcher award in 2011.
His main research topic is numerical geometry, that is to say mathematical algorithms for acquiring, transforming and optimizing the representation of 3D shapes. He developed several algorithms for geometry processing and mesh generation, such as Least Squares Conformal Maps, used to generate (u,v) texture mapping coordinates in several softwares, Manifold Harmonics, a Fourier-like spectral mesh analysis algorithm, and more recently, Voronoi Parallel Linear Enumeration, an algorithm for re-meshing surfaces and volumes.
Abstract: In this talk, I will focus on Voronoi diagrams, present efficient algorithms to compute them and demonstrate some applications. For instance, some mesh generation algorithms require to compute the intersection between a Voronoi diagram and another mesh. To obtain a both efficient and robust implementation of this operation, one needs to carefully consider the geometrical, combinatorial and numerical aspects of the problem. For the geometrical/combinatorial part of the problem, I will show how a basic consideration on the Voronoi cells leads to a simple yet efficient algorithm. As far as the numerical part of the problem is concerned, for the possibly degenerate cases, I will explain how to "push" all the difficulties towards the geometric predicates, and how to implement these predicates with a combination of arithmetic filters, exact arithmetics and symbolic perturbation.
The resulting algorithm computes the intersection between a nD voronoi diagram and a volumetric or a surfacic mesh, and can be used in various settings, comprising surface re-meshing, anisotropic mesh generation and computation of optimal transport maps in 3d.
The presentation will be illustrated by live demos. Some source-code is available in the Graphite software. The automatic code generator for predicates PCK (Predicate Construction Kit) is available in the (upcoming) Geogram programming library.
Title: Coming soon
Biography: Coming soon
Abstract: Coming soon
Title: Advances in high order spectral/hp element methods for high Reynolds number complex geometry flows
Prof. Spencer Sherwin Biography: Spencer Sherwin is the McLaren Racing/Royal Academy of Engineering Research Chair in the Department of Aeronautics at Imperial College London. He received his MSE and PhD from the Department of Mechanical and Aerospace Engineering Department at Princeton University. During his time at Imperial he has maintained a successful research program into the development and application of the high order spectral/hp element techniques with particular application to biomedical flow, separated unsteady aerodynamics and understanding flow physics through instability analysis. Professor Sherwin’s research group (www.sherwinlab.info) also develops and distributes the openware spectral/hp element package nektar++ which has been applied to direct numerical simulation and stability analysis to a range of applications including Biomedical Flows and separated Bluff Bodies and Vortex Flows of relevance to offshore engineering and vehicle aerodynamics. He has published over 120 peer-reviewed papers in International Journals covering topics from numerical analysis to fundamental fluid-mechanics and biomedical flow modeling and co-authored a highly cited book on the underlying spectral/hp element methods. Currently he is an associate director EPSRC/EADS funded Laminar Flow Control Centre and is the chair of the EPSRC Platform for Research in Simulation Methods (PRISM) at Imperial College London (www.prism.ac.uk).
Dr. Joaquim Peiro Biography: Dr. Joaquim Peiro is a Senior Lecturer in the Department of Aeronautics. Since 1985 he has worked on research and development of CAD geometry modeling, automatic unstructured mesh generators and CFD solvers using linear and high-order elements. His research is focused on developing geometrical methods to interpret fluid flow features and behaviour, to determine how geometry influences fluid flow development, and the development of automatic procedures for modelling fluid-structure interaction. This includes automatic mesh generation for in vivo geometries reconstructed from medical images and high-order algorithms for compressible steady and transient flows in aeronautics and haemodynamics. He is one of the developers of the FELISA system for the numerical simulation of inviscid compressible flows using unstructured meshes funded by NASA. A current interest is the development and implementation of high-order techniques for mesh generation within the p-mesh framework in the open-ware spectral/hp element package Nektar++. He has more than 50 journal articles with citation data and they have been cited more than 1000 times. He is a member of the Editorial Board of International Journal of Numerical Methods in Biomedical Engineering.
Abstract: Coming soon
Title: CFD Meshing Challenges in Aerospace: It's About More Than Just Lift and Drag
Biography: Deryl Snyder is the Director of Aerospace and Defense at CD-adapco, globally the largest privately-owned CFD/CAE software and service provider. Deryl has over 15 years of computational fluid dynamics expertise related to the aerospace and defense industry. He received a Ph.D. jointly from Utah State University in the U.S. and the von Karman Institute for Fluid Dynamics in Belgium, specializing in numerical algorithms for CFD. He has worked as an engineering support contractor for the Munitions Directorate of the US Air Force Research Laboratory at Eglin Air Force Base solving aerodynamic technical issues for various missile systems and tactical UAVs. Deryl has also been a faculty member in the Mechanical Engineering Department at Brigham Young University, specializing in computational methods in the thermal/fluid sciences as well as small- and micro-UAV development. He led the CFD efforts in the Aerodynamics Center of Excellence at Lockheed Martin Missiles and Fire control from 2007 to 2011, where he was responsible for overseeing numerical analysis methods, procedures, practices, and tools. Since 2011, Deryl has overseen the aerospace and defense business at CD-adapco, working with customers, the product-delivery team, and developers to address simulation-related challenges in the industry.
Abstract: Coming soon
Title: Industrial Perspectives on Geometry Handling for Aerodynamics
Biography: Nigel graduated from the University of Southampton with a first-class honours degree in Aeronautics & Astronautics in 1987. Following a period of integrated experimental and computational research leading to the award of a PhD, he joined the Aerodynamics Department at DRA Farnborough in 1993. Here, his principal areas of work were in the design and assessment of high-lift/manoeuvre devices for combat aircraft and wind tunnel technique development. In 1999, he joined the Aerodynamics Group at MBDA Filton and became a Technical Expert for Missile Aerodynamics in 2004. He assumed his current role as Capability Leader, Aerodynamic Tools & Methods in 2006. Since 2003, Nigel has represented MBDA and the UK weapon aerodynamics community in various national fora, including the Aerodynamics National Advisory Committee, the Aerodynamics National Technical Committee and the Council of the UK Centre for Aerodynamics. He is also currently a member of the AIAA Meshing, Visualisation & Computational Environments Technical Committee.
Abstract: One of the most fundamental properties affecting the aerodynamic performance of a body is its shape. With progressively increasing demands for performance, the need to explore and optimise the performance of novel airframe shapes rapidly and with robust, efficient processes is becoming increasingly important. This poses significant challenges for the ways in which the associated geometry is generated and manipulated (in support of design) both on its wetted surfaces and in the adjacent air flow (i.e. the computational mesh). This presentation will review the processes associated with handling geometry to support industrial aerodynamic analyses – covering its receipt and preparation for use in analysis, though to its onward delivery - and will explain how they are influenced by the stage in the product lifecycle in which the analysis is being undertaken. Examples from the aircraft, turbo-machinery and missile sectors will be provided to illustrate key technology aspects. Insight will also be provided as to how current practice may develop in the future.