TY - JOUR
T1 - NURBS-SEM: A hybrid spectral element method on NURBS maps for the solution of elliptic PDEs on surfaces
JF - COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
Y1 - 2018
A1 - Giuseppe Pitton
A1 - Luca Heltai
VL - 338
UR - https://arxiv.org/abs/1804.08271
ER -
TY - JOUR
T1 - A natural framework for isogeometric fluid-structure interaction based on BEM-shell coupling
JF - COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
Y1 - 2017
A1 - Luca Heltai
A1 - Kiendl, J.
A1 - Antonio DeSimone
A1 - Alessandro Reali
VL - 316
UR - http://cdsads.u-strasbg.fr/abs/2017CMAME.316..522H
ER -
TY - JOUR
T1 - Nonsingular Isogeometric Boundary Element Method for Stokes Flows in 3D
Y1 - 2014
A1 - Luca Heltai
A1 - Marino Arroyo
A1 - Antonio DeSimone
KW - Isogeometric Analysis
AB - Isogeometric analysis (IGA) is emerging as a technology bridging Computer Aided Geometric Design (CAGD), most commonly based on Non-Uniform Rational B-Splines (NURBS) surfaces, and engineering analysis. In finite element and boundary element isogeometric methods (FE-IGA and IGA-BEM), the NURBS basis functions that de- scribe the geometry define also the approximation spaces. In the FE-IGA approach, the surfaces generated by the CAGD tools need to be extended to volumetric descriptions, a major open problem in 3D. This additional passage can be avoided in principle when the partial differential equations to be solved admit a formulation in terms of bound- ary integral equations, leading to Boundary Element Isogeometric Analysis (IGA-BEM). The main advantages of such an approach are given by the dimensionality reduction of the problem (from volumetric-based to surface-based), by the fact that the interface with CAGD tools is direct, and by the possibility to treat exterior problems, where the computational domain is infinite. By contrast, these methods produce system matrices which are full, and require the integration of singular kernels. In this paper we address the second point and propose a nonsingular formulation of IGA-BEM for 3D Stokes flows, whose convergence is carefully tested numerically. Standard Gaussian quadrature rules suffice to integrate the boundary integral equations, and carefully chosen known exact solutions of the interior Stokes problem are used to correct the resulting matrices, extending the work by Klaseboer et al. [27] to IGA-BEM.
PB - Elsevier
UR - http://hdl.handle.net/1963/6326
U1 - 6250
U2 - Mathematics
U4 - 1
U5 - MAT/08 ANALISI NUMERICA
ER -
TY - JOUR
T1 - Numerical Strategies for Stroke Optimization of Axisymmetric Microswimmers
JF - Mathematical Models and Methods in Applied Sciences 21 (2011) 361-387
Y1 - 2011
A1 - François Alouges
A1 - Antonio DeSimone
A1 - Luca Heltai
KW - Optimal swimming
AB - We propose a computational method to solve optimal swimming problems, based on the boundary integral formulation of the hydrodynamic interaction between swimmer and surrounding fluid and direct constrained minimization of the energy consumed by the swimmer. We apply our method to axisymmetric model examples. We consider a classical model swimmer (the three-sphere swimmer of Golestanian et al.) as well as a novel axisymmetric swimmer inspired by the observation of biological micro-organisms.
PB - World Scientific
UR - http://hdl.handle.net/1963/3657
U1 - 648
U2 - Mathematics
U3 - Functional Analysis and Applications
ER -