Talk on "Direct Numerical Simulation of Decaying Homogeneous Isotropic Turbulence with Lattice Boltzmann Methods"
Speaker: Mr. Stephan Simonis (Ph.D. research scholar, Karlsruhe Institute of Technology, Germany).
Title: Direct Numerical Simulation of Decaying Homogeneous Isotropic Turbulence with Lattice Boltzmann Methods
Abstarct: Despite the multiple uses of lattice Boltzmann methods (LBM) as an alternative approach to computational fluid dynamics (CFD), especially turbulent flow simulations with LBM require further validation and important developments of established Navier-Stokes solvers have to be caught up. Regardless of the academic character of benchmark tests on highly simplified homogeneous isotropic turbulence (HIT), fundamental statements can be made about the numerical method itself and the development of turbulence models. In the presented work, stability, consistency, and accuracy of commonly used lattice Boltzmann schemes are investigated by means of numerical experiments on direct numerical simulation (DNS) of decaying homogeneous isotropic turbulence (DHIT). As a paragon for Kolmogorov's theory on HIT, the Taylor-Green vortex is chosen as a benchmark problem and numerical solutions are evaluated in terms of global turbulence quantities. Intermediate Reynolds numbers and two-parameter scalings are used to investigate mesh-convergence of the LBM. The results give insight into essential differences of the distinct collision schemes and enable further recommendations on parameter choices.
Speaker Bio: Stephan Simonis is a Ph.D. student at the Institute for Applied and Numerical Mathematics at Karlsruhe Institute of Technology (KIT), Germany. He obtained his master's and bachelor's degree at KIT, both in Mathematics, and spend a funded exchange year (ERS+) at the Royal Institute of Technology (KTH) in Stockholm, Sweden. Currently, his research focuses on discrete velocity models, relaxation systems and lattice Boltzmann methods for partial differential equations. As a part of the interdisciplinary Lattice Boltzmann Research Group headed by Dr. Mathias J. Krause, he contributes to their open-source framework OpenLB (www.openlb.net) which addresses a vast range of transport problems (e.g. in CFD) with LBM and allows for fast implementation in both, academic testing and advanced engineering applications.
Event Date: 01st August, 2019(Thursday)
Event Time: 02:30PM