Lattice Boltzmann Methods for Fluid Structure Interaction

• Main Author: Blair, Stuart R.
• Other Authors: Kwon, Young W.
• Published: Monterey, California. Naval Postgraduate School 2012
• Online Access: http://hdl.handle.net/10945/17325

Approved for public release; distribution is unlimited === The use of lattice Boltzmann methods (LBM) for fluid flow and its coupling with finite element method (FEM) structural models for fluid-structure interaction (FSI) is investigated. A body of high performance LBM software that exploits graphic processing unit (GPU) and multiprocessor programming models is developed and validated against a set of two- and three-dimensional benchmark problems. Computational performance is shown to exceed recently reported results for single-workstation implementations over a range of problem sizes. A mixed-precision LBM collision algorithm is presented that retains the accuracy of double-precision calculations with less computational cost than a full double-precision implementation. FSI modelling methodology and example applications are presented along with a novel heterogeneous parallel implementation that exploits task-level parallelism and workload sharing between the central processing unit (CPU) and GPU that allows significant speedup over other methods. Multi-component LBM fluid models are explicated and simple immiscible multi-component fluid flows in two-dimensions are presented. These multi-component fluid LBM models are also paired with structural dynamics solvers for two-dimensional FSI simulations. To enhance modeling capability for domains with complex surfaces, a novel coupling method is introduced that allows use of both classical LBM (CLBM) and a finite element LBM (FELBM) to be combined into a hybrid LBM that exploits the flexibility of FELBM while retaining the efficiency of CLBM.