While new power-efficient computer architectures exhibit spectacular theoretical peak performance, they require specific conditions to operate efficiently, which makes porting complex algorithms a challenge. Here, we report results of the semi-implicit method for pressure linked equations (SIMPLE) and the pressure implicit with operator splitting (PISO) methods implemented on the graphics processing unit (GPU). We examine the advantages and disadvantages of the full porting over a partial acceleration of these algorithms run on unstructured meshes. We found that the full-port strategy requires adjusting the internal data structures to the new hardware and proposed a convenient format for storing internal data structures on GPUs. Our implementation is validated on standard steady and unsteady problems and its computational efficiency is checked by comparing its results and run times with those of some standard software (OpenFOAM) run on central processing unit (CPU). The results show that a server-class GPU outperforms a server-class dual-socket multi-core CPU system running essentially the same algorithm by up to a factor of 4.
See also supplementary materials and the follow up at http://vratis.com/blog/?p=7.
(Tadeusz Tomczak, Katarzyna Zadarnowska, Zbigniew Koza, Maciej Matyka and Łukasz Mirosław: “Acceleration of iterative Navier-Stokes solvers on graphics processing units”, International Journal of Computational Fluid Dynamics, accepted, July 2013. [DOI])
The OpenFOAM CFD Toolbox is a free, open source CFD software package produced by OpenCFD Ltd. Its user base represents a wide range of engineering and science disciplines in both commercial and academic organizations. OpenFOAM has an extensive range of features to solve a wide range of fluid flows and physics phenomenon. OpenFOAM provides tools for all three stages of CFD, preprocessing, solvers, and post processing. Almost all are capable of being run in parallel as standard making it an important resource for a wide range of scientists and engineers using HPC for CFD.
General-purpose Graphics Processing Unit (GPU) technology is increasingly being used to accelerate compute-intensive HPC applications across various disciplines in the HPC community. OpenFOAM CFD simulations can take a significant amount of time and are computationally intensive. Comparing various alternatives for enabling faster research and discovery using CFD is of key importance. SpeedIT libraries from Vratis provide GPU-accelerated iterative solvers that replace the iterative solvers in OpenFOAM.
In order to investigate the GPU-acceleration of OpenFOAM, we simulate the three dimensional lid-driven cavity problem based on the tutorial provided with OpenFOAM. The 3D lid-driven cavity problem is an incompressible flow problem solved using OpenFOAM icoFoam solver. The majority of the computationally intensive portion of the solver is the pressure equation. In the case of acceleration, only the pressure calculation is offloaded to the GPUs. On the CPUs, the PCG solver with DIC preconditioner is used. In the GPU-accelerated case, the SpeedIT 2.1 algebraic multigrid precoditioner with smoothed aggregation (AMG) in combination with the SpeedIT Plugin to OpenFOAM is used.
ACUSim vortex shedding
From a recent press release:
ACUSIM Software, Inc., a leader in computational fluid dynamics (CFD) technology and solutions, today announced the immediate availability of AcuSolve™ 1.8, the latest version of ACUSIM’s leading general-purpose, finite-element based CFD solver. ACUSIM will demonstrate AcuSolve 1.8 during two free webinars, taking place at 9:30 a.m. – 10:30 a.m. ET and 6:30 p.m. – 7:30 p.m. ET, on Oct. 26, 2010, at http://www.acusim.com/html/events.html.
Used by designers and research engineers with all levels of expertise, AcuSolve is highly differentiated by its accelerated speed, robustness, accuracy and multiphysics/multidisciplinary capabilities. Contributing to its robustness is the product’s Galerkin/Least-Square (GLS) finite element formulation and novel iterative linear equation solver for the fully coupled equation system. The combination of these two powerful technologies provides a highly stable and efficient solver, capable of handling unstructured meshes with tight boundary layers automatically generated from complex industrial geometries. Read the rest of this entry »
ECCOMAS CFD 2010, one of the world’s most important conferences in the field of CFD, is proud to announce a mini-symposium on “GPU Computing in Computational Fluid Dynamics”, organised by Stefan Turek and Dominik Göddeke.
Contributions to this event are cordially invited and should include a tentative title and an extended abstract. Submissions are due no later than December 15 (via email to stefan.turek (at) math.tu-dortmund.de). For details, please contact Stefan Turek or Dominik Göddeke.
Support of this mini-symposium by German BMBF (SKALB project) is gratefully acknowledged.