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SpeedIT FLOW is a RANS single-phase fluid flow solver that runs fully on GPU. It supports OpenFOAM format and is about 3x faster than OpenFOAM running on 2xCPU.

SpeedIT FLOW is a RANS single-phase fluid flow solver that runs fully on GPU. It supports OpenFOAM format and is about 3x faster than OpenFOAM running on 2xCPU.

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- 1. SpeedIT FLOW: a GPU success story
- 2. A GPU Success Story in 5 steps* * Compare with Accelerated ANSYS Fluent presentation by Robert Strzodka (NVIDIA).
- 3. Step 1: Identify the application OpenFOAM Computational Fluid Dynamics Why OpenFOAM*: Free to use and open source, more and more popular in CFD community. Large user base across engineering industries, e.g. car, oil&gas, material, aviation, etc OPENFOAM® is a registered trademark of ESI Group. This offering is not approved or endorsed by ESI Group, the producer of the OpenFOAM software and owner of the OPENFOAM® and OpenCFD® trademarks.
- 4. Step 2: Identify the bottlenecks GPU ◼Partial acceleration (see Fig.) is not effective. ◼ofgpu (from Symscape), Culises (Fluidyna), NVIDIA (nvAMG) offer the mild acceleration for non-linear problems. ◼Maximal acceleration vs. Intel Xeon : ca. 1.8x (nvAMG). Problem: Amdahl’s Law should not be ignored. Solution: Implement the whole solver on GPU. Assemble Linear System of Equations Solve Linear System of Equations Converged ? ca. 40% of Runtime ca. 60% of Runtime Fig. Navier Stokes Equation calculation scheme.
- 5. Step 3: Parallelize the Algorithm ◼Implement non-linear solvers fully on GPU: ◼PISO and SIMPLE flow solvers* ◼AMG preconditioner (CUSP). ◼kOmegaSST turbulence model. ◼Various boundary conditions. * Acceleration of Iterative Navier-Stokes solvers on GPUs, Int J Comp Fluid Dynamics 07/2013; 27(4-5):201-209 GPU Assemble Linear System of Equations Solve Linear System of Equations Converged?
- 6. Step 4: Create Production-ready Library ◼Team of GPU specialists, physicists (Vratis, Wroclaw universities). ◼Understand the algorithm, parallelize with caution, adapt to GPU hardware limitations. ◼Invest in validation and testing with industrial partners. ◼Have fun working with industry leaders!
- 7. Step 5: Enjoy the acceleration Motorbike (OpenFOAM tutorial) 6.5M cells. external, aero, turbulent flow. simpleFoam, double precision Meshing on CPU Solving on GPU x.3.18 acceleration
- 8. Step 5: Enjoy the acceleration Aero* (based on Motorbike) 3M cells external, aero, turbulent flow. simpleFoam, double precision Meshing on CPU, solving on GPU x.2.76 acceleration * Geometry obtained from 4-id network.
- 9. Step 5: Enjoy the acceleration Solar Car* (based on Motorbike) 3.7M cells external, aero, turbulent flow. simpleFoam, double precision Meshing on CPU Solving on GPU x.2.85 acceleration * Geometry obtained from 4-id network.
- 10. SpeedIT FLOW: Hardware Hardware: CPU: 2 x Intel Xeon E5649 12M Cache, 2.53 GHz, 5.86 GT/s Intel® QPI, 96GB RAM 1333 MHz # cores: 2x6 # threads: 2x12 Software: OpenFOAM 2.1 GPU: Quadro K6000 12GB GDDR5 SDRAM OS: Ubuntu 12.04.4 LTS, 64 bit Software: SpeedIT FLOW
- 11. SpeedIT FLOW: OpenFOAM accelerator Use your GPU as an external accelerator for your OpenFOAM cases and use CPU as usual. 4 Aero Simulations on CPU: 4 x 5493 sec (12 CPU cores occupied) 4 Aero Simulations on GPU: 4 x 2100 sec. (1 CPU core occupied) … and your CPU is still not busy! You can use it for meshing, visualization, another simulations (Fig: 3xGPU + 1x11 CPU cores is 3.2x faster!).
- 12. What is SpeedIT FLOW ?
- 13. SpeedIT FLOW 1.0 ◼Integration: Dynamically linked library with public C-interface, Easy to use API. ◼Reader/Writer of OpenFOAM* cases. ◼GPU accelerated solvers: gico, gsimple, gpiso ◼Turbulence model: kOmegaSST. ◼Solves problem with geometries up to 7 million cells on a single card (with 12GB GPU RAM). ◼Supports AMD** and NVIDIA cards. * Tested with OpenFOAM ver. 2.0.1 ** SpeedIT FLOWCL to be released.
- 14. SpeedIT FLOW: usage ◼Run from command line simpleFoamToSpeedITflow -case ./myCaseInOF #OpenFOAM -> SpeedIT FLOW format conversion gpiso ./myCaseInOF & #solves the case on GPU. Use CPU for other tasks. paraFoam -case ./myCaseInOF # visualize the result. ◼Use API
- 15. Don’t wait. Just SpeedIT. Vratis Muchoborska 18 50-424 Wroclaw, Poland Questions? Contact us at: info@vratis.com

Full NameComment goes here.University of Zurichat University of Zurich The next goal is to replace diagonal preconditioner with Algebraic Multigrid preconditioner to further accelerate the whole solver on GPU.