OpenSBLI: Automated code-generation for heterogeneous computing architectures applied to compressible fluid dynamics on structured grids

Abstract

OpenSBLI is an open-source code-generation system for compressible fluid dynamics (CFD) on heterogeneous computing architectures. Written in Python, OpenSBLI is an explicit high-order finite-difference solver on structured curvilinear meshes. Shock-capturing is performed by a choice of high-order Weighted Essentially Non-Oscillatory (WENO) or Targeted Essentially Non-Oscillatory (TENO) schemes. OpenSBLI generates a complete CFD solver in the Oxford Parallel Structured (OPS) domain specific language. The OPS library is embedded in C code, enabling massively-parallel execution of the code on a variety of high-performance-computing architectures, including GPUs. The present paper presents a code base that has been completely rewritten from the earlier proof of concept Jacobs et al. (2017) [7], allowing shock capturing, coordinate transformations for complex geometries, and a wide range of boundary conditions, including solid walls with and without heat transfer. A suite of validation and verification cases are presented, plus demonstration of a large-scale Direct Numerical Simulation (DNS) of a transitional Shockwave Boundary Layer Interaction (SBLI). The code is shown to have good weak and strong scaling on multi-GPU clusters. We demonstrate that code-generation and domain specific languages are suitable for performing efficient large-scale simulations of complex fluid flows on emerging computing architectures. Program summaryProgram Title: OpenSBLI code-generation framework for compressible fluid dynamics on heterogeneous architecturesCPC Library link to program files:https://doi.org/10.17632/3sdb6hck2c.1Developer's repository link:https://github.com/opensbli/opensbliLicensing provisions: GPLv3Programming languages: Python, C/C++, OPS DSLNature of problem: The compressible 3D Navier-Stokes equations are solved via Implicit Large Eddy Simulation (ILES) or Direct Numerical Simulation (DNS).Solution method: OpenSBLI [1,2] is a Python-based code-generation system that uses symbolic algebra to generate a complete CFD solver in C/C++. The basic algorithm is a stencil-based finite-difference solver on structured curvilinear meshes. Shock-capturing is performed by a selection of high-order Weighted/Targeted Essentially Non-Oscillatory (WENO/TENO) schemes. Explicit low-storage Runge-Kutta schemes are used for time-advancement.Additional comments including restrictions and unusual features: The generated code is compliant with the Oxford Parallel Structured (OPS) [3] software library. OpenSBLI/OPS executables can be generated for the OpenMP, MPI, CUDA, OpenCL, and OpenACC parallel programming paradigms. Multi-GPU support is available via combinations of MPI with CUDA, OpenCL or OpenACC.