This project brings together communities from the UK Turbulence Consortium (UKTC) and the UK Consortium on Reacting Flows (UKCRF) to ensure a smooth transition to exascale computing, with the aim to develop transformative techniques for future-proofing their production simulation software ecosystems dedicated to the study of turbulent flows.
Understanding, predicting and controlling turbulent flows is of central importance and a limiting factor to a vast range of industries. Many of the environmental and energy-related issues we face today cannot possibly be tackled without a better understanding of turbulence.
This project is aiming at re-engineering and extending the capabilities of four production and research flow solvers for exascale computing: XCOMPACT3D, OpenSBLI, UDALES and SENGA+. These open-source, well-established, community flow solvers are based on finite-difference methods on structured meshes and will be developed to meet the challenges associated with exascale computing while taking advantage of the significant opportunities afforded by exascale systems. A key aim of this project is to leverage the well-established Domain Specific Language (DLS) framework OPS and the 2DECOMP&FFT library to allow XCOMPACT3D, OPENSBLI, UDALES and SENGA+ to run on large-scale heterogeneous computers. OPS was developed in the UK in the last ten years and it targets applications on multi-block structured meshes. It can currently generate code using OPENCUDA, OPENACC/OPENMP5.0, OPENCL, SYCL/ONEAPI, HIP and their combinations with MPI.
The OPS DSLs’ capabilities will be extended in this project, specifically its code-generation tool-chain for robust, fail-safe parallel code generation. A related strand of work will use the 2DECOMP&FFT a Fortran-based library based on a 2D domain decomposition for spatially implicit numerical algorithms on monobloc structured meshes. The library includes a highly scalable and efficient interface to perform Fast Fourier Transforms (FFTs) and relies on MPI providing a user-friendly programming interface that hides communication details from application developers. 2DECOMP&FFT will be completely redesigned for a use on heterogeneous supercomputers (CPUs and GPUS from different vendors) using a hybrid strategy.
The project combines exascale-ready coupling interfaces, UQ capabilities, I/O & visualisation tools to our flow solvers, as well as machine learning based algorithms. This is done in collaboration with several of the recently funded ExCALIBUR cross-cutting projects. The project focuses on four high-priority use cases (one for each solver), defined as high quality, high impact research made possible by a step-change in simulation performance. The use cases are targeting wind energy, green aviation, air quality and net-zero combustion. Exascale computing will be a game changer in these areas and will contribute to make the UK a greener nation (The UK commits to net zero carbon emissions by 2050). The use cases will be used to demonstrate the potential of the re-designed flow solvers based on OPS and 2DECOMP&FFT, for a wide range of hardware and parallel paradigms.
- A high-fidelity simulation of a full-scale offshore wind farm during operation, within the Xcompact3d framework,
- A high-fidelity simulation of a NACA0012 airfoil with shock-capturing at high-speed, within the OpenSBLI framework.
- A high-fidelity simulation of the flow over London using realistic geometry with realistic atmospheric information, within the uDALES code
- A high-fidelity simulation of turbulent premixed swirl flames involving High Hydrogen Content (HHC) fuels and premixed flame-wall interaction in turbulent boundary layers for rich hydrogen-air mixtures, within the SENGA code
Outreach activities
Podcast “Turbulence at the exascale”
