The developed Data Exchange & Workflow Portal will be able to simplify or even eliminate these obstacles. First activities have already started. The new platform enables users to easily access the two HLRS clusters, Hawk and Vulcan, from any authorised device and to run their simulations remotely. The portal provides relevant HPC processes for the end users, such as uploading input decks, scheduling workflows, or running HPC jobs.

In order to be able to perform data analytics, i.e. modal decomposition, of the large amounts of data that arise from Exascale simulations, a modal decomposition toolkit has been developed. An efficient and scalable parallelisation concept based on MPI and LAPACK/ScaLAPACK has been used to perform modal decompositions in parallel on large data volumes. Since DMD and POD are data-driven decomposition techniques, the time resolved data has to be read for the whole time interval to be analysed. To handle the large amount of input and output, the software tool has been optimised to effectively read and write the time resolved snapshot data parallelly in time and space. Since different solution data formats are utilised by the computational fluid dynamics community, a flexible modular interface has been developed to easily add data formats of other simulation codes.

The flow field of the investigated combustor exhibits a self-excited flow oscillation known as a precessing vortex core (PVC) at a dimensionless Strouhal Number of Sr=0.55, which can lead to inefficient fuel consumption, high level of noise and eventually combustion hardware damage. To analyse the dynamics of the PVC, DMD is used to extract the large-scale coherent motion from the turbulent flow field characterised by a manifold of different spatial and temporal scales shown in Figure 2 (left). The instantaneous flow field of the turbulent flame is visualised by an iso-surface of the Q-criterion coloured by the absolute velocity. The DMD analysis is performed on the three-dimensional velocity and pressure field using 2000 snapshots. The resulting spectrum of the DMD, showing the amplitude of each mode as a function of the dimensionless frequency is given in Figure 2 (top). One dominant mode, marked by a red dot, at Sr=0.55 matching the dimensionless frequency of the PVC is clearly visible. The temporal reconstruction of the extracted DMD mode showing the extracted PVC vortex is illustrated in Figure 2 (right). It shows the iso-surface of the Q-criterion coloured by the radial velocity.