Beatriz Eguzkitza

A Parallel CFD Model for Wind Farms

We present a Computational Fluid Dynamics (CFD) modeling strategy for onshore wind farms aimed at predicting and opti- mizing the production of farms using a CFD model that includes meteorological data assimilation, complex terrain and wind turbine effects. The model involves the solution of the Reynolds-Averaged Navier-Stokes (RANS) equations together with a k-ɛ turbulence model specially designed for the Atmospheric Boundary Layer (ABL). The model involves automatic meshing and generation of boundary conditions with atmospheric boundary layer shape for the entering wind flow. As the integration of the model up to the ground surface is still not viable for complex terrains, a specific law of the wall including roughness effects is implemented. The wake effects and the aerodynamic behavior of the wind turbines are described using the actuator disk model, upon which a volumetric force is included in the momentum equations. The placement of the wind turbines and a mesh refinement for the near wakes is done by means of a Chimera method. The model is implemented in Alya, a High Performance Computing (HPC) multi physics parallel solver based on finite elements and developed at Barcelona Supercomputing Center.

Computational Fluid and Particle Dynamics Simulations for Respiratory System: Runtime Optimization on an Arm Cluster

Computational fluid and particle dynamics simulations (CFPD) are of paramount importance for studying and improving drug effectiveness. Computational requirements of CFPD codes involves high-performance computing (HPC) resources. For these reasons we introduce and evaluate in this paper system software techniques for improving performance and tolerate load imbalance on a state-of-the-art production CFPD code. We demonstrate benefits of these techniques on both Intel- and Arm-based HPC clusters showing the importance of using mechanisms applied at runtime to improve the performance independently of the underlying architecture. We run a real CFPD simulation of particle tracking on the human respiratory system, showing performance improvements of up to 2X, keeping the computational resources constant.

An Implicit and Parallel Chimera Type Domain Decomposition Method

The Chimera Method developed originally in [1, 19, 20] simplifies the construction of computational meshes about complex geometries. This is achieved by breaking the geometries into components and generating independently a series of different meshes. This enables one a great flexibility on the choice of the type of elements, their orientations and local mesh refinement. The components are further coupled by transmitting information from one mesh to the other to obtain a global solution.