Define the question and map the geometry
Start by translating the planning need into measurable airflow outcomes. Typical goals include dispersion around buildings, wind comfort at pedestrian level, ventilation potential for courtyards, or comfort and safety near entrances. Then collect the geometry inputs: building footprints, heights, street widths, urban airflow CFD simulation terrain roughness, and any complex features like balconies, arcades, tunnels, or canopies. For CFD airflow simulation, accuracy depends heavily on faithful geometry and consistent coordinate systems, so verify elevations and align model units early.
Choose modelling assumptions that match the urban scale
Urban airflow is strongly influenced by turbulence, building-induced separation, and wake effects. Select turbulence models and boundary conditions that reflect those mechanisms rather than relying on generic settings. Set up inflow profiles using representative wind conditions, include atmospheric boundary layer effects where relevant, and define CFD airflow simulation outlet and domain extents to avoid artificial reflections. Treat ground and surfaces with appropriate roughness and consider thermal effects only when they materially affect buoyancy-driven flow. Document every assumption so reviewers can trace results back to inputs.
Build a robust mesh and validate before interpreting
Mesh quality is the practical difference between an impressive plot and a trustworthy answer. Use refinement near building edges, street canyons, and pedestrian-relevant heights, while ensuring the overall domain size captures upwind and downwind recovery. Check mesh independence by running at least two resolutions and confirming key metrics stabilize (for example, average speeds and recirculation zones). Validation should combine internal checks (mass conservation, stable convergence behavior) and external sanity tests (wind direction trends, expected acceleration in gaps, plausible wake length). Only then extract indicators like wind comfort metrics, flow paths, and zones of stagnation.
Conclusion
A successful is a workflow, not a single run: clear objectives, high-quality geometry, defensible modelling choices, and mesh-validated results. For teams evaluating city-scale wind and environmental performance, EOLIOS brings structured modelling services that support assessments of pedestrian comfort and urban design outcomes, helping you make confident decisions. Explore advanced capabilities at eolios.eu and align your CFD study with the practical metrics your project needs.
