Full-scale measurements of natural ventilation of a large semi-enclosed stadium: Suitability for CFD validation

Computational Fluid Dynamics (CFD) studies of natural ventilation of buildings in urban areas should be validated concerning both the wind-flow pattern around the buildings and the indoor airflow driven by wind and buoyancy. Reduced-scale wind tunnel measurements can suffer from similarity requirements. In particular cases, when urban wind flow and buoyancy effects are combined, it is even impossible to fulfil these requirements. Given the large difficulties in obtaining reliable reduced-scale data, this paper presents a unique set of fullscale on-site measurement data of natural ventilation in the large semi-enclosed Amsterdam ArenA stadium in the Netherlands. The measurements were performed to provide experimental data for CFD validation. Although the repeatability of full-scale on-site measurements is in general quite low, nearly identical meteorological and indoor environmental conditions were present on the three consecutive concert evenings. Furthermore, the calculated air exchange rate based on CO₂ concentration decay measurements showed that also the natural ventilation on the three evenings was almost equal.