An investigation into parameters affecting an optimum ventilation design of high density cities

For a high density city, given the need to accommodate a fix amount of building volume, what can one do to optimise the benefits of the natural (air) environment? It is hypothesised that in densely built cities, the amount of gaps, permeability and porosity of the cityscape will affect the ventilation / wind environment. Using wind tunnel, experiments are conducted with different amount and positions of gaps of a simplified city layout. The Air change potentials of buildings, an indicator of the air ventilation potential of the urban environment, as well as the air speed at pedestrian level are calculated. It can be established that a cityscape with more gaps will perform better. But it is noted that the characteristics instead of the amount of gaps are more important parameters. Based on the investigation, a number of guidelines have been established.