Scientific Objectives

• To perform detailed wind tunnel experiments, large eddy simulations (LES) and direct numerical simulations (DNS) of dispersion from continuous and short-duration releases in simulated urban arrays for different geometries and wind directions under neutral stability. This will generate a comprehensive high-quality dataset of simultaneous flow and concentration data. The data thus generated will then be analysed to enable fulfilment of the other objectives.
• To quantify and parametrize the main exchange processes at intersections and in streets of finite extent, including the effects of secondary sources, three-dimensional flow structure, tall buildings and wind direction.
• To implement the new parametrizations into the SIRANE model, to apply the model to simulate realistic case studies in central London and to evaluate the model runs against data from the wind tunnel and LES. Model performance as a result of the improvements will be quantified against previous benchmark evaluations of the original model.