Abstract. The dispersion of cooking-generated aerosols from an urban street canyon is examined with building-resolving computational fluid dynamics (CFD). Using a comprehensive urban CFD model (PALM) with a sectional aerosol module (SALSA), emissions from deep frying and boiling are considered for near-ground and elevated sources. It is found that, with representative choices of the source flux, the inclusion of aerosol dynamic processes decreases the mean canyon-averaged number concentration by 15–40 % for cooking emissions, whereas the effect is significantly weaker for traffic-generated aerosols. The effects of deposition and coagulation are comparable for boiling, but coagulation dominates for deep frying. Deposition is maximised inside the leeward corner vortices, while coagulation increases away from the source. The characteristic timescales are invoked to explain the spatial structure of deposition and coagulation. In particular, the relative difference between number concentrations for simulations with and without coagulation are strongly correlated with the ageing of particles along fluid trajectories or the mean tracer age.

中文翻译：

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技术说明：城市街道峡谷中烹饪产生的气溶胶的分散

摘要。使用建筑物解析计算流体动力学 (CFD) 检查来自城市街道峡谷的烹饪产生的气溶胶的分散情况。使用带有分段气溶胶模块 (SALSA) 的综合城市 CFD 模型 (PALM)，考虑了近地源和高架源的油炸和沸腾排放。研究发现，通过选择具有代表性的源通量，气溶胶动态过程的包含将烹饪排放的平均峡谷平均数量浓度降低了 15-40%，而对交通产生的气溶胶的影响要弱得多。沉积和凝结的影响与煮沸相当，但凝结在油炸中占主导地位。背风角涡流内的沉积最大化，而远离源的凝结增加。调用特征时间尺度来解释沉积和凝结的空间结构。特别是，有和没有凝结的模拟的数量浓度之间的相对差异与粒子沿流体轨迹的老化或平均示踪剂年龄密切相关。