Opaque ventilated façades have gained attention in the last years due to their cooling load reduction. The double skin façade (DSF) is a well-known device and is an ideal system to combine with evaporative cooling solutions, like water spray systems. The aim of the present study is to determine the façade air cavity width and spray water characteristics (the spray water droplet size, and the number of spray nozzles) through a numerical simulation. The temperature at the centre of the cavity and the cooling efficiency are employed as the design variables to improve the thermal performance of an opaque double skin facade. The CFD simulations showed good agreement with experimental measurements. The performed numerical method is a valuable tool to design and evaluate double skin façades, considering buoyancy effects and water particles evaporation simultaneously. According to the results, the best arrangement of the DSF for hot-arid condition with an evaporative cooling strategy is an air cavity of 0.4 m, a droplet size of 25 μm and a separation of 0.6 m between each nozzle.

不透明通风立面由于降低了冷却负荷而在最近几年受到关注。双层外墙（DSF）是一种众所周知的设备，是与蒸发冷却解决方案相结合的理想系统，例如喷水系统。本研究的目的是通过数值模拟确定立面气腔宽度和喷水特性（喷水水滴大小和喷嘴数量）。空腔中心的温度和冷却效率被用作设计变量，以改善不透明双层蒙皮外墙的热性能。CFD仿真显示与实验测量结果吻合良好。执行的数值方法是设计和评估双层外观的宝贵工具，同时考虑浮力效应和水颗粒蒸发。根据结果​​，采用蒸发冷却策略的热干燥条件下，DSF的最佳布置是空气腔为0.4 m，液滴尺寸为25μm，每个喷嘴之间的间距为0.6 m。