ABSTRACT Good air quality is one of the main requirements of human health. Jet fan ventilators are often applied for pollutant removal in large enclosures, where lack of fresh air is significant. During the design phase, computational fluid dynamic (CFD) techniques are most often used to verify the effectiveness of ventilation. However, reliable designs based on CFD, require accurate jet fan airstream modelling. The paper intends to present the best turbulence model (as available in FDS) for modelling of a jet fan in FDS. For that measurements of longitudinal velocity distribution of air supplied from the jet fan are performed and presented. Results from CFD simulations for the same geometry in which measurements are performed are compared with that. The outcome proposes use of specific turbulence models as available in FDS for this configuration. It is proven that the default Deardorff model for the FDS 6 is not the most accurate for jet fan stream simulations. Moreover, the results show that sloped jet fan airstreams are modelled correctly only with fine meshes, and this can have a significant impact on increasing computational costs.

中文翻译：

---

火动力学模拟器代码中射流风机通风系统建模的实际问题

摘要 良好的空气质量是人类健康的主要要求之一。喷射风扇通风机通常用于在缺乏新鲜空气的大型封闭空间中去除污染物。在设计阶段，计算流体动力学 (CFD) 技术最常用于验证通风的有效性。然而，基于 CFD 的可靠设计需要精确的射流风扇气流建模。本文旨在展示用于 FDS 中喷气风扇建模的最佳湍流模型（在 FDS 中可用）。为此，执行并介绍了从射流风扇供应的空气的纵向速度分布的测量。将执行测量的相同几何体的 CFD 模拟结果与其进行比较。结果建议使用 FDS 中可用的特定湍流模型用于此配置。事实证明，FDS 6 的默认 Deardorff 模型对于射流风扇流模拟并不是最准确的。此外，结果表明倾斜射流风扇气流仅使用精细网格才能正确建模，这会对增加计算成本产生重大影响。