Abstract Current computational fluid dynamic (CFD) models of spray dryers lack the capability to predict the structure of the agglomerates formed; loose or compact agglomerates. This is mainly due to the conventional simplistic approach in numerically “fusing” of the colliding particles forming the agglomerate. A new theoretical treatment is introduced in this work, suitable for implementation in CFD simulations, which numerically fuses the particles and yet retain information on the structure of the agglomerate. This new theoretical treatment is based on tracking the reduction of the agglomerate surface area as the agglomerate is progressively formed. Analysis revealed that the reduction in the agglomerate surface area exhibits a unified correlation with the degree of compactness of the agglomerate. Further analysis comparing this new approach to the conventional numerical fusing of the particles revealed inherent numerical discrepancies, which has not been noted in the literature before. Understanding these discrepancies will provide clarity to the interpretation of the modelling and simulation of spray drying particle agglomeration in CFD. Moreover, this work lays the groundwork for a more comprehensive CFD model for agglomeration which can be potentially utilized to predict final powder properties.

中文翻译：

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在喷雾干燥机 CFD 建模中捕获颗粒团聚体的新视角

摘要 当前喷雾干燥器的计算流体动力学 (CFD) 模型缺乏预测形成的附聚物结构的能力；松散或致密的团聚体。这主要是由于形成团块的碰撞粒子在数值上“融合”的传统简单方法。在这项工作中引入了一种新的理论处理方法，适用于 CFD 模拟，它在数值上融合了粒子，但仍保留了关于团聚体结构的信息。这种新的理论处理基于随​​着团块逐渐形成而跟踪团块表面积的减少。分析表明，团块表面积的减少与团块的致密程度呈统一的相关性。将这种新方法与粒子的传统数值融合进行比较的进一步分析揭示了固有的数值差异，这在以前的文献中没有注意到。了解这些差异将为 CFD 中喷雾干燥颗粒团聚建模和模拟的解释提供清晰的解释。此外，这项工作为更全面的团聚 CFD 模型奠定了基础，该模型可用于预测最终的粉末特性。