Abstract Proper postharvest temperature management is required to maintain the quality of fresh fruit such as pears. Understanding and evaluating the cooling process is crucial. In this context, numerical modelling techniques such as computational fluid dynamics (CFD) can provide complementary insights to experimental measurements. Fruit come in a variety of shapes that are also cultivar-dependent. In this work, CFD modelling was combined with X-ray computed tomography (CT) to explore the differences in cooling characteristics of different pear fruit cultivars in cardboard boxes, as determined by variable fruit shape. First, CT images of boxes randomly filled with pear fruit were obtained. Next, horizontal forced-air cooling experiments with three different pear cultivars (cv. ‘Doyenne’, cv. ‘Conference’ and cv. ‘Durondeau’) were conducted in a pre-cooling setup. After CT image reconstruction of the box and fruit CAD geometry, CFD simulations with the actual pear filling were developed and validated with experimentally-obtained cooling profiles. The experimental data agreed very well with simulation results of three cultivars. Shape differences led to internal porosity variation of the fruit filled box that determined local airflow patterns and cooling behaviour. The cooling time of individual pears in a box differed up to 4 h and large differences in cooling time between the boxes with different pear cultivars were observed. Individual fruit shapes clearly influence cooling behaviour. This work demonstrates that cooling results depend on the filling pattern, so that several fillings need to be accounted for to have a realistic statistical average, which can be achieved by a previously developed shape model combined with discrete element modelling and CFD.

中文翻译：

---

通过将 CT 成像与显式 CFD 建模相结合，揭示形状变异性和品种对包装水果冷却的影响

摘要 梨等新鲜水果的品质需要适当的采后温度管理。了解和评估冷却过程至关重要。在这种情况下，计算流体动力学 (CFD) 等数值建模技术可以为实验测量提供补充见解。水果有多种形状，也取决于品种。在这项工作中，CFD 建模与 X 射线计算机断层扫描 (CT) 相结合，以探索不同梨果实品种在纸板箱中冷却特性的差异，这是由不同的果实形状决定的。首先，获得随机填充梨果实的盒子的 CT 图像。接下来，对三个不同梨品种（cv. 'Doyenne'、cv. 'Conference' 和 cv. 'Conference' 进行水平强制空气冷却实验）。'Durondeau') 在预冷装置中进行。在对盒子和水果 CAD 几何结构进行 CT 图像重建后，开发了实际梨馅的 CFD 模拟，并使用实验获得的冷却曲线进行了验证。实验数据与三个品种的模拟结果非常吻合。形状差异导致水果填充盒的内部孔隙率变化，这决定了局部气流模式和冷却行为。一个盒子中单个梨的冷却时间差异高达 4 小时，并且观察到不同梨品种的盒子之间的冷却时间差异很大。单个水果形状明显影响冷却行为。这项工作表明，冷却结果取决于填充模式，因此需要考虑多个填充物以获得实际的统计平均值，