The paper presents a numerical analysis to investigate the temporal effect of shoulder cleaning on ballast drainage performance at various fouling conditions. Two parameters, the fouling index (FI) and the fouling profile (FP) are proposed to quantitatively represent the fouling conditions. A computational fluid dynamics (CFD) model including the Darcy-Forchheimer’s law to take into account the effect of porous medium is developed. Prior experimental results are used to extract model configuration parameters for improved simulation accuracy. Parametric simulations are carried out to evaluate flow characteristics through the ballast layer before and after shoulder cleaning for different FIs and FPs. Service life-dependent mathematical models of FI and FP are also introduced to capture the temporal effect of shoulder cleaning on drainage performance. Our analysis indicates that the optimal maintenance schedule needs to be decided with a balanced consideration of both the drainage health and the potential of drain restoration during the service life.

本文提供了一个数值分析，以研究在各种污垢条件下肩部清洁对压载物排水性能的时间影响。提出了两个参数，结垢指数（FI）和结垢曲线（FP）来定量表示结垢条件。建立了包括达西-福希海默定律在内的考虑多孔介质影响的计算流体动力学（CFD）模型。先前的实验结果用于提取模型配置参数，以提高仿真精度。进行参数模拟以评估不同FI和FP肩部清洁前后通过压载层的流动特性。还引入了与使用寿命相关的FI和FP数学模型，以捕获肩部清洁对排水性能的时间影响。