This paper presents a detailed study of the fluid dynamics inside a wall-flow filter and proposes a new pressure drop model. A 3D channel scale computational model of a filter validated with experiments is used. A detailed description of the pressure drop for flow entering, passing through and leaving the filter is provided. The computational grid is extensively analyzed, and it is found that wall-flow is very insensitive to the grid quality, opposite to the local pressure, which is very sensitive. Several flow rates and wall permeability are analyzed. The most critical assumptions commonly found in current models are discussed based on the results. It is found that the friction factor of the channels is non-constant, it is different for the inlet and the outlet channels, and both differ from that for pipes with non-porous walls. A new criterion to determine the flow inside the filter as fully developed is also presented. The wall-flow along the perimeter of a cross-section is observed to be variable, consistently for many flow rates and wall permeability. The results are also used to develop a comprehensive, physically based, pressure drop model that shows very good agreement with experimental data. It is found that the propagation error when using the model to back-calculate physical parameters is strongly sensitive to the experimental conditions; hence, guidelines to minimize it in further experiments are provided.

本文对壁流式过滤器内部的流体动力学进行了详细研究，并提出了一种新的压降模型。使用经过实验验证的滤波器的3D通道比例计算模型。提供了用于进入，通过和离开过滤器的流量的压降的详细说明。对计算网格进行了广泛的分析，发现壁流对网格质量非常不敏感，而与局部压力相反，它非常敏感。分析了几种流速和壁渗透率。基于结果讨论了当前模型中常见的最关键的假设。已经发现，通道的摩擦系数是非恒定的，其入口和出口通道的摩擦系数是不同的，并且两者都与具有无孔壁的管道的摩擦系数不同。还提出了确定过滤器内部流量的新标准，该标准已得到全面开发。观察到沿横截面周长的壁流是可变的，这对于许多流速和壁渗透率是一致的。结果还用于开发基于物理的综合压降模型，该模型与实验数据非常吻合。发现使用模型反算物理参数时的传播误差对实验条件非常敏感。因此，提供了在以后的实验中将其最小化的指南。结果还用于开发基于物理的综合压降模型，该模型与实验数据非常吻合。发现使用模型反算物理参数时的传播误差对实验条件非常敏感。因此，提供了在以后的实验中将其最小化的指南。结果还用于开发基于物理的综合压降模型，该模型与实验数据非常吻合。发现使用模型反算物理参数时的传播误差对实验条件非常敏感。因此，提供了在以后的实验中将其最小化的指南。