The goal of this study was to optimize fibrous filter media by increasing the dust holding capacity (DHC) while maintaining the β ratio and initial pressure drop of the filter media. The key was the use of microstructure models to optimize the filter media. The microstructure of three different variations of a filter media for oil filtration was modeled by using the FiberGeo module of the GeoDict® software package. It was found that by optimizing the fiber volume distribution over the height of the filter media, higher DHC values could be achieved while keeping the pressure drop considerably low. This confirms the hypothesis that the macroscopic properties of the filter element can be improved by modifying the microstructure of the filter media.

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Hydroabrasion in particulate flows plays an important role in various industrial and natural processes. To predict the influence of it in a pipeline, channel or a fitting, it is essential to characterize the effects in a simple standardized geometry. An example to this is a pipe channel with a cylindrical obstacle adjusted inside the channel perpendicular to the flow direction. Results of flow field are generated by using the non-invasive Laser/Phase Doppler Anemometry (LDA/PDA) measurement technique. The velocity profiles of single phase and particulate flow from computational fluid dynamics (CFD) and discrete element method (DEM) simulations were validated by the LDA experimental data. The simulations were performed on the basis of Euler-Lagrange technique for both CFD and DEM. The measurements show that a Karman vortex field forms behind the obstacle and particles move inside this field with an average negative velocity of up to 25% of the fully developed velocity field. A comparison of CFD and DEM results with experimental data showed that in Karman velocity field, the CFD results fit better to the LDA measurements. In the fully developed flow region and also above and under the vortex field behind the obstacle, the DEM results match better with the LDA data.

Aerosols represent a health risk since small droplets may enter the respiratory system and cause lung cancer, allergies, or diseases like COVID-19. In this work, an Eulerian-Lagrangian computational fluid dynamics model is used based on a voxel-based (GeoDict) and a mesh-based (StarCCM+) code. For evaluating accuracy and computational time of both models, fractional filtration efficiency and pressure drop are compared to an empirical solution for a single fiber and to experimental results for a complex 3D fibrous filter material. Simulation results of both methods are in good agreement with empirical and measurement results although the complex geometry of the fibers is captured more accurately by the unstructured mesh using the same resolution. Computing times are much faster using the voxel-based code.