Senior Applications Specialist, Math2Market GmbH
Dr. Liping Cheng works as Senior Application Specialist at Math2Market Company, Germany. She obtained her PhD degree in Mechanical Engineering, major in Computational Fluid Dynamics, from North Carolina State University in 2004. In 2005 she joined Fraunhofer Institute for Industrial Mathematics in Kaiserslautern, Germany and the research interests are on the micro-structure simulations. In 2013 she joined the spin-off company, Math2Market, to develop and promote the material simulator software, GeoDict. Her work focus on the flow and filtration modeling and simulation in micro- and meso-scale.
The performance of filter media depends on choosing the raw materials and their micro structure, i.e. the distribution of the constituents, such as fibers, in space. The power of simple models is limited to predict the effects of the micro structure, as happens when overlooking the internal details of the filtration processes. μCT and FIB-SEM deliver 3D images of existing materials with unprecedented resolution. From these, the properties of the material can be computed to match measured properties. Computer models can also be converted into 3D images and, from these, material properties can be determined without the need to manufacture a prototype first.
Instead of letting universities or institutes develop next generation materials, companies keep this knowledge in-house, by letting their own employees run the digital experiments. However, the difficulty of the Math & Software Know-How is such that even the largest companies cannot do it all by themselves. Math2Market provides such a solution through the digital material laboratory, GeoDict®. This complete software package is used to analyze or design porous and composite materials based on the material's geometric inhomogeneity.
Simulations can be done on different scales. 3D models are made for filter media, pleats, and whole filters, where the media models could also result from μCT scans of existing media. Different types of filter media can be modeled, including cellulose, glass and synthetic fibers, ceramics, open cell foams, and weaves. On the models, GeoDict® can predict: pore size measures, pressure drop, flow resistivity, permeability, filter efficiency, and filter life time or dust holding capacity. The filtration process is simulated by following these steps: First, a stationary flow through the filter media is computed. Depending on the resolution, it is Stokes-flow or Darcy-Flow. Then, particles are introduced and moved according to friction with the fluid, inertia, and Brownian motion. Filtered particles are deposited on the filter material. Thus, later particles experience a different flow field, and can then be caught either by the filter material or the previously deposited particles. In this way, a filter cake forms. The whole process can be simulated using the FilterDict® module of the GeoDict® software. The simulation process is integrated automatically and the performance parameters are reported. Simulations, combined with experiments, can lead to new knowledge, such as understanding of re-entrainment, quantification of phenomena such as effects of layers, as well as patents and long-term commercial benefits. In the near future, companies must be on top of their materials. The days of trial-and-error are numbered, as powerful research tools deliver scientific data of unprecedented depth [http://www.economist.com/technology-quarterly/2015-12-05/new-materials-for-manufacturing]. At Math2Market, we truly believe that, in particular for filter media, the future has already begun!