Fraunhofer Institute for Industrial Mathematics ITWM Hall 7 / L1

Exhibitor Profile

Das Fraunhofer ITWM besitzt langjährige Erfahrung in der Modellierung und Simulation von Filtrations- und Separationsprozessen.

Das Anwendungsspektrum der Simulationstools und -dienstleistungen umfasst die Optimierung von Filtermedien und –elementen (u.a. Effizienz, Standzeit), von Feldflussfraktionierungsprozessen sowie die rechnergestützte Untersuchung von reaktiven Strömungen in porösen Medien.

Mithilfe der Computermodelle und Simulationen können neue Produkte bereits während der Auslegungsphase auf ihre Leistungsfähigkeit untersucht werden. Dadurch reduziert sich die Anzahl der zeit- und kostenaufwändigen Tests an Prototypen zum Teil erheblich.

Fraunhofer ITWM has years of experience in the modelling and simulation of filtration, separation and purification processes.

The software solutions and simulation services include the optimization of filter media and elements (efficiency, lifetime), field flow fractionation in microfluidics and the prediction of reactive flow in porous media.

The computer models and simulation tools enable the designer to investigate the performance of new products early in the developmental stage. Therefore, the number of time-consuming and costly tests with prototypes can be significantly reduced.

Products / Markets

Product Index

  • Absorptionsfilter
  • Automobilfilter
  • Filterelemente
  • Filtergehäuse
  • Filtermedien
  • Filterpatronen
  • Kraftstoff-Filter
  • Luftfilter
  • Medizinische Filter
  • Membranen
  • Simulation
  • Synthetische Fasern
  • Technische Textilien
  • Ultrafiltration
  • Umkehrosmose
  • Vliesmaterialien
  • Wasserfilter
  • Ölfilter

Market Scope

  • Abwasserwirtschaft
  • Automobilindustrie
  • Chemische Industrie
  • Farben-, Pigment-, Beschichtungsindustrie
  • Filtrations- und Separationsindustrie
  • Kunststoffverarbeitende Industrie
  • Lebensmittel-,Getränkeindustrie
  • Pharmazeutische Industrie
  • Textilindustrie
  • Zellstoff-, Papierindustrie

Product Index

  • Absorption Filters
  • Air Filters
  • Automotive Filters
  • Filter Cartridges
  • Filter Elements
  • Filter Housings
  • Filter Media
  • Fuel Filters
  • Medical Filters
  • Membranes
  • Nonwovens
  • Oil Filters
  • Reverse Osmosis
  • Simulation
  • Synthetic Fibres
  • Technical Textiles
  • Ultrafiltration
  • Water Filters

Market Scope

  • Automotive Industry
  • Chemical Industries
  • Filtration and Separation Industry
  • Food, Beverage Industry
  • Paint, Pigments, Coatings Industry
  • Pharmaceutical Industry
  • Plastic Industry
  • Pulp, Paper Industry
  • Textile Industry
  • Waste Water Treatment

Product Index

  • 医用过滤器
  • 反渗透
  • 合成纤维
  • 吸附式过滤器
  • 工业用纺织品
  • 无纺布
  • 模拟
  • 水过滤器
  • 汽车过滤器
  • 滤壳
  • 滤油器
  • 滤筒
  • 滤芯
  • 燃油过滤器
  • 空气过滤器
  • 超过滤
  • 过滤介质
  • 隔膜

Market Scope

  •  汽车工业
  • 制药工业
  • 化学工业
  • 塑料工业
  • 废水处理
  • 油漆、颜料、涂料工业
  • 纸浆、造纸工业
  • 纺织工业
  • 过滤与分离工业
  • 食品、饮料工业

Product Index

  • أقمشة تقنية
  • اسطوانات
  • الألياف الاصطناعية وسائل الإعلام
  • الفلترة المضاعفة
  • النضح العكسي
  • تصفية العلب
  • خراطيش فلتر
  • غير المنسوجات / اللانسيج
  • فلاتر إمتصاص
  • فلاتر السيارات
  • فلاتر الهواء
  • فلاتر زيوت
  • فلاتر طبية
  • فلاتر ماء
  • قطع فلاتر
  • محاكاة
  • مواد فلاتر المحروقات
  • مواد فلترة

Market Scope

  • الصناعات الدوائية
  • الصناعات الغذائية وصناعة المشروبات
  • الصناعة الكيماوية
  • الصناعة النسيجية
  • الصناعة الورقية
  • صناعات الفلترة وفصل المواد
  • صناعة البلاستيك
  • صناعة الدهانات والصبغات والتلبيس
  • صناعة السيارات
  • معالجة مياه الصرف

Product Index

  • Cartouches de filtres
  • Eléments de filtre
  • Fibres Synthétiques
  • Filtres automobiles
  • Filtres médicaux
  • Filtres à absorption
  • Filtres à air
  • Filtres à carburant
  • Filtres à eau
  • Filtres à huile
  • Les boîtiers de filtre
  • Membranes
  • Médias de filtre
  • Non tissés
  • Osmose inversée
  • Simulation
  • Textiles techniques
  • Ultrafiltration

Market Scope

  • Industrie automobile
  • Industrie chimique
  • Industrie de filtration et de séparation
  • Industrie de la pâte de cellulose et du papier
  • Industrie de peintures, pigments et revêtements
  • Industrie des matières synthétiques
  • Industrie pharmaceutique
  • Industrie textile
  • Industries alimentaires et des boissons
  • Traitement des eaux usées

Product Index

  • Alloggiamenti filtro
  • Cartucce filtri
  • Elementi filtranti
  • Fibra sintetica
  • Filtri aria
  • Filtri carburante
  • Filtri di assorbimento
  • Filtri medicali
  • Filtri olio
  • Filtri per acqua
  • Filtri settore automobilistico
  • Membrane
  • Mezzi filtranti
  • Non tessuti
  • Osmosi inversa
  • Simulazione
  • Tessuti tecnici
  • Ultrafiltrazione

Market Scope

  • Settore alimenti e bevande
  • Settore automobilistico
  • Settore chimico
  • Settore filtrazione e separazione
  • Settore industria dell carta e della cellulosa
  • Settore industria tessile
  • Settore parafarmaceutico
  • Settore pitture, pigmenti e rivestimenti
  • Settore plastica
  • Trattamento acque reflue

Product Index

  • Elementy filtra
  • Filtry absorbcyjne
  • Filtry do wody pitnej
  • Filtry do zastosowań medycznych
  • Filtry oleju
  • Filtry paliwa
  • Filtry powietrza
  • Filtry samochodowe
  • Materiały nietkane
  • Media filtrów
  • Membrany
  • Obudowy filtrów
  • Odwrócona osmoza
  • Symulacja
  • Tekstylia techniczne
  • Ultrafiltracja
  • Wkłady filtra
  • Włókno syntetyczne

Market Scope

  • Filtrowanie i separacja
  • Oczyszczanie ścieków (waste water)
  • Produkcja farb i lakierów
  • Przemysł celulozowo-papierniczy
  • Przemysł chemiczny
  • Przemysł farmaceutyczny
  • Przemysł samochodowy
  • Przemysł spożywczy
  • Przemysł tekstylny
  • Przemysł tworzyw sztucznych

Product Index

  • Carcaças de Filtro
  • Cartuchos filtrantes
  • Elementos filtrantes
  • Fibres Synthétiques
  • Filtros de absorção
  • Filtros de ar
  • Filtros de combustível
  • Filtros de água
  • Filtros de óleo
  • Filtros medicinais
  • Filtros para automóveis
  • Meios de filtragem
  • Membranas
  • Não-tecidos
  • Osmose inversa
  • Simulação
  • Têxteis para usos técnicos
  • Ultrafiltração

Market Scope

  • Indústria alimentar, de bebidas
  • Indústria automóvel
  • Indústria de filtragem e separação
  • Indústria dos plásticos
  • Indústria farmacêutica
  • Indústria têxtil
  • Indústrias químicas
  • Pasta, indústria do papel
  • Pintura, pigmentos, indústria de revestimentos
  • Tratamento de água de despejo

Product Index

  • Абсорбционный фильтр
  • Автомеханические фильтры
  • Водяные фильтры
  • Воздушные фильтры
  • Имитация
  • Корпуса фильтров
  • Масляные фильтры
  • Медицинские фильтры
  • Мембраны
  • Нетканые материалы
  • Обратный осмос
  • Синтетические волокна
  • Технический текстиль
  • Топливные фильтры
  • Ультрафильтрация
  • Фильтрующие патроны
  • Фильтрующие элементы
  • Фильтрующий материал

Market Scope

  • Автомобильная промышленность
  • Бумажная промышленность
  • Лакокрасочная промышленность
  • Отрасль фильтрации и сепарирования
  • Очистка сточных вод
  • Производство пластмасс
  • Производство продуктов питания и напитков
  • Текстильная промышленность
  • Фармацевтическая промышленность
  • Химическая промышленность

Product Index

  • Cartuchos de filtro
  • Elementos de filtro
  • Fibra Sintética
  • Filtro de Viviendas
  • Filtros de absorción
  • Filtros de aceite
  • Filtros de agua
  • Filtros de aire
  • Filtros de automoción
  • Filtros de combustible
  • Filtros médicos
  • Medios de filtro
  • Membranas
  • Non-Wowens
  • Osmosis inversa
  • Simulación
  • Tejidos técnicos
  • Ultrafiltración

Market Scope

  • Industria de la alimentación y las bebidas
  • Industria de la automoción
  • Industria de la filtración y la separación
  • Industria de la pasta de madera, el papel
  • Industria de las pinturas, pigmentos, revestimientos
  • Industria de los plásticos
  • Industria farmacéutica
  • Industria textil
  • Industrias químicas
  • Tratamiento de aguas residuales

Product Index

  • Absorpsiyon Filtreleri
  • Dokunmamış Mamuller
  • Filtre Elemanları
  • Filtre Gövdeleri
  • Filtre Kartuşları
  • Filtre Ortamı
  • Hava Filtreleri
  • Membranlar
  • Otomobil Filtreleri
  • Sentetik Elyaf
  • Simülasyon
  • Su Filtreleri
  • Teknik Tekstiller
  • Ters Ozmos
  • Tıbbi Filtreler
  • Ultrafiltrasyon
  • Yakıt Filtreleri
  • Yağ Filtreleri

Market Scope

  • Atıksu Arıtma
  • Boya, Pigment, Kaplama Endüstrisi
  • Filtrasyon ve Ayırma Endüstrisi
  • Gıda, İçecek Endüstrisi
  • Kimya Endüstrisi
  • Otomotiv Endüstrisi
  • Plastik Endüstrisi
  • Selüloz, Kağıt Endüstrisi
  • Tekstil Endüstrisi
  • İlaç Endüstrisi

Product Index

  • 공기 필터
  • 기능성 섬유
  • 물 필터
  • 부직포
  • 분리막
  • 시뮬레이션
  • 여과재
  • 역삼투
  • 연료 필터
  • 오일 필터
  • 의료 필터
  • 자동차 필터
  • 필터 엘리먼트
  • 필터 카트리지
  • 필터 하우징
  • 한외 여과
  • 합성섬유
  • 흡수 필터

Market Scope

  • 섬유 산업
  • 식음료 산업
  • 여과 및 분리 산업
  • 자동차 산업
  • 제약 산업
  • 제지, 종이 산업
  • 페인트, 안료, 도장 산업
  • 폐수 처리
  • 플라스틱 산업
  • 화학 산업

Product Index

  • エアフィルター
  • オイルフィルター
  • シミュレーション
  • テクニカル繊維
  • フィルターエレメント
  • フィルターカートリッジ
  • フィルターハウジング
  • フィルターメディア
  • 不織布
  • 医療用フィルター
  • 合成繊維
  • 吸収フィルター
  • 水フィルター
  • 燃料フィルター
  • 自動車用フィルター
  • 逆浸透
  • 限外濾過

Market Scope

  • パルプ、製紙業界
  • プラスチック業界
  • 化学工業
  • 医薬品業界
  • 塗料、顔料、コーティング産業
  • 汚水処理
  • 濾過および分離技術工業
  • 繊維業界
  • 自動車産業
  • 食品、飲料業界

Press release

ITWM bietet simulationsbasierte Lösungen für Filtrationsanwendungen

ITWM bietet simulationsbasierte Lösungen für Filtrationsanwendungen

Filter werden in vielen Bereichen der Industrie und des täglichen Lebens eingesetzt. Sie schützen Menschen vor toxischen oder allergenen Stoffen und erhalten die Funktionsfähigkeit von Maschinen. Vor allem müssen Filter an ihren jeweiligen Einsatzbereich angepasst sein. Reinraumfilter müssen selbst kleinste Staubpartikel aus der Luft filtern, Ölfilter hingegen müssen im Hinblick auf den Differenzdruck weitaus durchlässiger sein. Für jede Filtrationsanwendung existiert also eine ganz spezifische Lösung.

Konventionell werden Prototypen konstruiert und getestet. Dies ist sehr zeit- und kostenaufwändig, da sowohl die Filtereffizienz als auch die Aufnahmekapazität von Filtern durch das komplexe Zusammenspiel vieler Faktoren bestimmt werden. Zu den Faktoren zählen auf der Ebene der Filtermedien u.a. die physikalisch-chemischen und geometrischen Eigenschaften der Einzelfasern, die räumliche Anordnung der Fasern im Filtergewebe, die physikalisch-chemischen Eigenschaften der Flüssigkeit sowie Größe, Masse und Form der zu filternden Partikel. Auf der Ebene der Filterelemente sind u.a. die Gehäuseform, die Form der eingesetzten Filtermedien (z.B. gefaltet und/oder flach) und die Kombination verschiedenartiger Medien in einem Filterelement als interagierende Einflussfaktoren entscheidend für die Leistung des Bauteils.

Das Fraunhofer-Institut für Techno- und Wirtschaftsmathematik in Kaiserslautern entwickelte seit 2001 die Software GeoDict. Mit GeoDict können die Filtrationseigenschaften eines Filtermediums virtuell ermittelt werden. Die Mikrostruktur, die das Filtermedium in der Simulation repräsentiert, kann entweder virtuell nach Vorgabe bestimmter Spezifikationen erzeugt oder aus der Rekonstruktion von drei-dimensionalen Computertomografien realer Filter gewonnen werden. Durch eine speziell für komplexe Materialstrukturen entwickelte Strömungssimulation sind wichtige Eigenschaften wie z. B. die Permeabilität der Mikrostruktur ermittelbar. Das Modul FilterDict berücksichtigt die unterschiedlichen Filtrationsmechanismen für große und kleine Partikel und berechnet die Filtereffizienz sowie die Verteilung der Schmutzbeladung des Filters (Tiefen- und Kuchenfiltration). Durch Berücksichtigung des Strömungswiderstandes der abgelagerten Partikel kann der Differenzdruck bei Durchströmung des beladenen Mediums bestimmt werden. Die Mikrostruktur kann mit GeoDict auch verändert werden (virtuelles Materialdesign), was den Bedarf an aufwändigen Tests mit real erzeugten Medien reduziert. Seit Januar 2013 wird GeoDict von der Math2Market GmbH, einer Ausgründung des Fraunhofer ITWM, weiterentwickelt und vermarktet.

Seit 2002 entwickelt das Fraunhofer ITWM Modelle und numerische Methoden, die Ingenieure bei der Auslegung des gesamten Filterelements unterstützt. Diese Kenntnisse und Erfahrungen sind nun in FiltEST, der Filter Element Simulation Toolbox, gebündelt worden. FiltEST versetzt die Entwickler von Filterelementen in die Lage, frühzeitig und zuverlässig Qualität und Leistungsfähigkeit eines Designs einzuschätzen. Die Software beinhaltet u.a. Module zum Importieren von CAD-Geometrien und Berechnungsmodule für die Vorhersage des Strömungsfeldes, der Filtrationseffizienz sowie der Differenzdruckentwicklung bei Beladung. Die Simulationsergebnisse werden in Datenformate für die effektive 3D-Visualisierung und weitere Post-Processing-Schritte exportiert.

GeoDict und FiltEST können auch miteinander gekoppelt eingesetzt werden, so dass die Simulation von Filtrationsprozessen auch das komplexe Zusammenspiel von Effekten auf der Mikro- und der Makroskalenebene widerspiegelt. GeoDict und FiltEST sind deshalb wesentliche Schritte in Richtung des virtuellen Designs von Filterelementen und -medien.

In praktischen Anwendungen werden die strukturmechanischen Eigenschaften von Filtermedien immer relevanter. Für die Mikrostruktur sind bereits Simulationswerkzeuge vorhanden, mit deren Hilfe die effektiven elastischen Eigenschaften eines Mediums aus den Daten des Fasermaterials berechnet werden können (FeelMath, ElastoDict). Diese Ergebnisse können dann für die Simulation der strömungsinduzierten Verformung des Mediums auf Gehäuseebene benutzt werden.

Das Fraunhofer ITWM präsentiert diese und viele andere Entwicklungen auf dem Gebiet der Filtration und Separation wieder auf der FILTECH 2018 in Köln, Stand A9.

Fraunhofer ITWM provides simulation solutions for Filtration applications

Fraunhofer ITWM provides simulation solutions for Filtration applications

Filters are used in many industries and daily life. They protect people from toxic or allergic substances and ensure operability of tools and machines. Filters must be adjusted to their operating conditions. Clean room filters must collect the tiniest particles. Oil filters must have a much lower flow resistivity. Every filtration application requires its own specific solution.

The traditional method is to build and test prototypes. This is time-consuming and expensive because key performance factor such as the pressure drop, filter efficiency, and filter capacity are governed by the complex interaction of many factors. On the microscopic level, such factors include the physical, chemical and geometric properties of fibers used in filter media, the spatial arrangement of the fibers in the filter media, the physical and chemical properties of the gas or liquid as well as size, mass and shape of dust particles. On the macroscopic scale of the entire filter element, the interplay between the shapes of the housing and the media (e.g. pleated or flat) the combination of different filtering media etc. is crucial to the performance of the final product.

Since 2001, the Fraunhofer Institute for Industrial Mathematics (ITWM) developed the GeoDict software. GeoDict predicts filtration properties based on three-dimensional models of the microstructure of filter media and direct numerical simulation of the relevant processes. The microstructure can be generated based on given specification of the filter media, or loaded into the software based on three-dimensional input data from computer tomography of the filter media. By use of a flow solver which is specialized in the treatment of complex microscopic structures, quantities such as the permeability of the medium can be determined. Based on the particle size distribution, the FilterDict module considers the different filtration mechanisms in order to compute the filtration efficiency and distribution of deposited particles, covering both the depth and the cake filtration stage. By taking into account the flow resistance due to the deposited dust, the increase in the pressure drop can be predicted by simulating the flow through the loaded medium. On top of that, GeoDict allows the user to edit the microstructure (virtual material design) and study the effect of the changes, leading to a substantial reduction of the time and cost usually spent on experimental testing of prototypes. Since January 2013, the Math2Market GmbH, a spin-off of Fraunhofer ITWM, continues the development and marketing of GeoDict.

Since 2002, the Fraunhofer ITWM has developed models and numerical methods which assist the engineers in the design of the entire filter element. This expertise has flown into FiltEST, the Filter Element Simulation Toolbox. FiltEST enables designers of filter elements to have a computer-aided assessment of the performance properties of an element’s design at a very early stage of the developmental process. It provides modules for importing CAD geometries, computing the flow field in the element, the filtration efficiency and the evolution of the differential pressure during the operation of the device. The simulation results are exported to file formats for effective 3D visualization and further post-processing.

FiltEST and GeoDict can be coupled such that the filtration process at both the micro- and the macro-scale can be simulated hand in hand, reflecting the complex interplay of phenomena occurring on the two scales. GeoDict and FIltEST are major cornerstones towards the virtual design of filter materials and filter elements.

In practical applications, the structural mechanics of filtering media has become more and more relevant. For the microscopic scale, there are simulation tools for the computation of effective elastic properties of filtering media, based on the data of the fiber material (FeelMath, ElastoDict). These results can be used to predict the flow-induced deformation of the filter media on the macroscopic scale of the element.

Fraunhofer ITWM will present these and many more developments in the area of filtration and separation again at the FILTECH 2018 in Cologne, Stand A9

Conference Presentation/s

Conference Session: L14 - Flotation-Adsorption-Coalescence /Using of Boundary Surface Effects

Microscale modelling and simulation of the removal of water from diesel fuel using hydrophobic separator meshes

S. Antonyuk, Technische Universität Kaiserslautern; O. Elsayed*, R. Kirsch, S. Osterroth, Fraunhofer Institute for Industrial Mathematics (ITWM), Germany

Liquid-liquid separation systems are vital for many applications: power generators, automotive, hydraulic lines, etc. In the special case of diesel fuel, the trend towards sustainable fuel production and reduction of hazardous emissions lead to the increasing usage of ultra-low-sulfur diesel and bio-diesel. Such fuels exhibit a significantly reduced the surface tension between the diesel and the inevitable water content, rendering the removal of the water more difficult. Consequently, the design of separators in diesel fuel filters meeting today’s performance requirements imposes a challenge to the developing engineer and suitable simulation techniques. Hence, in order to improve and further optimize the current separator systems, a better understanding of the influence of material parameters such as wettability and geometric properties of the mesh on the separation performance would be very useful.

The challenge in modeling and simulation of such systems is the fact that phenomena on different length scales influence each other:

On the microscale, individual droplets are considered. In the free flow region, they are much smaller than the hydrodynamic length scale and their motion is mainly due to the flow. After coalescence at the hydrophobic separator screen, gravitational forces are more and more dominant and separation by drainage occurs. Both coalescence and drainage influence how much of the mesh surface is open. On the macroscopic scale, this affects the over-all differential pressure and the distribution of the local flow speed near the mesh, which in turn changes the transport of the water droplets towards the mesh.

The present work is devoted to the modeling and simulation of the interaction between the water droplets and the separator screen taking into account the gravity forces in the microscale. It is seen that...


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Conference Session: F7 - Filter Media Development Supported by Simulation Methods I

Virtual production of filter media using simulation driven design

A. Schmeißer*, S. Gramsch, W. Arne, R. Wegener, Fraunhofer Institute for Industrial Mathematics (ITWM); F. J. Hahn, T. Gose, A. Koronai-Bauer, K. Riedinger, F. Keller, MANN+HUMMEL GmbH, Germany

The emission of fine dust from industrial processes and traffic as well as contamination-sensitive manufacturing technology and clean rooms call for the provision of clean indoor air and therefore requires highly efficient air filter media. Considering the rise in energy cost and the necessity of worldwide CO2 reduction the energy consumption of air filters becomes increasingly relevant. Developing filter media featuring both highest levels of filtration efficiency and lowest possible pressure drop poses an optimization challenge, as both design goals are conflicting.

The increased demand for high performance filters gives rise to challenging engineering tasks to develop efficient filters for different applications. An important aspect in the research and development of new filter media is virtual production with software simulation. A common approach for this models filters as fibrous media with given statistical properties. Using a simulation loop, these properties can be designed to yield optimal performance. However, this does not yet account for how a filter medium with the designed properties can be produced in an actual production process. Thus, the realization of virtually predicted optimal filter media prototypes requires extensive validation in trial runs and may sometimes not be achievable.

We aim to address this issue by means of a novel, holistic approach to the virtual media development. Within the scope of a publicly funded research project, we develop a simulation chain for the simulation-driven design of new filter media demonstrated exemplary using the spunblown process.

Our coupled approach uses a complex chain for the complete simulation from the production process to the final product and its filtration properties, along with a validation of results using experiments on the corresponding real filter media. Instead of the conventional parametric material model of the resulting filter media, we use a fully physical model of the production process starting from the spinning of filaments at the spinneret, down to the stretching in turbulent airflow and web forming of the nonwoven material. The visco-elastic material models used can...


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Conference Session: F8 - Filter Media Development supported by Simulation Methods II

Flow-induced deformation of filter media - part 2: modeling and simulation

R. Kirsch*, R. Deshpande, Fraunhofer Institute for Industrial Mathematics (ITWM); S. Antonyuk, V. Puderbach, Technische Universität Kaiserslautern, Germany

The majority of simulation models for filter elements assume that the filter media are “rigid bodies”. In reality however, it is observed that the fluid flow causes deformations which can lead to well-known (and undesired) effects like pleat collapse, pleat crowding etc.

Several works were devoted to the development of models and methods to take into account this Fluid-Porous-Structure Interaction (FPSI) in order to obtain more realistic simulation results. By nature, the earlier studies focused on liquid filtration applications, of which only few are mentioned here: In [1], an effective permeability approach was used for an improved prediction of the relationship between pressure drop and flow rate in pleated cartridges. A coupling of flow and structural mechanics simulation based on Stokes-Brinkman equations and hyperelastic porous materials in three dimensions in space was presented in [2]. Taber’s model for poroelastic plates was the starting point for the numerical simulation (two-dimensional in space) and experimental validation of small flow-induced deformations in [3]. Deformations of filter media are observed in air filtration, too. In [4], a coupled simulation (two-dimensional in space) of the deformation of pleats in cabin air filters was studied.

The aim of the present work is to extend the applicability of the coupled simulations for liquid filtration at constant flow rates in a way that the simulations will be done in 3D, include faster flow regimes (Navier-Stokes-Brinkman) and allow for larger deformations and non-linear elasticity...


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Conference Session: G10 - Respiratory Masks I

Modeling and simulation of moisture penetration and wearing time of face masks

M. Böhle, A. Schwarzwälder, Technische Universität Kaiserslautern; R. Kirsch, S. Osterroth* , Fraunhofer Institute for Industrial Mathematics (ITWM), Germany

The year 2020 has shown an increasing awareness of the use of face masks and respirators in order to protect the wearer or the surrounding people against infections.

Two protection concepts can be distinguished: self-protection and external protection. In the first concept, the wearer wants to protect himself or herself against infectious pathogens or viruses in the surrounding. Depending on the availability, corresponding filter masks should be preferably used by people working in health and nursing care. In the second concept, the wearer protects people in the surrounding from being infected.

A reliable protection does not only depend on the filtration properties of the mask material. In the literature, it is discussed whether moisture penetration decreases the filtering efficiency [1, 2]. If this is the case, the safety is reduced [3]. The most critical state is reached when the mask is imbrued entirely (moisture breakthrough) since the moisture can serve as an "infection bridge" spanning across the depth of the filter material. This holds for highly efficient filter masks (e.g. FFP-2), but even more so for masks to protect others: Coughing and sneezing can lead to the detachment of potentially infectious droplets from the outer surface, which will then spread into the vicinity [2]. In standard test procedures such as DIN EN 14683 [4], DIN EN 149 [5], or 42 CFR Part 84 [6], the temperature and the moisture content are considered as constant and static. The test material is adjusted to given conditions. However, when breathing out, the face mask is exposed to moisture and the temperature (body heat) is different from the surrounding.

Most wearing time recommendations are reference values, based on an average usage scenario. The speed and intensity of the moisture penetration of a mask depend heavily on the physical stress level of the wearing person [7, 8]. The time it takes until the moisture breaks through cannot be derived in a simple way ("rule of thumb") from the physical activity, which is usually fluctuating. In general, a visual check of the mask is neither feasible without aid nor reliable enough to detect a moisture breakthrough.

Specialized computer simulation tools have proven to be very useful for the innovation and optimization of filtration devices. Previous studies were mostly focused on filtration efficiency and have not considered the moisture transport. Additionally, the breathing behavior was modeled using an idealized sinusoidal profile.

The present work is devoted to the adaptation of well-known transport models to the transport of moisture in porous media...


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Conference Session: L8 - Backwashing Filtration

How programmable materials can be used to design woven filter media with optimized backwashing properties

R. Kirsch, S. Osterroth, S. Rief*, Fraunhofer Institute for Industrial Mathematics (ITWM), Germany

Global challenges such as sustainable development, climate change, renewable energy, or individual mobility increase the necessity for a much more efficient and sustainable use of our resources. Programmable materials have the potential to initiate a paradigm shift since they can perform system functions through their internal design. This allows for increased functional integration while simultaneously reducing system complexity. Programmable materials are materials whose inner structure is designed and manufactured in such a way that properties and behavior can be controlled and reversibly changed by external stimuli, e.g. temperature changes or chemical agents. Moreover, new manufacturing methods make it possible to specifically produce these structures in the micrometer range. These methods include for example, additive processes like 3D-printing.

In this paper, the focus is on the use of programmable materials in the area of effective filter cleaning. More precisely, we investigate weaves in a liquid filtration application. In the regular filtration step, it is desirable to have high filtration efficiencies, a low pressure drop and a high dust holding capacity. Low pressure corresponds to energy savings and low operating costs. The dust holding capacity ensures efficient use of operational capacity. When certain limits are reached, the backwashing step is performed to clean the filter medium from deposited dust. Thereby, the filter medium does not need to be replaced and maybe used several filtration cycles. However, backwashing cannot clean the medium entirely and the motivating question is: What is the potential to improve the backwashing efficiency by geometrical changes of the filter medium using programmable materials? Backwashing efficiency means short regeneration time, low clean water consumption and minimal particulate residues. We answer the above question by...


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