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Investigating the effect of compression on the permeability of fibrous porous media

Thesis (MSc)--Stellenbosch University, 2014.

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Main Author: Van Heyningen, Martha Catharina
Other Authors: Woudberg, Sonia
Format: Thesis
Language:en_ZA
Published: Stellenbosch : Stellenbosch University 2014
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access_status_str Open Access
author Van Heyningen, Martha Catharina
author2 Woudberg, Sonia
author_browse Van Heyningen, Martha Catharina
Woudberg, Sonia
author_facet Woudberg, Sonia
Van Heyningen, Martha Catharina
author_sort Van Heyningen, Martha Catharina
collection Thesis
dc_rights_str_mv Stellenbosch University
description Thesis (MSc)--Stellenbosch University, 2014.
format Thesis
id oai:scholar.sun.ac.za:10019.1/86245
institution Stellenbosch University (South Africa)
language en_ZA
last_indexed 2026-06-10T12:41:31.332Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository
publishDate 2014
publishDateRange 2014
publishDateSort 2014
publisher Stellenbosch : Stellenbosch University
publisherStr Stellenbosch : Stellenbosch University
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source_str SUNScholar — Stellenbosch University Repository
spelling oai:scholar.sun.ac.za:10019.1/86245 Investigating the effect of compression on the permeability of fibrous porous media Van Heyningen, Martha Catharina Woudberg, Sonia Stellenbosch University. Faculty of Science. Dept. of Mathematical Sciences. Porous materials -- Permeability Porous materials -- Compression testing Dissertations -- Applied mathematics Theses -- Applied mathematics Thesis (MSc)--Stellenbosch University, 2014. ENGLISH ABSTRACT: Fluid flow through porous media plays an important role in a variety of contexts of which filtration is one. Filtration efficiency of fibrous filters depends on the micro-structural characterization of these porous materials and is reflected in the permeability there-of. Compression of fibrous porous media has a significant effect on the permeability. Experimental data indicate that the permeability varies generally with more than an order of magnitude over the narrow porosity range in which the compression takes place. Relative to the amount of experimental studies regarding this phenomenon, there is a scarcity of geometric models in the literature that can account for the effect of compression on the permeability of a fibrous porous medium. Within the context of existing geometric porescale models based on rectangular geometry, a new model is presented and an existing model improved to predict the effect of one-dimensional compression in the streamwise direction. In addition, without compromising on a commitment to mathematical simplicity, empirical data of a non-woven fibrous porous medium was used to highlight the effect of model geometry on its predictive capability. Different mathematical expressions for the relationship between compression and porosity were considered. The permeability is expressed explicitly in terms of the fibre diameter and the compression fraction and implicitly in terms of the porosity. The porosity is incorporated through the relationship between the linear dimensions of the geometric model. The general applicability of the model(s) was validated by making use of data on airflow through a soft fibrous porous material as well as through glass and nylon fibres. The permeability predictions fall within the same order of magnitude as the experimental data. Given the mathematical simplicity of the model(s), the prediction capability is satisfactory. Attention is drawn to assumptions made and model restrictions within the analytical modelling procedure. A general predictive equation is presented for the permeability prediction in which a solid distribution factor is introduced. The proposed models serve as basis for further adaptation and refinement towards prediction capability. AFRIKAANSE OPSOMMING: Vloei van vloeistowwe deur poreuse media speel ’n belangrike rol in ’n verskeidenheid kontekste waarvan filtrasie een is. Die filtrasie doeltreffendheid van vesel filters hang af van die mikro-strukturele karakterisering van hierdie poreuse materiale en word gereflekteer in die permeabiliteit. Kompressie van veselagtige poreuse media het ’n beduidende effek op die permeabiliteit. Eksperimentele data dui aan dat die verandering in permeabiliteit gewoonlik oor meer as ’n orde grootte strek oor die klein porositeitsinterval waarin die kompressie plaasvind. Relatief tot die aantal eksperimentele studies rakende hierdie verskynsel, is daar ’n tekort aan geometriese modelle in die literatuur wat die effek van kompressie op die permeabiliteit van veselagtige poreuse media in ag kan neem. Binne die konteks van bestaande geometriese kanaal-skaal modelle gebasseer op reghoekige geometrie, is ’n nuwe model voorgestel en ’n bestaande model verbeter om die effek van een-dimensionele kompressie in die stroomsgewyse rigting te voorspel. Sonder om die verbintenis tot wiskundige eenvoud prys te gee, is empiriese data van ’n nie-geweefde veselagtige poreuse medium gebruik om die effek van die geometrie van ’n model op sy voorspellingsvermo¨e uit te lig. Verskillende wiskundige uitdrukkings is oorweeg vir die verband tussen kompressie en porositeit. Die permeabiliteit is eksplisiet uitgedruk in terme van die veseldiameter en die kompressie breukdeel en implisiet in terme van die porositeit. Die porositeit is ge-inkorporeer deur die verhouding tussen die lineêre dimensies van die geometriese model. Die algemene toepaslikheid van die model(le) is gestaaf deur gebruik te maak van data oor lugvloei deur ’n sagte veselagtige poreuse materiaal sowel as deur glas en nylon vesels. Die voorspellings van die permeabiliteit val binne dieselfde groote orde as die eksperimentele data. Gegee die wiskundige eenvoud van die model(le), is die voorspellingsvermoë bevredigend. Aandag is gevestig op aannames wat gemaak is en modelbeperkings binne die analitiese modellerings prosedure. ’n Algemene voorspellingsvergelyking is voorgestel vir die voorspelling van die permeabiliteit waarin ’n vaste stof distribusie faktor geinkorporeer is. Die voorgestelde modelle dien as basis vir verdere aanpassing en verfyning van voorspellingsvermoë. 2014-04-16T17:28:23Z 2014-04-16T17:28:23Z 2014-04 Thesis http://hdl.handle.net/10019.1/86245 en_ZA Stellenbosch University 109 p. : ill. application/pdf Stellenbosch : Stellenbosch University
spellingShingle Porous materials -- Permeability
Porous materials -- Compression testing
Dissertations -- Applied mathematics
Theses -- Applied mathematics
Van Heyningen, Martha Catharina
Investigating the effect of compression on the permeability of fibrous porous media
title Investigating the effect of compression on the permeability of fibrous porous media
title_full Investigating the effect of compression on the permeability of fibrous porous media
title_fullStr Investigating the effect of compression on the permeability of fibrous porous media
title_full_unstemmed Investigating the effect of compression on the permeability of fibrous porous media
title_short Investigating the effect of compression on the permeability of fibrous porous media
title_sort investigating the effect of compression on the permeability of fibrous porous media
topic Porous materials -- Permeability
Porous materials -- Compression testing
Dissertations -- Applied mathematics
Theses -- Applied mathematics
url http://hdl.handle.net/10019.1/86245
work_keys_str_mv AT vanheyningenmarthacatharina investigatingtheeffectofcompressiononthepermeabilityoffibrousporousmedia