New Approach for Determining Tortuosity in Fibrous Porous Media

A method to determine tortuosity in a fibrous porous medium is proposed. A new approach for sample preparation and testing has been followed to establish a relationship between air permeability and fiberweb thickness which formed the basis for the determination of tortuosity in fibrous porous media. An empirical relationship between tortuosity and fiberweb structural properties including porosity, fiber diameter and fiberweb thickness has been proposed unlike the models in the literature which have expressed tortuosity as a function of porosity only. Transverse air flow through a fibrous porous media increasingly becomes less tortuous with increasing porosity, with the value of tortuosity approaching 1 at upper limits of porosity. Tortuosity also decreased with increase in fiber diameter whereas increase in fiberweb thickness resulted in the increase in tortuosity within the range of fiberweb thickness tested.

[1]  C. N. Davies.  The Separation of Airborne Dust and Particles , 1950 .

[2]  L. A. Clarenburg,et al.  Aerosol filters—the tortuosity factor in fibrous filters , 1967 .

[3]  Jacques Comiti,et al.  A new model for determining mean structure parameters of fixed beds from pressure drop measurements: application to beds packed with parallelepipedal particles , 1989 .

[4]  S. Rigby,et al.  NMR and fractal modelling studies of transport in porous media , 1996 .

[5]  Bernard P. Boudreau,et al.  The diffusive tortuosity of fine-grained unlithified sediments , 1996 .

[6]  A. Hoekstra,et al.  Permeability of Three-Dimensional Random Fiber Webs , 1998 .

[7]  W. Lauriks,et al.  Direct and inverse scattering of transient acoustic waves by a slab of rigid porous material. , 2003, The Journal of the Acoustical Society of America.

[8]  Ravi J. Suman,et al.  Formation factor and tortuosity of homogeneous porous media , 1993 .

[9]  P. Grathwohl,et al.  Tracer diffusion coefficients in sedimentary rocks: correlation to porosity and hydraulic conductivity. , 2001, Journal of contaminant hydrology.

[10]  Yu Bo-Ming,et al.  A Geometry Model for Tortuosity of Flow Path in Porous Media , 2004 .

[11]  M. M. Tomadakis,et al.  Viscous Permeability of Random Fiber Structures: Comparison of Electrical and Diffusional Estimates with Experimental and Analytical Results , 2005 .

[12]  Drona Kandhai,et al.  Simulations of Single-Fluid Flow in Porous Media , 1998 .

[13]  Xenon NMR measurements of permeability and tortuosity in reservoir rocks. , 2004, Magnetic resonance imaging.

[14]  P. Schjønning,et al.  Tortuosity, diffusivity, and permeability in the soil liquid and gaseous phases , 2001 .

[15]  A. Garrouch,et al.  Using diffusion and electrical measurements to assess tortuosity of porous media , 2001 .

[16]  P. M. Heertjes,et al.  Analysis of diffusion in macroporous media in terms of a porosity, a tortuosity and a constrictivity factor , 1974 .

[17]  S. V. Sotirchos,et al.  Ordinary and transition regime diffusion in random fiber structures , 1993 .

[18]  Hans-Jörg Vogel,et al.  Morphological determination of pore connectivity as a function of pore size using serial sections , 1997 .

[19]  Yun Mei-Juan,et al.  A Geometry Model for Tortuosity of Streamtubes in Porous Media with Spherical Particles , 2005 .