Download or read book Multi component Acoustic Characterization of Porous Media written by Karel Nicolaas van Dalen and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multi Component Acoustic Characterization of Porous Media written by Karel N. van Dalen and published by Springer Science & Business Media. This book was released on 2013-01-11 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: The feasibility to extract porous medium parameters from acoustic recordings is investigated. The thesis gives an excellent discussion of our basic understanding of different wave modes, using a full-waveform and multi-component approach. Focus lies on the dependency on porosity and permeability where especially the latter is difficult to estimate. In this thesis, this sensitivity is shown for interface-wave and reflected-wave modes. For each of the pseudo-Rayleigh and pseudo-Stoneley interface waves unique estimates for permeability and porosity can be obtained when impedance and attenuation are combined. The pseudo-Stoneley wave is most sensitive to permeability: both the impedance and the attenuation are controlled by the fluid flow. Also from reflected-wave modes unique estimates for permeability and porosity can be obtained when the reflection coefficients of different reflected modes are combined. In this case the sensitivity to permeability is caused by subsurface heterogeneities generating mesoscopic fluid flow at seismic frequencies. The results of this thesis suggest that estimation of in-situ permeability is feasible, provided detection is carried out with multi-component measurements. The results of this thesis argely affect geotechnical and reservoir engineering practices.
Download or read book Acoustics of Porous Media written by Thierry Bourbié and published by Editions TECHNIP. This book was released on 1987 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Propagation of Sound in Porous Media written by J.F. Allard and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book has grown out of the research activities of the author in the fields of sound propagation in porous media and modelling of acoustic materials. It is assumed that the reader has a background of advanced calculus, including an introduction to differential equations, complex variables and matrix algebra. A prior exposure to theory of elasticity would be advantageous. Chapters 1-3 deal with sound propagation of plane waves in solids and fluids, and the topics of acoustic impedance and reflection coefficient are given a large emphasis. The topic of flow resistivity is presented in Chapter 2. Chapter 4 deals with sound propagation in porous materials having cylindrical pores. The topics of effective density, and of tortuosity, are presented. The thermal exchanges between the frame and the fluid, and the behaviour of the bulk modulus of the fluid, are described in this simple context. Chapter 5 is concerned with sound propagation in other porous materials, and the recent notions of characteristic dimensions, which describe thermal exchanges and the viscous forces at high frequencies, are introduced. In Chapter 6, the case of porous media having an elastic frame is considered in the context of Biot theory, where new topics described in Chapter 5 have been included.
Download or read book Characterization of Porous Media by Frequency Response Analysis written by Kwang-Kuk Koh and published by . This book was released on 1968 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multiphysics in Porous Materials written by Zhen (Leo) Liu and published by Springer. This book was released on 2018-07-12 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarizes, defines, and contextualizes multiphysics with an emphasis on porous materials. It covers various essential aspects of multiphysics, from history, definition, and scope to mathematical theories, physical mechanisms, and numerical implementations. The emphasis on porous materials maximizes readers’ understanding as these substances are abundant in nature and a common breeding ground of multiphysical phenomena, especially complicated multiphysics. Dr. Liu’s lucid and easy-to-follow presentation serve as a blueprint on the use of multiphysics as a leading edge technique for computer modeling. The contents are organized to facilitate the transition from familiar, monolithic physics such as heat transfer and pore water movement to state-of-the-art applications involving multiphysics, including poroelasticity, thermohydro-mechanical processes, electrokinetics, electromagnetics, fluid dynamics, fluid structure interaction, and electromagnetomechanics. This volume serves as both a general reference and specific treatise for various scientific and engineering disciplines involving multiphysics simulation and porous materials.
Download or read book Investigation of Inverse Acoustical Characterization of Porous Materials Used in Aircraft Noise Control Application written by Apoorv Ravindran and published by . This book was released on 2007 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sound propagation through porous media such as foams and fibers is governed by five parameters that describe the geometry of the porous frame: porosity, tortuosity, flow resistivity, viscous characteristic length, and thermal characteristic length. The conventional laboratory methods for measuring these geometric properties are prone to errors and can be highly cumbersome. In this work, an alternative method of determining the geometric properties of porous materials, based on an inverse acoustical technique, was investigated for materials used in aircraft noise-control applications. This technique is incorporated in commercial software codes, such as FOAM-X (ESI Group) and Comet TrimTM (Comet Acoustics), which require the absorption coefficient and/or transmission loss (TL) to be measured in Brüel and Kjær (or equivalent) standing wave tubes as inputs. The estimated geometric properties are required to define the porous material for complex vibroacoustic analysis in commercial code such as AutoSEA2 (ESI Group). One of the goals of this work was to evaluate the accuracy of the estimated geometric properties. A closed-loop validation technique was previously developed where the absorption coefficient and transmission loss were predicted using AutoSEA2 and compared with the standing wave tube measurements. Good agreement between the measured and predicted absorption coefficient was observed for both foams and fibers. However, in the case of transmission loss, good agreement was observed for fibers but not for foams. In order to eliminate inconsistencies, the existing validation loop was modified by incorporating Comet TrimTM inverse characterization software that took both the normal incidence absorption coefficient and transmission loss as sequential inputs to estimate the geometric properties. To complete the modified loop, sound absorption and transmission loss of porous materials was predicted using the performance analysis module in Comet TrimTM and compared with the test results. In general, the absorption coefficient of most of the foams and fibers, prediction using both validation loops was in good correlation with the measured data. On the other hand, the correlation in normal incidence transmission loss was better using the modified loop. In the process of investigating the repeatability of estimating the physical properties, previously measured porous material samples were re-measured for their absorption coefficient and transmission loss. A possible effect of sample aging was discovered and reported. As an alternate method to the forward TL calculation, a finite element model of the standing wave tube was also developed. This could be used to study the effect of boundary conditions on acoustic properties. Finally, individually validated samples were combined to develop optimized multilayer aircraft noise-control treatments and were experimentally demonstrated to produce excellent acoustical performance.
Download or read book Pore Scale Characterization of Displacement Front Dynamics in Porous Media written by Franziska Möbius and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Kinetic and Continuum Theories of Granular and Porous Media written by Kolumban Hutter and published by Springer. This book was released on 2014-05-04 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an account on the thermomechanical behaviour of granular and porous materials and deals with experiments, theoretical deduction of macroscale equations by means of averaging from microscale properties, embedding the macroscopic description into a continuum-thermodynamical and statistical context and analysis of solutions of macroscopic models by numerical techniques. It addresses itself to engineers (chemical, civil, mechanical) applied mathematicians and physicists at the advanced student or Ph. D. level at universities, research centres and in industry.
Download or read book Characterization of Porous Media by Miscible Displacement written by Josia C. Kana and published by . This book was released on 1964 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Propagation of Sound in Porous Media written by J.F. Allard and published by Springer. This book was released on 2012-01-07 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book has grown out of the research activities of the author in the fields of sound propagation in porous media and modelling of acoustic materials. It is assumed that the reader has a background of advanced calculus, including an introduction to differential equations, complex variables and matrix algebra. A prior exposure to theory of elasticity would be advantageous. Chapters 1-3 deal with sound propagation of plane waves in solids and fluids, and the topics of acoustic impedance and reflection coefficient are given a large emphasis. The topic of flow resistivity is presented in Chapter 2. Chapter 4 deals with sound propagation in porous materials having cylindrical pores. The topics of effective density, and of tortuosity, are presented. The thermal exchanges between the frame and the fluid, and the behaviour of the bulk modulus of the fluid, are described in this simple context. Chapter 5 is concerned with sound propagation in other porous materials, and the recent notions of characteristic dimensions, which describe thermal exchanges and the viscous forces at high frequencies, are introduced. In Chapter 6, the case of porous media having an elastic frame is considered in the context of Biot theory, where new topics described in Chapter 5 have been included.
Download or read book Acoustic and Thermal Properties of Recycled Porous Media written by Sararat Mahasaranon and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is concerned with developing porous materials from tyre shred residue and polyurethane binder for acoustic absorption and thermal insulation applications. The resultant materials contains a high proportion of open, interconnected cells that are able to absorb incident sound waves through viscous friction, inertia effects and thermal energy exchanges. The materials developed are also able to insulate against heat by suppressing the convection of heat and reduced conductivity of the fluid locked in the large proportion of close-cell pores. The acoustic absorption performance of a porous media is controlled by the number of open cells and pore size distribution. Therefore, this work also investigates the use of catalysts and surfactants to modify the pore structure and studies the influence of the various components in the chemical formulations used to produce these porous materials. An optimum type and amounts of catalyst are selected to obtain a high chemical conversion and a short expanding time for the bubble growth phase. The surfactant is used to reduce the surface tension and achieve a homogenous mixing between the solid particulates tyre shred residue, the water, the catalyst and the binder. It is found that all of the components significantly affect the resultant materials structure and its morphology. The results show that the catalyst has a particularly strong effect on the pore structure and the ensuing thermal and acoustical properties. In this research, the properties of the porous materials developed are characterized using standard experimental techniques and the acoustic and thermal insulation performance underpinned using theoretical models. The important observation from this research is that a new class of recycled materials with pore stratification has been developed. It is shown that the pore stratification can have a positive effect on the acoustic absorption in a broadband frequency range. The control of reaction time in the foaming process is a key function that leads to a gradual change in the pore size distribution, porosity, flow resistivity and tortuosity which vary as a function of sample depth. It is shown that the Pade approximation is a suitable model to study the acoustic behaviour of these materials. A good agreement between the measured data and the model was attained.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of Porous Material Used for Thermoacoustic Devices written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustics Elasiticity and Thermodynamics of Porous Media Twenty One Papers written by M.A. Biot and published by American Institute of Physics. This book was released on 1992-03-31 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Poromechanics written by J.F. Thimus and published by CRC Press. This book was released on 1998-01-01 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text features 105 papers dealing with the fundamentals and the applications of poromechanics from the Biot conference of 1998, held in Louvain-la-Neuve. Topics include: wave propogation; numerical modelling; identification of poromechanical parameters; and constitutive modelling.
Download or read book Fundamental Study on Characterization of Porous Media Using Impedance Spectroscopy written by SHIU-WAI. MAK and published by . This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
