The Experts below are selected from a list of 243 Experts worldwide ranked by ideXlab platform
Snehasis Tripathy - One of the best experts on this subject based on the ideXlab platform.
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swelling pressure of a divalent rich bentonite diffuse double Layer Theory revisited
Water Resources Research, 2009Co-Authors: Tom Schanz, Snehasis TripathyAbstract:specimens for a range of dry density of 1.10–1.73 Mg/m 3 were measured experimentally. The clay used was a divalent-rich Ca-Mg-bentonite with 12% exchangeable Na + ions. The theoretical swelling pressure–dry density relationship for the bentonite was determined from the Gouy-Chapman diffuse double-Layer Theory. A comparison of experimental and theoretical results showed that the experimental swelling pressures are either smaller or greater than their theoretical counterparts within different dry density ranges. It is shown that for dry density of the clay less than about 1.55 Mg/m 3 ,a possible dissociation of ions from the surface of the clay platelets contributed to the diffuse double-Layer repulsion. At higher dry densities, the adsorptive forces due to surface and ion hydration dominated the swelling pressures of the clay. A comparison of the modified diffuse double-Layer Theory equations proposed in the literature to determine the swelling pressures of compacted bentonites and the experimental results for the clay in this study showed that the agreement between the calculated and experimental swelling pressure results is very good for dry densities less than 1.55 Mg/m 3 , whereas at higher dry densities the use of the equations was found to be limited.
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Swelling pressure of a divalent‐rich bentonite: Diffuse double‐Layer Theory revisited
Water Resources Research, 2009Co-Authors: Tom Schanz, Snehasis TripathyAbstract:specimens for a range of dry density of 1.10–1.73 Mg/m 3 were measured experimentally. The clay used was a divalent-rich Ca-Mg-bentonite with 12% exchangeable Na + ions. The theoretical swelling pressure–dry density relationship for the bentonite was determined from the Gouy-Chapman diffuse double-Layer Theory. A comparison of experimental and theoretical results showed that the experimental swelling pressures are either smaller or greater than their theoretical counterparts within different dry density ranges. It is shown that for dry density of the clay less than about 1.55 Mg/m 3 ,a possible dissociation of ions from the surface of the clay platelets contributed to the diffuse double-Layer repulsion. At higher dry densities, the adsorptive forces due to surface and ion hydration dominated the swelling pressures of the clay. A comparison of the modified diffuse double-Layer Theory equations proposed in the literature to determine the swelling pressures of compacted bentonites and the experimental results for the clay in this study showed that the agreement between the calculated and experimental swelling pressure results is very good for dry densities less than 1.55 Mg/m 3 , whereas at higher dry densities the use of the equations was found to be limited.
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swelling pressures of compacted bentonites from diffuse double Layer Theory
Canadian Geotechnical Journal, 2004Co-Authors: Snehasis Tripathy, A Sridharan, Tom SchanzAbstract:The swelling pressures of several compacted bentonites (MX80, Febex, and Montigel) proposed for use as barrier materials in storing high-level radioactive waste in many countries were determined from the GouyChapman diffuse double Layer Theory. The swelling pressures thus determined were compared with the reported experimental swelling pressures. The study revealed that, in general, at low compaction dry densities of the bentonites, the experimental swelling pressures are less than their theoretical counterparts, with the reverse trend at high compaction dry densities. Based on the reported experimental results for the three bentonites, relationships between the nondimensional midplane potential function, u, and the nondimensional distance function, Kd, were established. New equations for the swelling pressure were proposed on the basis of the diffuse double Layer Theory and the reported experimental data to compute swelling pressures of compacted bentonites. The suitability of the new equations was also...
Tom Schanz - One of the best experts on this subject based on the ideXlab platform.
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swelling pressure of a divalent rich bentonite diffuse double Layer Theory revisited
Water Resources Research, 2009Co-Authors: Tom Schanz, Snehasis TripathyAbstract:specimens for a range of dry density of 1.10–1.73 Mg/m 3 were measured experimentally. The clay used was a divalent-rich Ca-Mg-bentonite with 12% exchangeable Na + ions. The theoretical swelling pressure–dry density relationship for the bentonite was determined from the Gouy-Chapman diffuse double-Layer Theory. A comparison of experimental and theoretical results showed that the experimental swelling pressures are either smaller or greater than their theoretical counterparts within different dry density ranges. It is shown that for dry density of the clay less than about 1.55 Mg/m 3 ,a possible dissociation of ions from the surface of the clay platelets contributed to the diffuse double-Layer repulsion. At higher dry densities, the adsorptive forces due to surface and ion hydration dominated the swelling pressures of the clay. A comparison of the modified diffuse double-Layer Theory equations proposed in the literature to determine the swelling pressures of compacted bentonites and the experimental results for the clay in this study showed that the agreement between the calculated and experimental swelling pressure results is very good for dry densities less than 1.55 Mg/m 3 , whereas at higher dry densities the use of the equations was found to be limited.
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Swelling pressure of a divalent‐rich bentonite: Diffuse double‐Layer Theory revisited
Water Resources Research, 2009Co-Authors: Tom Schanz, Snehasis TripathyAbstract:specimens for a range of dry density of 1.10–1.73 Mg/m 3 were measured experimentally. The clay used was a divalent-rich Ca-Mg-bentonite with 12% exchangeable Na + ions. The theoretical swelling pressure–dry density relationship for the bentonite was determined from the Gouy-Chapman diffuse double-Layer Theory. A comparison of experimental and theoretical results showed that the experimental swelling pressures are either smaller or greater than their theoretical counterparts within different dry density ranges. It is shown that for dry density of the clay less than about 1.55 Mg/m 3 ,a possible dissociation of ions from the surface of the clay platelets contributed to the diffuse double-Layer repulsion. At higher dry densities, the adsorptive forces due to surface and ion hydration dominated the swelling pressures of the clay. A comparison of the modified diffuse double-Layer Theory equations proposed in the literature to determine the swelling pressures of compacted bentonites and the experimental results for the clay in this study showed that the agreement between the calculated and experimental swelling pressure results is very good for dry densities less than 1.55 Mg/m 3 , whereas at higher dry densities the use of the equations was found to be limited.
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swelling pressures of compacted bentonites from diffuse double Layer Theory
Canadian Geotechnical Journal, 2004Co-Authors: Snehasis Tripathy, A Sridharan, Tom SchanzAbstract:The swelling pressures of several compacted bentonites (MX80, Febex, and Montigel) proposed for use as barrier materials in storing high-level radioactive waste in many countries were determined from the GouyChapman diffuse double Layer Theory. The swelling pressures thus determined were compared with the reported experimental swelling pressures. The study revealed that, in general, at low compaction dry densities of the bentonites, the experimental swelling pressures are less than their theoretical counterparts, with the reverse trend at high compaction dry densities. Based on the reported experimental results for the three bentonites, relationships between the nondimensional midplane potential function, u, and the nondimensional distance function, Kd, were established. New equations for the swelling pressure were proposed on the basis of the diffuse double Layer Theory and the reported experimental data to compute swelling pressures of compacted bentonites. The suitability of the new equations was also...
Stephen J Cowley - One of the best experts on this subject based on the ideXlab platform.
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laminar boundary Layer Theory a 20th century paradox
Annual Review of Fluid Mechanics, 2001Co-Authors: Stephen J CowleyAbstract:Boundary-Layer Theory is crucial in understanding why certain phenomena occur. We start by reviewing steady and unsteady separation from the viewpoint of classical non-interactive boundary-Layer Theory. Next, interactive boundary-Layer Theory is introduced in the context of unsteady separation. This discussion leads onto a consideration of large-Reynolds-number asymptotic instability Theory. We emphasize that a key aspect of boundary-Layer Theory is the development of singularities in solutions of the governing equations. This feature, when combined with the pervasiveness of instabilities, often forces smaller and smaller scales to be considered. Such a cascade of scales can limit the quantitative usefulness of solutions. We also note that classical boundary-Layer Theory may not always be the large-Reynolds-number limit of the Navier-Stokes equations, because of the possible amplification of short-scale modes, which are initially exponentially small, by a Rayleigh instability mechanism.
Klaus Gersten - One of the best experts on this subject based on the ideXlab platform.
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Boundary-Layer Theory
2020Co-Authors: Hermann Schlichting, Klaus GerstenAbstract:This new edition of the near-legendary textbook by Schlichting and revised by Gersten presents a comprehensive overview of boundary-Layer Theory and its application to all areas of fluid mechanics, with particular emphasis on the flow past bodies (e.g. aircraft aerodynamics). The new edition features an updated reference list and over 100 additional changes throughout the book, reflecting the latest advances on the subject
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Extensions to the Prandtl Boundary–Layer Theory
Boundary-Layer Theory, 2016Co-Authors: Hermann Schlichting, Klaus GerstenAbstract:In the previous chapters we have already made mention of higher order boundary–Layer Theory on some different occasions. This Theory treats the effects which were not taken into account in the boundary–Layer equations used up until now. They will now be included in an extension to the Prandtl boundary–Layer Theory to a higher order boundary–Layer Theory. In acquiring this Theory we will simultaneously be able to achieve statements about the region of validity of the Prandtl boundary–Layer Theory.
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Hermann Schlichting and the Boundary-Layer Theory
Notes on Numerical Fluid Mechanics and Multidisciplinary Design, 2009Co-Authors: Klaus GerstenAbstract:After a short summary of the main features of boundary-Layer Theory Hermann Schlichting’s contributions to boundary-Layer Theory are described. They refer to almost all areas of boundary-Layer Theory. Particularly, the following topics are worth mentioning: laminar-turbulent transition, boundary Layers with continuous suction or blowing, boundary Layers in cascade flows of turbomachines, boundary Layers on rough surfaces, laminar airfoils, heat transfer, automobile aerodynamics. A detailed discussion is devoted to Tollmien-Schlichting waves, to the conception of “equivalent roughness” and to the classic and well-known book “Boundary-Layer Theory”, which are and will always be connected with the name of Hermann Schlichting.
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Introduction to Boundary-Layer Theory
Recent Advances in Boundary Layer Theory, 1998Co-Authors: Klaus GerstenAbstract:The basic concepts of Prandtl’s boundary-Layer Theory and the extension to a general asymptotic Theory for flows at high Reynolds numbers are described, and their growing importance is discussed.
Guang Chong Yang - One of the best experts on this subject based on the ideXlab platform.
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On the equationf’’’ +f f’’ + λ(1 -f’2)= 0 with λ ≤ -1/2 arising in boundary Layer Theory
Journal of Applied Mathematics and Computing, 2006Co-Authors: Guang Chong YangAbstract:For any fixed λ ≤ -1/2, there exists f(η) e C1[0,+∞) which satisfies the following nonlinear boundary value problemf’’’ +f f’’ + λ(1 -f’2) = 0a.e.in (0,+∞),f(0)=0,f’(0)=0,f’(+∞) = 1, which arises in boundary Layer Theory in fluid mechanics.
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a note on ƒ ƒƒ λ 1 2 0with λ 0 arising in boundary Layer Theory
Applied Mathematics Letters, 2004Co-Authors: Guang Chong YangAbstract:Abstract For any λ ∈ (−1/2, 0), there exists ƒ (η) e C 1 [0, +∞) such that ƒ‴ + ƒƒ″ + λ(1 − ƒ′ 2 ) = 0, a.e. in (0,+∞), ƒ(0) = 0, ƒ′(0) = 0, ƒ′(+∞) = 1, which arises in boundary Layer Theory in fluid mechanics.
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A note on ƒ‴ + ƒƒ″ + λ(1 − ′2) = 0with λ ∈ (− ½, 0) arising in boundary Layer Theory*
Applied Mathematics Letters, 2004Co-Authors: Guang Chong YangAbstract:Abstract For any λ ∈ (−1/2, 0), there exists ƒ (η) e C 1 [0, +∞) such that ƒ‴ + ƒƒ″ + λ(1 − ƒ′ 2 ) = 0, a.e. in (0,+∞), ƒ(0) = 0, ƒ′(0) = 0, ƒ′(+∞) = 1, which arises in boundary Layer Theory in fluid mechanics.
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existence of solutions to the third order nonlinear differential equations arising in boundary Layer Theory
Applied Mathematics Letters, 2003Co-Authors: Guang Chong YangAbstract:Abstract By a new approach, we prove in this paper that there exists λ 0 ϵ (− 1 2 , 0) such that the following third-order nonlinear boundary value problem for f(η): f‴+ff″+λ(1−f′2)=0, 0 , f(0)=0, f′(0)=0, f′(+∞)=1, which arises in boundary Layer Theory in fluid mechanics, has a solution at least for any fixed λ ϵ (λ0, 0).