The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
N H S Oliver - One of the best experts on this subject based on the ideXlab platform.
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mechanical controls on Fluid Flow during regional metamorphism some numerical models
Journal of Metamorphic Geology, 1997Co-Authors: Alison Ord, N H S OliverAbstract:The control of Fluid Flow by plastic deformation during metamorphism is critical to our understanding of metamorphic processes. Various geological observations and field studies demonstrate the consequences of Fluid Flow control by deformation, so that the concept appears to be accepted, at least for small-scale PUBLIC (for example faults and vein PUBLIC). However, the concept appears to be less well recognized at regional scales. Considered here are examples of simple, conceptual models based on fully coupled mechanical–Fluid Flow concepts; they include deformation of a section of Fluid-saturated crust containing a block or a layer of material of different properties from its surrounds. In particular, rheological and permeability contrasts between rock types during deformation associated with regional metamorphism are sufficient to control the form of Fluid Flow over the range of a few kilometres. Low contrasts and small strains allow pervasive Fluid Flow, whereas greater contrasts and increasing strains cause focusing of the Flow. Such focusing is generally associated with localization of the deformation, especially for a strongly dilatant elastic–plastic material. However, a rate of Fluid Flow much greater than the rate of deformation may result in pervasive Flow, although for most models pervasive Flow is difficult to attain over regional distances. Furthermore, lateral and downward Fluid Flow may occur, demonstrated here by simple models for folding and for deformation of regions containing plutons. Therefore, such modelling may be used as a means of testing the various hypotheses concerning the volumes of Fluid predicted to have passed through some rock volumes. Numerical models of the future will become increasingly complex and powerful, allowing greater coupling of thermal, mechanical, chemical and Fluid Flow effects, and based more on the physical processes involved. Combined field and laboratory studies will provide correspondingly greater understanding and will permit the determination of the timing of Fluid Flow and structural controls on Fluid Flow patterns.
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review and classification of structural controls on Fluid Flow during regional metamorphism
Journal of Metamorphic Geology, 1996Co-Authors: N H S OliverAbstract:Mechanisms for kilometre-scale, open-system Fluid Flow during regional metamorphism remain problematic. Debate also continues over the degree of Fluid Flow channellization during regional metamorphism, and the mechanisms for pervasive Fluid Flow at depth. The requirements for pervasive long-distance Fluid Flow are an interconnected porosity and a large regional gradient in Fluid pressure and hydraulic head (thermally or structurally controlled) that dominates over local perturbations in hydraulic head due to deformation. In contrast, dynamic or transient porosity interconnection and Fluid Flow accompanying deformation of heterogeneous rock suites should result in moderately to strongly channellized Flow at a range of scales, of which there are many examples in the literature. Classification of Fluid Flow types based on scale and degree of equilibration between Fluid and rock, wallrock permeability, and mode of Fluid transport contributes to an understanding of key factors that control Fluid Flow. Closed-system Fluid behaviour, with restricted Fluid Flow in microcracks or cracks and limited Fluid–rock interaction, occurs over a range of strains and crustal depths, but requires low permeabilities and/or small Fluid fluxes. Long-distance, open-system Fluid Flow in channels is favoured in heterogeneous rocks at high strains, moderate (but variable) permeabilities, and moderate to high Fluid fluxes. Long-distance, broad, pervasive Fluid Flow during regional metamorphism requires that the rocks are not accumulating high strains and have high permeabilities, low permeability contrasts, and high Fluid fluxes. The ideal situation for such Fluid Flow is in situations where the rocks are undergoing stress relaxation immediately after a major deformation phase. In the mid-crust, fairly specific conditions are thus required for pervasive Fluid Flow. During active orogenesis, structurally controlled Fluid Flow (with focused open systems surrounding regions of closed-system behaviour) predominates in most, but not all, regional metamorphic situations, at a range of scales.
Per Aspenberg - One of the best experts on this subject based on the ideXlab platform.
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Bone Resorption Induced by Fluid Flow
Journal of biomechanical engineering, 2009Co-Authors: Lars Johansson, Ulf Edlund, Anna Fahlgren, Per AspenbergAbstract:A model where bone resorption is driven by stimulus from Fluid Flow is developed and used as a basis for computer simulations, which are compared with experiments. Models for bone remodeling are usually based on the state of stress, strain, or energy density of the bone tissue as the stimulus for remodeling. We believe that there is experimental support for an additional pathway, where an increase in the amount of osteoclasts, and thus osteolysis, is caused by the time history of Fluid Flow velocity, Fluid pressure, or other parameters related to Fluid Flow at the bone/soft tissue interface of the porosities in the bone.
Abdorreza Asrar - One of the best experts on this subject based on the ideXlab platform.
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A passive mechanical system for moving against Fluid Flow
Extreme Mechanics Letters, 2018Co-Authors: Abdorreza AsrarAbstract:Abstract Always the extraordinary phenomena are interesting for everybody. Sometimes a simple idea can leads to amazing results. Here, we will consider the special case of the interaction of the Fluid Flow and a propeller. Usually, the interaction of the Fluid Flow and a propeller divided into the two categories. In the first category the rotation of a propeller generates a Flow in the Fluid and in the second category, the Fluid Flow rotates a propeller. The first is energy consuming and the second one is energy generating. In some special conditions we can make a closed loop for generating and consuming the energy. In this paper I will offer a simple mechanical sketch for a device to move against the Fluid Flow direction without any external energy source. In fact by using some simple rules and principles of Newtonian mechanics, the suggested device can move against Fluid Flow direction using the energy of Fluid itself. Such devices are important because of their capability for access to points, out of other types of energy, for example the end of deep and high Flow rate wells such as oil and gas wells; or for design of any device to go forward and backward with same Flow directions.
David Lumley - One of the best experts on this subject based on the ideXlab platform.
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Seismic monitoring of hydrocarbon Fluid Flow
Journal of Mathematical Imaging and Vision, 1995Co-Authors: David LumleyAbstract:Time-lapse 3-D seismic monitoring of subsurface rock property changes incurred during reservoir Fluid-Flow processes is an emerging new diagnostic technology for optimizing hydrocarbon production. I discuss the physical theory relevant for three-phase Fluid Flow in a producing oil reservoir, and rock physics transformations of Fluid-Flow pressure, temperature and pore-Fluid saturation values to seismic P-wave and S-wave velocity. I link Fluid-Flow physical parameters to seismic reflection data amplitudes and traveltimes through elastic wave equation modeling and imaging theory. I demonstrate in a simulated data example that changes in Fluid-Flow can be monitored and imaged from repeated seismic surveys acquired at varying production calendar times.
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Four-dimensional seismic monitoring of reservoir Fluid-Flow processes
Mathematical Methods in Geophysical Imaging II, 1994Co-Authors: David LumleyAbstract:Time-lapse 3D seismic monitoring of subsurface rock property changes incurred during reservoir Fluid-Flow processes is an emerging new diagnostic technology for optimizing hydrocarbon production. I discuss the physical theory relevant for three-phase Fluid Flow in a producing oil reservoir, and rock physics transformations of Fluid-Flow pressure, temperature and pore-Fluid saturation values to seismic P-wave and S-wave velocity. I link Fluid-Flow physical parameters to seismic reflection data amplitudes and traveltimes through elastic wave equation modeling and imaging theory. I demonstrate in a simulated data example that changes in Fluid-Flow can be monitored and imaged from repeated seismic surveys acquired at varying production calendar times.
B. N. J. Persson - One of the best experts on this subject based on the ideXlab platform.
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Interfacial Fluid Flow for systems with anisotropic roughness.
The European physical journal. E Soft matter, 2020Co-Authors: B. N. J. PerssonAbstract:I discuss Fluid Flow at the interface between solids with anisotropic roughness. I show that the Bruggeman effective medium theory and the critical junction theory give nearly the same results for the Fluid Flow conductivity. This shows that, in most cases, the surface roughness observed at high magnification is irrelevant for Fluid Flow problems such as the leakage of static seals, and Fluid squeeze-out. The effective medium theory predicts that the Fluid Flow conductivity vanishes at the relative contact area A/A0 = 0.5 independent of the anisotropy. However, the effective medium theory does not solve the elastic contact mechanics problem but is based on a purely geometric argument. Thus, for anisotropic roughness the contact area may percolate at different values of A/A0 depending on the direction. We discuss how this may be taken into account in the effective medium and critical junction theories.
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Interfacial Fluid Flow for systems with anisotropic roughness
arXiv: Soft Condensed Matter, 2020Co-Authors: B. N. J. PerssonAbstract:I discuss Fluid Flow at the interface between solids with anisotropic roughness. I show that for randomly rough surfaces with anisotropic roughness, the contact area percolate at the same relative contact area as for isotropic roughness, and that the Bruggeman effective medium theory and the critical junction theory give nearly the same results for the Fluid Flow conductivity. This shows that, in most cases, the surface roughness observed at high magnification is irrelevant for Fluid Flow problems such as the leakage of static seals, and Fluid squeeze-out.
