117 research outputs found
Regional Flow Simulation in Fractured Aquifers Using Stress-Dependent Parameters
A model function relating effective stress to fracture permeability is
developed from Hooke's law, implemented in the tensorial form of Darcy's law,
and used to evaluate discharge rates and pressure distributions at regional
scales. The model takes into account elastic and statistical fracture
parameters, and is able to simulate real stress-dependent permeabilities from
laboratory to field studies. This modeling approach gains in phenomenology in
comparison to the classical ones because the permeability tensors may vary in
both strength and principal directions according to effective stresses.
Moreover this method allows evaluation of the fracture porosity changes, which
are then translated into consolidation of the medium.Comment: 10 pages, 7 figures, submitted to Ground Water 201
Wave attenuation and dissipation mechanisms in viscoelastic phononic crystals
This work investigates wave attenuation and dissipation mechanisms in viscoelastic phononic crystals (VPCs) having different inclusion types in a long-wavelength regime. After investigating the intrinsic damping properties of VPCs for different inclusion sizes and materials, we carried out wave simulations revealing the energy dissipation by a finite VPC structure inserted inside an elastic medium. The simulations, supported by physical reasoning, showed that air-and metal-embedded VPCs can indeed dissipate more wave energy than pure viscoelastic media in low and high frequency ranges, respectively. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4795285clos
Thermal design and characterization of a modular integrated liquid cooled 1200 V-35 A SiC MOSFET bi-directional switch
The aim of this work is the thermal design of a modular direct liquid cooled package for 1200 V–35 A SiC power MOSFETs, in order to take full advantage of the high power density and high frequency performance of these devices, in the development of a modular integrated solution for power converters. An accurate electro-thermal fluid dynamic model is set up and validated by thermal characterization on a prototype; numerical models have been used to study the internal temperature distribution and to propose further optimization
Inverted bi-prism phononic crystals for one-sided elastic wave transmission applications
This work presents the realization of one-sided wave transmission by using a specially engineered phononic crystal structure. It is an inverted bi-prism phononic crystal engineered for a horizontally incident elastic wave at a specific frequency. The incident wave along one direction is shown to be totally reflected by the bi-prism while the incident wave along the opposite direction transmitted through it with refraction, also evident from experiments. An application of the proposed bi-prism may be found in thin elastic strips. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4721485clos
A thermopile detector array with scaled TE elements for use in an integrated IR microspectrometer
Regional Flow and Deformation Analysis of Basin-Fill Aquifer Systems Using Stress-Dependent Parameters
A comprehensive mathematical model of heat and moisture transfer for wood convective drying
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