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Bernard Leroy 《地球物理与天体物理流体动力学》2013,107(2):123-133
Abstract New light is shed on the derivation of the energy flux of the linear MHD waves. It is shown that, according to a suggestion of Lighthill, the usual perturbation procedure, which starts from the general expression for the energy flux, need not be supplemented by an averaging procedure. As a result, it is shown that to second order in the wave amplitude, a quantity identifiable as the wave energy flux is conserved. Some of the subtleties inherent in the derivation of the pertubation energy equation are discussed. 相似文献
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The equations for a compositional model for simulation of a two-phase, three-component system with inter-phase mass transfer are developed. Emphasis is placed on development of inter-phase mass transfer equations for incorporation of rate-limited inter-phase mass transfer. Due to the nature of the three-component systems considered, a single-film model may be inadequate and a two-film model must be utilized. A two-film model accounts for the simultaneous transfer of components in both directions across phase interfaces. The effect of interaction between components on diffusion is considered using a general form of Fick's Law. A Hand Plot representation of ternary phase behavior is chosen since it allows for straightforward calculation of miscibility of bulk phases under conditions of local non-equilibrium. The developed set of equations form the basis for a numerical model to simulate the enhanced removal of non-aqueous phase liquids (NAPLs) from porous media using single-component alcohol floods. 相似文献
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Agnès Mazot Alain Bernard Tobias Fischer Salvatore Inguaggiato Igan S. Sutawidjaja 《Journal of Volcanology and Geothermal Research》2008
Papandayan is a stratovolcano situated in West Java, Indonesia. Since the last magmatic eruption in 1772, only few hydrothermal explosions have occurred. An explosive eruption occurred in November 2002 and ejected ash and altered rocks. The altered rocks show that an advanced argillic alteration took place in the hydrothermal system by interaction between acid fluids and rocks. Four zones of alteration have been defined and are limited in extension and shape along faults or across permeable structures at different levels beneath the active crater of the volcano. 相似文献
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Space- and ground-based measurements of sulphur dioxide emissions from Turrialba Volcano (Costa Rica) 总被引:2,自引:0,他引:2
Robin Campion Maria Martinez-Cruz Thomas Lecocq Corentin Caudron Javier Pacheco Gaia Pinardi Christian Hermans Simon Carn Alain Bernard 《Bulletin of Volcanology》2012,74(7):1757-1770
Remotely sensed measurements of sulphur dioxide (SO2) emitted by Turrialba Volcano (Costa Rica) are reported for the period September 2009–January 2011. These measurements were obtained using images from Advanced Spaceborne Thermal Emission and Reflexion radiometer, Ozone Monitoring Instrument and a ground-based UV camera. These three very different instruments provide flux measurements in good agreement with each other, which demonstrate that they can be integrated for monitoring SO2 fluxes. Fluxes from Turrialba increased fourfold in January 2010, following a phreatic explosion that formed a degassing vent in the W crater of Turrialba. Since then, the SO2 flux has remained high (30–50?kg/s) but seems to be showing a slowly decreasing trend. We interpret this evolution as the start of open vent degassing from a recently intruded magma body. The opening of the degassing vent decreased the confining pressure of the magma body and allowed the gases to bypass the hydrothermal system. 相似文献
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This paper aims to assess MODFLOW and MT3D capabilities for simulating the spread of contaminants from a river exhibiting an unusual relationship with an alluvial aquifer, with the groundwater head higher than the river head on one side and lower on the other (flow‐through stream). A series of simulation tests is conducted using a simple hypothetical model so as to characterize and quantify these limitations. Simulation results show that the expected contaminant spread could be achieved with a specific configuration composed of two sets of parameters: (1) modeled object parameters (hydraulic groundwater gradient, hydraulic conductivity values of aquifer and streambed), and (2) modeling parameters (vertical discretization of aquifer, horizontal refinement of stream modeled with River [RIV] package). The influence of these various parameters on simulation results is investigated, and potential complications and errors are identified. Contaminant spread from stream to aquifer is not always reproduced by MT3D due to the RIV package's inability to simulate lateral exchange fluxes between stream and aquifer. This paper identifies the need for a MODFLOW streamflow package allowing lateral stream‐aquifer interactions and streamflow routine calculations. Such developments could be of particular interest for modeling contaminated flow‐through streams. 相似文献