25 research outputs found
Transient MHD Double-Diffusive Natural Convection over a Vertical Surface Embedded in a Non-Darcy Porous Medium
The problem of transient, laminar, MHD double-diffusive free convection over a permeable vertical plate embedded in Darcy and non-Darcy porous medium is numerically investigated. Nonsimilarity solutions are obtained for constant wall temperature and concentration with a specified power law of mass flux parameter. The effects of the magnetic parameter, the inertial coefficient, Lewis number, the buoyancy ratio, and the lateral mass flux on heat and mass transfer coefficients are presented and discussed
New perspectives on interdisciplinary earth science at the Dead Sea: The DESERVE project
The Dead Sea region has faced substantial environmental challenges in recent decades, including water resource scarcity, ~ 1 m annual decreases in the water level, sinkhole development, ascending-brine freshwater pollution, and seismic disturbance risks. Natural processes are significantly affected by human interference as well as by climate change and tectonic developments over the long term. To get a deep understanding of processes and their interactions, innovative scientific approaches that integrate disciplinary research and education are required. The research project DESERVE (Helmholtz Virtual Institute Dead Sea Research Venue) addresses these challenges in an interdisciplinary approach that includes geophysics, hydrology, and meteorology. The project is implemented by a consortium of scientific institutions in neighboring countries of the Dead Sea (Israel, Jordan, Palestine Territories) and participating German Helmholtz Centres (KIT, GFZ, UFZ). A new monitoring network of meteorological, hydrological, and seismic/geodynamic stations has been established, and extensive field research and numerical simulations have been undertaken. For the first time, innovative measurement and modeling techniques have been applied to the extreme conditions of the Dead Sea and its surroundings. The preliminary results show the potential of these methods. First time ever performed eddy covariance measurements give insight into the governing factors of Dead Sea evaporation. High-resolution bathymetric investigations reveal a strong correlation between submarine springs and neo-tectonic patterns. Based on detailed studies of stratigraphy and borehole information, the extension of the subsurface drainage basin of the Dead Sea is now reliably estimated. Originality has been achieved in monitoring flash floods in an arid basin at its outlet and simultaneously in tributaries, supplemented by spatio-temporal rainfall data. Low-altitude, high resolution photogrammetry, allied to satellite image analysis and to geophysical surveys (e.g. shear-wave reflections) has enabled a more detailed characterization of sinkhole morphology and temporal development and the possible subsurface controls thereon. All the above listed efforts and scientific results take place with the interdisciplinary education of young scientists. They are invited to attend joint thematic workshops and winter schools as well as to participate in field experiments
Experimentelle Untersuchung der Kontraktion in scharfkantigen, kurzen Blenden bei Einphasenund Zweiphasenströmung
Two-Phase Slug Flow Pressure Drop in a Tee-Junction
An experimental test loop system was designed, developed, and constructed to study the two-phase flow field. Horizontally oriented inlet and branches piping system, with sharp edge T-junction, at a system pressure of 1 bar was investigated. Measurements of air and water mass flow rates and temperatures in slug flow regime with variable inlet mass fluxes, extraction rates, and qualities are presented. Single-phase loss coefficients were determined, correlated and compared with different proposed correlations. The statistical mean predictive accuracy of the measured pressure difference values are compared with the separated flow model and Riemann and Seeger model in the way of parity plot. Riemann and Seeger model showed better predictions with the present data. It is also concluded that the pressure difference depends on the inlet mass fluxes, inlet qualities and extraction rates, and there is a strong interdependence between the separation phenomena and the pressure distribution