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This paper presents a numerical scheme for fluid‐particle coupled discrete element method (DEM), which is based on poro‐elasticity. The motion of the particles is resolved by means of DEM. While within the proposition of Darcian regime, the fluid is assumed as a continuum phase on a Eulerian mesh, and the continuity equation on the fluid mesh for a compressible fluid is solved using the FEM. Analytical solutions of traditional soil mechanics examples, such as the isotropic compression and one‐dimensional upward seepage flow, were used to validate the proposed algorithm quantitatively. The numerical results showed very good agreement with the analytical solutions, which show the correctness of this algorithm. Sensitivity studies on the effect of some influential factors of the coupling scheme such as pore fluid bulk modulus, volumetric strain calculation, and fluid mesh size were performed to display the accuracy, efficiency, and robustness of the numerical algorithm. It is revealed that the pore fluid bulk modulus is a critical parameter that can affect the accuracy of the results. Because of the iterative coupling scheme of these algorithms, high value of fluid bulk modulus can result in instability and consequently reduction in the maximum possible time‐step. Furthermore, the increase of the fluid mesh size reduces the accuracy of the calculated pore pressure. This study enhances our current understanding of the capacity of fluid‐particle coupled DEM to simulate the mechanical behavior of saturated granular materials. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Majid Mathlouthi Fethi Lebdi 《Stochastic Environmental Research and Risk Assessment (SERRA)》2008,22(4):513-528
The paper focuses on the development of reservoir operating rules for dry and rainfall events, and their implementation in
the case of the Ghézala dam located in northern Tunisia (characterized by Mediterranean climate). Rainfall events are defined
in terms of depth and duration that are correlated to each other. A depth analysis per event is performed, conditioned on
the event duration. The gamma distribution provides a good fit to depth per event, especially for events lasting at least
6 days. The event duration fits a geometric distribution, whereas the dry events during the rainy season fit a negative binomial
distribution. The climatic cycle length is fitted to a gamma distribution. On this basis, many 50-year synthetic event series
were generated. Every synthetic streamflow sequence obtained from synthetic rainfall sequences as well as the one derived
from the historic rainfall events time series were optimized and optimal decisions were formulated. These decisions were assessed
by means of multiple regression analysis to estimate the relation between the optimal decision to every stage (dry or rainfall
event) and other system variables. Optimal rules, which have a linear form, were derived by predetermined useful storage interval
and depend on storage, inflows and downstream demand at dry or rainfall event t. The range of t is 1–13 days (rainfall event) and 1–57 days (dry event). The rules were satisfactory for every predetermined useful storage
interval. The simulated dam performance generated by the operation rules was compared with the deterministic optimum operation
and the historical operation. Also included is the comparison of the implicit stochastic optimization-based operation policy
per event during the water years 1985–2002.
相似文献
Fethi LebdiEmail: |
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Abdul Ghaffar Muhammad Akhtar Muhammad Akbar Khan Abdul Majid Khan Khizar Samiullah Mehboob Iqbal 《Journal of the Geological Society of India》2012,80(1):119-122
Partially complete right antler from the Pinjor Formation (Pleistocene) of the Upper Siwalik Subgroup is identified, described and its phylogenetic relationship is discussed. The fossil antler is compared with other known fossil records of family Cervidae as well as with the extant species, on the basis of which it can be attributed to Axis punjabiensis. This species has not been reported previously from this fossil site. 相似文献