1,721,038 research outputs found
A comparison between different simulators for non-isothermal consolidation
No full textStuttgart, German
Numerical optimisation of tilt casting process
No full textA coupled mould filling and solidification algorithm based on the Finite Element Method is presented for the tilt casting process. The incompressible, Navier-Stokes equations are solved by the Galerkin finite element method; the metal front is tracked by the pseudo-concentration approach, which is a variant of the volume of fluid method (VOF) and the latent heat release during solidification is taken into account through an effective specific heat. A coincidence-node technique is used to simulate the discontinuity in the temperature field across the metal/mould interface. The tilt casting phenomenon is numerically modelled by keeping the mould stationary and rotating the gravitational force vector. A mathematical expression relating tilting angle to the tilting speed has been proposed so that an optimal value of tilting speed can be predicted by minimising splashing effects. The free surface tracking algorithm is validated against the widely used broken dam problem. The tilt casting results are compared with the experimental results that were available in the literature
A finite element analysis of multiphase immiscible flow in deforming porous media for subsurface systems
No full textA fully coupled numerical model has been developed which describes multiphase fluid flow through soil: namely gas, water and a non-aqueous phase liquid (NAPL) in a deforming porous media for subsurface systems. A multiphase flow model, based on the two-phase flow model of Brooks and Corey, is presented to express the dependence of saturation and relative permeability on the capillary pressure. Non-linear saturation and relative permeability functions are incorporated into a Galerkin finite element model which is subsequently used to simulate multiphase immiscible fluid flow under saturated and unsaturated conditions in porous media. The governing partial differential equations, in terms of soil displacements and fluid pressures, which are coupled and non-linear, are solved by the finite element method. Numerical imple-mentation of the formulation is discussed, and example problems demonstrate the model and solution procedure
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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