Computational Methods In Water Resources Research Articles

Robust shallow water models

Shallow water models have been used extensively for decades with various applications in hydroscience and engineering such as flood prediction and management, river restoration and engineering, environmental hydraulics and morphodynamics. In recent years, there has been a special focus on developing robust solvers which are capable of simulating a wide range of complex hydrodynamic problems including dam breaks (shock propagation, wetting and drying, small water depths), as well as flow transitions (subcritical–supercritical flow and vice versa, hydraulic jumps). In addition to classical finite-volume and finite-element schemes, newer methods such as smoothed particle hydrodynamics (SPH) are now being applied and extended. Furthermore, we have seen rapid development in surveying techniques (e.g. airborne and terrestrial laser scanning) which describe the geometry and physical properties of our systems, providing us with increasingly high-resolution information. Substantial improvements have also been made in high-performance computing, with notable advances including Graphic Processing Unit (GPU)-based parallel computing as well as scaling methods, relying, for example, on frictionor porosity-based approaches. Linkage of robust numerical methods, highresolution data, high-performance computing, scaling methods and new information and communication technologies will lead to the next generation of shallow water models opening up new application fields such as rainfall– runoff simulation in urban and rural catchments, real-time flood and tsunami prediction and management, as well as the spreading of impulse water waves generated by landslides. In view of these developments, we have encouraged submissions on both the development of numerical models and interesting applications, for the XX International Conference on Computational Methods in Water Resources held on June 10–13, 2014 in Stuttgart, Germany, especially for the sessions on ‘Robust shallow water models’, ‘Numerical methods for waves, circulation and transport in the coastal Ocean’ and ‘High-performance computing, visualization and scientific workflow’. This special issue contains papers which have been selected by the guest editors among about 20 contributions. The corresponding authors have been offered the opportunity to contribute to this special issue through a paper about their conference contribution (abstract, oral, or poster presentation). The papers have all undergone a full peer-review process as regular journal submissions and, finally, we are happy to present this special issue consisting of ten papers. This special issue widens the already existing journal focus on shallow water models and their applications, see, for example, Delfs et al. (2013), Shi et al. (2014), Carbajal et al. (2014) or Huang et al. (2014). This special issue starts with two contributions dealing with floods. Beisiegel and Behrens (2015) have developed a robust discontinuous Galerkin (DG) model using special basis functions and a slope limiter. Flooding and drying is simulated through applying a stable scheme, and the model’s advantages are demonstrated in a numerical study. & Reinhard Hinkelmann reinhard.hinkelmann@wahyd.tu-berlin.de

Investigation of flows in solidification by using the lattice Boltzmann method

The lattice Boltzmann method (LBM) is adopted to solve melting and solidification problems. D2Q9 lattice is used to solve 2D fluid flow and heat transfer problem by using two distribution functions approach. The phase interface is traced by using partial or probabilistic bounce back approach suggested by Thorne and Sukop [D.T. Thorne, M. Sukop, Lattice Boltzmann method for the Elder problem, in: C.T. Miller, M.W. Farthing, W.G. Gray, G.F. Pinder (Eds.), Proceedings of Int. Conf. Computational Methods in Water Resources (CMWR XV), June 13–17, 2004, Chapel Hill, NC, USA, Elsevier, Amsterdam] for simulation of flow in porous medium. The considered scheme is first validated for natural convection without and with phase change coupling and results were well compared with benchmark and with published experimental results. Also, the predicted solutions for phase change problems were compared with the predictions of conventional method. The results are interesting and demonstrate that approach can produce dependable results.

Computational Methods in Water Resources: Proceedings of the XIVth International Conference on Computational Methods in Water Resources, 23-28 June 2002, Delft, The Netherlands.

S.M. HASSANIZADEH, R.J. SCHOTTING, W.G. GRAY, and G.F. PINDER (ed.) Elsevier Science, Amsterdam. 2002. Volumes 1 and 2. Hardback, 1808 pp. $355.00. ISBN 0-444-50975-5. Following rapid advances during the last two decades, computer simulation has now become an irreplaceable part of our efforts to

Computational Methods in Water Resources. Proceedings of the XIVth International Conference on Computational Methods in Water Resources, 23–28 June 2002, Delft, The Netherlands

Computational Methods in Water Resources. Proceedings of the XIVth International Conference on Computational Methods in Water Resources, 23–28 June 2002, Delft, The Netherlands

Superconvergence and Postprocessing of Fluxes from Lowest-Order Mixed Methods on Triangles and Tetrahedra

Certain finite difference methods on rectangular grids for second-order elliptic equations are known to yield superconvergent flux approximations. A class of related finite difference methods recently have been defined for triangular meshes by applying special quadrature rules to an extended version of a mixed finite element method by Arbogast, Dawson, and Keenan [Mixed Finite Element Methods as Finite Difference Methods for Solving Elliptic Equations on Triangular Elements, Tech. report 93-53, Dept. of Computational and Applied Mathematics, Rice University, Houston, TX, 1993; in Computational Methods in Water Resources, Kluwer Academic Publishers, Norwell, MA, 1994]; the usual hybrid mixed method can also be applied to meshes of triangular and tetrahedral elements. Unfortunately, the flux vectors from these methods are only first-order accurate. Empirical evidence indicates that a local postprocessing technique described by Keenan in [An Efficient Postprocessor for Velocities from Mixed Methods on Triangular Elements, Dept. of Computational and Applied Mathematics, Tech. report 94-22, Rice University, Houston, TX, 1994] recovers second-order accurate velocities at special points. In this paper, a class of local postprocessing techniques generalizing the one in [An Efficient Postprocessor for Velocities from Mixed Methods on Triangular Elements, Tech. report 94-22, Rice University, Houston, TX, 1994] are presented and analyzed. These postprocessors are shown to recover second-order accurate velocity fields on three lines meshes. Numerical experiments illustrate these results and investigate more general situations, including meshes of tetrahedral elements.

International Conference on COMPUTATIONAL METHODS IN WATER RESOURCES

International Conference on COMPUTATIONAL METHODS IN WATER RESOURCES

2nd Tidal Flow Forum

On June 14, 1988, the 2nd Tidal Flow Forum was held at the VIIth International Conference on Computational Methods in Water Resources. The meeting took place in Boston, at the Massachusetts Institute of Technology, with the participation of scientists and engineers from North America and Europe. Simulations of the tides in the English Channel and the southern bight of the North Sea (see figure) with two‐dimensional state‐of‐the‐art finite element and finite difference models were presented. By seeking to establish a benchmark computation, the conclusions reached at the Forum represent an important contribution to the understanding of our present‐day numerical modeling capabilities in the area of tidal hydrodynamics.

Seventh international conference on computational methods in water resources: (Formerly finite element in water resources) Massachusetts Institute of Technology, Cambridge, MA, 13–17 June, 1988

Seventh international conference on computational methods in water resources: (Formerly finite element in water resources) Massachusetts Institute of Technology, Cambridge, MA, 13–17 June, 1988