BibTeX-friendly

The publication list delivered as friendly as possible for the LaTeX users, in the form of the familiar BibTeX data base, just copy-and-paste. Concerns only journal and conference papers. The formal links lead to contents elsewhere, this means: by the publishers. Thanks to papercite plugin.

2018

  • Platzek, F. W., Stelling, G. S., Jankowski, J. A., Patzwahl, R., & Pietrzak, J. D.. (2018). River computations: artificial backwater from the momentum advection scheme. Journal of Hydraulic Research, 1-16. doi:10.1080/00221686.2017.1399935
    [BibTeX] [Abstract] [Download PDF]

    The established method for determining dike heights and dimensioning river training structures is to assess the resulting backwater by numerical modelling. The common consensus is that bottom friction determines the backwater and that momentum advection only has a local effect. We demonstrate that the numerical/artificial backwater contribution from the momentum advection approximation can be of the same order of magnitude as the bottom friction contribution, depending on the advection scheme. This is realized using a one-dimensional analysis and verified using a set of one- and two-dimensional test problems including a wavy bed case, flow over emerged and submerged groynes and finally an actual river. We compare first- and second-order accurate advection schemes and compute their artificial contribution to the backwater, for a range of practically-feasible grid resolutions. The tests demonstrate that the conservation/constancy properties of the scheme determine the size of this contribution, rather than the order of the scheme.

    @ARTICLE{Platzek2018,
    author = {Frank W. Platzek and Guus S. Stelling and Jacek A. Jankowski and
    Regina Patzwahl and Julie D. Pietrzak},
    title = {River computations: artificial backwater from the momentum advection
    scheme},
    journal = {Journal of Hydraulic Research},
    year = {2018},
    volume = {0},
    pages = {1-16},
    number = {0},
    note = {Published online: 05 Mar 2018},
    abstract = {The established method for determining dike heights and dimensioning
    river training structures is to assess the resulting backwater by
    numerical modelling. The common consensus is that bottom friction
    determines the backwater and that momentum advection only has a local
    effect. We demonstrate that the numerical/artificial backwater contribution
    from the momentum advection approximation can be of the same order
    of magnitude as the bottom friction contribution, depending on the
    advection scheme. This is realized using a one-dimensional analysis
    and verified using a set of one- and two-dimensional test problems
    including a wavy bed case, flow over emerged and submerged groynes
    and finally an actual river. We compare first- and second-order accurate
    advection schemes and compute their artificial contribution to the
    backwater, for a range of practically-feasible grid resolutions.
    The tests demonstrate that the conservation/constancy properties
    of the scheme determine the size of this contribution, rather than
    the order of the scheme.},
    doi = {10.1080/00221686.2017.1399935},
    eprint = { https://doi.org/10.1080/00221686.2017.1399935 },
    owner = {jaj},
    publisher = {Taylor \& Francis},
    timestamp = {2018.03.10},
    url = { https://doi.org/10.1080/00221686.2017.1399935 }
    }

2016

  • Platzek, F. W., Stelling, G. S., Jankowski, J. A., Patzwahl, R., & Pietrzak, J. D.. (2016). An efficient semi-implicit subgrid method for free-surface flows on hierarchical grids. International Journal for Numerical Methods in Fluids, 80(12), 715–741. doi:10.1002/fld.4172
    [BibTeX] [Abstract] [Download PDF]

    We present a new modelling strategy for improving the efficiency of computationally intensive flow problems in environmental free-surface flows. The approach combines a recently developed semi-implicit subgrid method with a hierarchical grid solution strategy. The method allows the incorporation of high-resolution data on subgrid scale to obtain a more accurate and efficient hydrodynamic model. The subgrid method improves the efficiency of the hierarchical grid method by providing better solutions on coarse grids. The method is applicable to both steady and unsteady flows, but we particularly focus on river flows with steady boundary conditions. There, the combined hierarchical grid–subgrid method reduces the computational effort to obtain a steady state with factors up to 43. For unsteady models, the method can be used for efficiently generating accurate initial conditions on high-resolution grids. Additionally, the method provides automatic insight in grid convergence. We demonstrate the efficiency and applicability of the method using a schematic test for the vortex shedding around a circular cylinder and a real-world river case study.

    @ARTICLE{Platzek2015,
    author = {Platzek, F. W. and Stelling, G. S. and Jankowski, J. A. and Patzwahl,
    R. and Pietrzak, J. D.},
    title = {An efficient semi-implicit subgrid method for free-surface flows
    on hierarchical grids},
    journal = {International Journal for Numerical Methods in Fluids},
    year = {2016},
    volume = {80},
    pages = {715--741},
    number = {12},
    note = {fld.4172},
    abstract = {We present a new modelling strategy for improving the efficiency of
    computationally intensive flow problems in environmental free-surface
    flows. The approach combines a recently developed semi-implicit subgrid
    method with a hierarchical grid solution strategy. The method allows
    the incorporation of high-resolution data on subgrid scale to obtain
    a more accurate and efficient hydrodynamic model. The subgrid method
    improves the efficiency of the hierarchical grid method by providing
    better solutions on coarse grids. The method is applicable to both
    steady and unsteady flows, but we particularly focus on river flows
    with steady boundary conditions. There, the combined hierarchical
    grid–subgrid method reduces the computational effort to obtain a
    steady state with factors up to 43. For unsteady models, the method
    can be used for efficiently generating accurate initial conditions
    on high-resolution grids. Additionally, the method provides automatic
    insight in grid convergence. We demonstrate the efficiency and applicability
    of the method using a schematic test for the vortex shedding around
    a circular cylinder and a real-world river case study.},
    doi = {10.1002/fld.4172},
    issn = {1097-0363},
    keywords = {subgrid method, hierarchical grids, grid convergence, efficiency,
    steady-state computations, shallow water},
    owner = {jaj},
    timestamp = {2015.09.07},
    url = {http://dx.doi.org/10.1002/fld.4172}
    }

  • Rustico, E., & Jankowski, J. A.. (2016). Evaluation and adaption of the SPH method for hydraulic engineering problems on federal waterways (final report). B3953.05.04.70002: Bundesanstalt für Wasserbau (BAW).
    [BibTeX] [Abstract] [Download PDF]

    Smoothed Particle Hydrodynamics (SPH) is a Lagrangian method for fluid dynamic simulations. In the past decades it drew the attention of the scientific community for its versatility and the possibility to simulate complex phenomena such as e.g. surface tension and fluid-solid interactions with floating objects. SPH has in general higher computational requirements than the most common Eulerian methods and several different models have been proposed for the treatment of boundaries, each with advantages and limitations. The project aimed to develop, validate and increase the computational efficiency of an existing SPH code for hydraulic engineering problems. As base code for the development, the GPUSPH simulator has been chosen. As the name suggests, it is a SPH implementation which exploits the Graphic Processing Units (GPU) to perform the computation of the particle to particle interactions. The GPUSPH simulator has been developed within the ATHOS Consortium, whose members include universities and research institutes from different nations working on different aspects of the code. A development branch external to BAW butof particular interest for the project regards the newer “Semi-Analytical” boundary model, the development of which has been completed only recently. In the first phase, several features have been improved or introduced in the simulator, especially the capability of splitting a simulation across multiple nodes of a cluster each equipped with one or more GPU devices. This additional level of parallelism has enabled the simulation of high-resolution or spatially big scenarios (more than 100 million particles). In the second phase, two test cases have been developed. The first is a fish pass, that has been modeled following the plan of a physical scaled model situated in the laboratories of BAW Karlsruhe. Simple Lennard-Jones boundaries have been used, featuring “pseudo-open” boundaries capable of controlling the inlet flow and specifically developed for the test case. A comparison of the simulated flow and a set of laboratory measurements highlighted a very good agreement in terms of the stream shape, including the recirculation areas. The water level were however too high in the simulated model because of an excess of friction due to the boundary model. A ship lock has been modeled as second test case replicating the new Kiel-Holtenau lock, of which a scaled model was built at BAW Karlsruhe. The first implementation used the Semi-Analytical boundaries, featuring pressure- or velocity-driver open boundaries. Although the first results appeared to be promising, the low computational performance of the boundary model made a continuation of the tests on a large scale infeasible. Since a performance-optimized version of the model was not yet available (and is still in progress within the consortium), a second attempt has been done with the Dynamic Boundaries, a lighter boundary model featuring correct pressure at the boundaries but no inlets. The water inflow has been implemented either with “pseudo-inlet” and with a piston chamber. Both attempts showed a strong artifact causing the stream flow to go upward and hit the ship frontally rather than passing under it. This yielded the forces acting on the ship to be stronger than the forces measured in a laboratory model at BAW. The causes of the difference have been identified with high probability in the artificial stream lift caused by the non-physical inlet and the excess of friction along the ship hull. Both factors could be eliminated with a more physics-adherent boundary model. The test cases highlighted the limits of the simpler boundary models and the need for an optimized, industrial-level version of the newly developed Semi-Analytical boundaries. Although the current development status and the first results are very promising for the applicability of the method to complex real-life engineering problems, and are already being used in the scientific community for many simpler problem scenarios, an optimization of the new boundary model is crucial to free the high potential of the method and accurately determine its application range and characteristics. An additional time of at least one year would be required to re-implement both test cases with the new model and produce a definitive comparison, granted the availability of the consortium members involving the optimization of the boundary model.

    @TECHREPORT{Rustico2016final,
    author = {Rustico, E. and Jankowski, J.A.},
    title = {Evaluation and adaption of the SPH method for hydraulic engineering
    problems on federal waterways},
    institution = {Bundesanstalt für Wasserbau (BAW)},
    year = {2016},
    type = {final report},
    address = {B3953.05.04.70002},
    abstract = {Smoothed Particle Hydrodynamics (SPH) is a Lagrangian method for fluid
    dynamic simulations. In the past decades it drew the attention of
    the scientific community for its versatility and the possibility
    to simulate complex phenomena such as e.g. surface tension and fluid-solid
    interactions with floating objects. SPH has in general higher computational
    requirements than the most common Eulerian methods and several different
    models have been proposed for the treatment of boundaries, each with
    advantages and limitations.
    The project aimed to develop, validate and increase the computational
    efficiency of an existing SPH code for hydraulic engineering problems.
    As base code for the development, the GPUSPH simulator has been chosen.
    As the name suggests, it is a SPH implementation which exploits the
    Graphic Processing Units (GPU) to perform the computation of the
    particle to particle interactions. The GPUSPH simulator has been
    developed within the ATHOS Consortium, whose members include universities
    and research institutes from different nations working on different
    aspects of the code. A development branch external to BAW butof particular
    interest for the project regards the newer “Semi-Analytical” boundary
    model, the development of which has been completed only recently.
    In the first phase, several features have been improved or introduced
    in the simulator, especially the capability of splitting a simulation
    across multiple nodes of a cluster each equipped with one or more
    GPU devices. This additional level of parallelism has enabled the
    simulation of high-resolution or spatially big scenarios (more than
    100 million particles).
    In the second phase, two test cases have been developed. The first
    is a fish pass, that has been modeled following the plan of a physical
    scaled model situated in the laboratories of BAW Karlsruhe. Simple
    Lennard-Jones boundaries have been used, featuring “pseudo-open”
    boundaries capable of controlling the inlet flow and specifically
    developed for the test case. A comparison of the simulated flow and
    a set of laboratory measurements highlighted a very good agreement
    in terms of the stream shape, including the recirculation areas.
    The water level were however too high in the simulated model because
    of an excess of friction due to the boundary model.
    A ship lock has been modeled as second test case replicating the new
    Kiel-Holtenau lock, of which a scaled model was built at BAW Karlsruhe.
    The first implementation used the Semi-Analytical boundaries, featuring
    pressure- or velocity-driver open boundaries. Although the first
    results appeared to be promising, the low computational performance
    of the boundary model made a continuation of the tests on a large
    scale infeasible. Since a performance-optimized version of the model
    was not yet available (and is still in progress within the consortium),
    a second attempt has been done with the Dynamic Boundaries, a lighter
    boundary model featuring correct pressure at the boundaries but no
    inlets. The water inflow has been implemented either with “pseudo-inlet”
    and with a piston chamber. Both attempts showed a strong artifact
    causing the stream flow to go upward and hit the ship frontally rather
    than passing under it. This yielded the forces acting on the ship
    to be stronger than the forces measured in a laboratory model at
    BAW. The causes of the difference have been identified with high
    probability in the artificial stream lift caused by the non-physical
    inlet and the excess of friction along the ship hull. Both factors
    could be eliminated with a more physics-adherent boundary model.
    The test cases highlighted the limits of the simpler boundary models
    and the need for an optimized, industrial-level version of the newly
    developed Semi-Analytical boundaries. Although the current development
    status and the first results are very promising for the applicability
    of the method to complex real-life engineering problems, and are
    already being used in the scientific community for many simpler problem
    scenarios, an optimization of the new boundary model is crucial to
    free the high potential of the method and accurately determine its
    application range and characteristics. An additional time of at least
    one year would be required to re-implement both test cases with the
    new model and produce a definitive comparison, granted the availability
    of the consortium members involving the optimization of the boundary
    model.},
    file = {:http\://www.baw.de/content/files/forschung_entwicklung/documents/B3953.05.04.70002.pdf:PDF},
    owner = {jaj},
    timestamp = {2017.02.27},
    url = {http://www.baw.de/DE/wasserbau/forschung_entwicklung/forschung_entwicklung.html}
    }

2014

  • Jankowski, J. A.. (2014). Potential der Intel Many Integrated Core Architektur für die Flussmodellierung – Codes UnTRIM und TELEMAC (Internal ReportNo. A39530510012). BAW.
    [BibTeX] [Download PDF]
    @TECHREPORT{Jankowski2014mic,
    author = {Jankowski, J.A.},
    title = {{Potential der Intel Many Integrated Core Architektur für die Flussmodellierung
    – Codes UnTRIM und TELEMAC}},
    institution = {BAW},
    year = {2014},
    type = {Internal Report},
    number = {A39530510012},
    owner = {jaj},
    timestamp = {2016.08.18},
    url = {http://papers.jankowski.org/intel-many-integrated-core-mic-architecture-and-the-untrim-code}
    }

  • Platzek, F. W., Stelling, G. S., Jankowski, J. A., & Pietrzak, J. D.. (2014). Accurate vertical profiles of turbulent flow in z-layer models. Water Resources Research, 50(3), 2191–2211. doi:10.1002/2013WR014411
    [BibTeX] [Abstract] [Download PDF]

    Three-dimensional hydrodynamic z-layer models, which are used for simulating the flow in rivers, estuaries, and oceans, suffer from an inaccurate and often discontinuous bottom shear stress representation, due to the staircase bottom. We analyze the governing equations and clearly show the cause of the inaccuracies. Based on the analysis, we present a new method that significantly reduces the errors and the grid dependency of the results. The method consists of a near-bed layer-remapping and a modified near-bed discretization of the k − ε turbulence model. We demonstrate the applicability of the approach for uniform channel flow, using a schematized two-dimensional vertical model and for the flow over a bottom sill using the Delft3D modeling system.

    @ARTICLE{Platzek2014a,
    author = {Platzek, F. W. and Stelling, G. S. and Jankowski, J. A. and Pietrzak,
    J. D.},
    title = {Accurate vertical profiles of turbulent flow in z-layer models},
    journal = {Water Resources Research},
    year = {2014},
    volume = {50},
    pages = {2191--2211},
    number = {3},
    abstract = {Three-dimensional hydrodynamic z-layer models, which are used for
    simulating the flow in rivers, estuaries, and oceans, suffer from
    an inaccurate and often discontinuous bottom shear stress representation,
    due to the staircase bottom. We analyze the governing equations and
    clearly show the cause of the inaccuracies. Based on the analysis,
    we present a new method that significantly reduces the errors and
    the grid dependency of the results. The method consists of a near-bed
    layer-remapping and a modified near-bed discretization of the k − ε
    turbulence model. We demonstrate the applicability of the approach
    for uniform channel flow, using a schematized two-dimensional vertical
    model and for the flow over a bottom sill using the Delft3D modeling
    system.},
    doi = {10.1002/2013WR014411},
    issn = {1944-7973},
    keywords = {Hydrodynamic modeling, Turbulence, diffusion, and mixing processes,
    Topographic/bathymetric interactions, Numerical modeling, Hydrodynamics,
    boundary layer flow, z-coordinates, discretization errors, k-epsilon
    turbulence, staircase problem},
    owner = {jaj},
    timestamp = {2015.09.07},
    url = {http://dx.doi.org/10.1002/2013WR014411}
    }

  • Rustico, E., Jankowski, J., Hérault, A., Bilotta, G., & Del Negro, C.. (2014). Multi-GPU, multi-node SPH implementation with arbitrary domain decomposition. Paper presented at the Proceedings of the 9th SPHERIC International Workshop.
    [BibTeX] [Abstract] [Download PDF]

    We present a restructured version of GPUSPH [4], [8], [11], a CUDA-based implementation of SPH. The new version is extended to allow execution on multiple GPUs on one or more host nodes, making it possible to concurrently exploit hundreds of devices across a network, allowing the simulation on larger domains and at higher resolutions. Partitioning of the computational domain is not limited anymore to parallel planes and can follow arbitrary, user-defined shapes at the resolution of individual cells, where the cell is defined by the auxiliary grid used for fast neighbor search. This allows optimal partitioning even in the case of complex domains, such as rivers with Uturns. The version we present also includes many additional features that have been developed on GPUSPH. Particularly important are: the uniform precision work by H´erault et al. [13], which is essential for numerical robustness in the case of very large ratios between the domain size and particle resolution; a compact neighbor list, which allows larger subdomains to be loaded on each device; the semi-analytical boundary conditions by Ferrand et al. [9], [12], and support for floating objects [14]. All of these features are seamlessly supported in single-GPU, multi-GPU and multi-node modes.

    @INPROCEEDINGS{Rustico2014b,
    author = {Rustico, E. and Jankowski, J. and Hérault, A. and Bilotta, G. and
    Del Negro, C.},
    title = {Multi-{GPU}, multi-node {SPH} implementation with arbitrary domain
    decomposition},
    booktitle = {Proceedings of the 9th SPHERIC International Workshop},
    year = {2014},
    editor = {Damien Violeau, Alexis Hérault, Antoine Joly},
    pages = {127--133},
    month = {Paris, France, June, 03-05 2014},
    organization = {CNAM, Paris, France},
    abstract = {We present a restructured version of GPUSPH [4], [8], [11], a CUDA-based
    implementation of SPH. The new version is extended to allow execution
    on multiple GPUs on one or more host nodes, making it possible to
    concurrently exploit hundreds of devices across a network, allowing
    the simulation on larger domains and at higher resolutions. Partitioning
    of the computational domain is not limited anymore to parallel planes
    and can follow arbitrary, user-defined shapes at the resolution of
    individual cells, where the cell is defined by the auxiliary grid
    used for fast neighbor search. This allows optimal partitioning even
    in the case of complex domains, such as rivers with Uturns. The version
    we present also includes many additional features that have been
    developed on GPUSPH. Particularly important are: the uniform precision
    work by H´erault et al. [13], which is essential for numerical robustness
    in the case of very large ratios between the domain size and particle
    resolution; a compact neighbor list, which allows larger subdomains
    to be loaded on each device; the semi-analytical boundary conditions
    by Ferrand et al. [9], [12], and support for floating objects [14].
    All of these features are seamlessly supported in single-GPU, multi-GPU
    and multi-node modes.},
    owner = {jaj},
    timestamp = {2014.06.23},
    url = {http://papers.jankowski.org/multi-gpu-multi-node-sph-implementation-with-arbitrary-domain-decomposition}
    }

2013

  • Jankowski, J. A.. (2013). Adaptierung und Erweiterung von Casulli-Algorithmen für Parallelrechner mit Hardware-Beschleunigung und zur Anwendung von konservativen Advektionsverfahren (AbschlußberichtNo. A39530270001). Bundesanstalt für Wasserbau.
    [BibTeX] [Download PDF]
    @TECHREPORT{Jankowski2013hard,
    author = {Jankowski, J.A.},
    title = {{Adaptierung und Erweiterung von Casulli-Algorithmen für Parallelrechner
    mit Hardware-Beschleunigung und zur Anwendung von konservativen Advektionsverfahren}},
    institution = {Bundesanstalt für Wasserbau},
    year = {2013},
    type = {Abschlußbericht},
    number = {A39530270001},
    month = {Januar 2013},
    note = {62pp.},
    file = {:http\://www.baw.de/content/files/forschung_entwicklung/documents/A39530270001.pdf:PDF},
    owner = {jaj},
    timestamp = {2013.10.30},
    url = {http://papers.jankowski.org/adaptierung-und-erweiterung-von-casulli-algorithmen-fur-parallelrechner-mit-hardware-beschleunigung-und-zur-anwendung-von-konservativen-advektionsverfahren}
    }

2012

  • Jankowski, J. A.. (2012). A hardware-accelerated parallel implementation of a two-dimensional scheme for free surface flows. Paper presented at the Proceedings of HIC 2012 – 10th International Conference on Hydroinformatics, Hamburg, July 14-18, 2012.
    [BibTeX] [Abstract] [Download PDF]

    This contribution concerns the verification and performance assessment of a hardware-accelerated parallel implementation of an algorithm for the semi-implicit finite difference method for solving the vertically integrated shallow water equations including a non-linear treatment of wetting and drying and conservative advection schemes. Instead of adapting an existing serial, OpenMP-, or MPI-parallelised code with all necessary compromises to be met, the selected approach is to write the code from scratch exposing the fine-grained parallelism of the scheme and execute the whole computational kernel of the code on a state-of-the-art streaming processor, i.e. a GPU. The reached speedups compared to a single CPU core are in the order of 20 or 30 for the double or single precision, respectively, which confirms the attractivity of the presently available advanced programming technologies for detailed, high-resolution river modelling applying commodity hardware.

    @INPROCEEDINGS{Jankowski2012,
    author = {Jankowski, J.A.},
    title = {A hardware-accelerated parallel implementation of a two-dimensional
    scheme for free surface flows},
    booktitle = {Proceedings of HIC 2012 -- 10th International Conference on Hydroinformatics,
    Hamburg, July 14-18, 2012},
    year = {2012},
    publisher = {TuTech Verlag},
    note = {Hamburg, Germany},
    abstract = {This contribution concerns the verification and performance assessment
    of a hardware-accelerated parallel implementation of an algorithm
    for the semi-implicit finite difference method for solving the vertically
    integrated shallow water equations including a non-linear treatment
    of wetting and drying and conservative advection schemes. Instead
    of adapting an existing serial, OpenMP-, or MPI-parallelised code
    with all necessary compromises to be met, the selected approach is
    to write the code from scratch exposing the fine-grained parallelism
    of the scheme and execute the whole computational kernel of the code
    on a state-of-the-art streaming processor, i.e. a GPU. The reached
    speedups compared to a single CPU core are in the order of 20 or
    30 for the double or single precision, respectively, which confirms
    the attractivity of the presently available advanced programming
    technologies for detailed, high-resolution river modelling applying
    commodity hardware.},
    url = {http://papers.jankowski.org/a-hardware-accelerated-parallel-implementation-of-a-two-dimensional-scheme-for-free-surface-flows}
    }

  • Platzek, F., Stelling, G. S., Jankowski, J. A., & Patzwahl, R.. (2012). On the representation of bottom shear stress in z-layer models. Paper presented at the Proceedings of HIC 2012 – 10th International Conference on Hydroinformatics, Hamburg, July 14-18, 2012.
    [BibTeX] [Abstract] [Download PDF]

    Bottom friction plays an important role in modelling river flows. In three-dimensional (3D) models, the vertical discretization is commonly based on σ-layers or z-layers. In this paper we focus on a well-known problem encountered when applying z-layers: local truncation errors in the computation of bottom shear stress and near-bed turbulence along a sloping bottom as e.g. in the case of 3D river simulations. This problem stems from the ‘staircase’ representation of the bottom and results in difficulties in the computation of morphological changes. We consider uniform channel flow and analyze the influence of variations in near- bed layer thickness on the local truncation errors in the vertical diffusion term. Application of both an algebraic turbulence model, based on a prescribed mixing-length and the standard k-ε turbulence model to compute the eddy viscosity is investigated. We consider two approaches that reduce the local truncation errors and inspect their applicability for more general flow situations.

    @INPROCEEDINGS{Platzek2012,
    author = {Platzek, F. and Stelling, G.S. and Jankowski, J.A. and Patzwahl,
    R.},
    title = {On the representation of bottom shear stress in z-layer models},
    booktitle = {Proceedings of HIC 2012 - 10th International Conference on Hydroinformatics,
    Hamburg, July 14-18, 2012},
    year = {2012},
    publisher = {TuTech Verlag},
    note = {Hamburg, Germany},
    abstract = {Bottom friction plays an important role in modelling river flows.
    In three-dimensional (3D) models, the vertical discretization is
    commonly based on σ-layers or z-layers. In this paper we focus on
    a well-known problem encountered when applying z-layers: local truncation
    errors in the computation of bottom shear stress and near-bed turbulence
    along a sloping bottom as e.g. in the case of 3D river simulations.
    This problem stems from the ‘staircase’ representation of the bottom
    and results in difficulties in the computation of morphological changes.
    We consider uniform channel flow and analyze the influence of variations
    in near- bed layer thickness on the local truncation errors in the
    vertical diffusion term. Application of both an algebraic turbulence
    model, based on a prescribed mixing-length and the standard k-ε turbulence
    model to compute the eddy viscosity is investigated. We consider
    two approaches that reduce the local truncation errors and inspect
    their applicability for more general flow situations.},
    url = {http://papers.jankowski.org/on-the-representation-of-bottom-shear-stress-in-z-layer-models}
    }

2009

  • Jankowski, J. A.. (2009). Parallel implementation of a non-hydrostatic model for free surface flows with semi-Lagrangian advection treatment. International Journal for Numerical Methods in Fluids, 59(10), 1157–1179. doi:10.1002/fld.1859
    [BibTeX] [Abstract] [Download PDF]

    The parallel implementation of an unstructured-grid, three-dimensional, semi-implicit finite difference and finite volume model for the free surface Navier–Stokes equations (UnTRIM) is presented and discussed. The new developments are aimed to make the code available for high-performance computing in order to address larger, complex problems in environmental free surface flows. The parallelization is based on the mesh partitioning method and message passing and has been achieved without negatively affecting any of the advantageous properties of the serial code, such as its robustness, accuracy and efficiency. The key issue is a new, autonomous parallel streamline backtracking algorithm, which allows using semi-Lagrangian methods in decomposed meshes without compromising the scalability of the code. The implementation has been carefully verified not only with simple, abstract test cases illustrating the application domain of the code but also with advanced, high-resolution models presently applied for research and engineering projects. The scheme performance and accuracy aspects are researched and discussed.

    @ARTICLE{Jankowski2009,
    author = {Jankowski, J.A.},
    title = {Parallel implementation of a non-hydrostatic model for free surface
    flows with semi-Lagrangian advection treatment},
    journal = {International Journal for Numerical Methods in Fluids},
    year = {2009},
    volume = {59},
    pages = {1157--1179},
    number = {10},
    abstract = {The parallel implementation of an unstructured-grid, three-dimensional,
    semi-implicit finite difference and finite volume model for the free
    surface Navier–Stokes equations (UnTRIM) is presented and discussed.
    The new developments are aimed to make the code available for high-performance
    computing in order to address larger, complex problems in environmental
    free surface flows. The parallelization is based on the mesh partitioning
    method and message passing and has been achieved without negatively
    affecting any of the advantageous properties of the serial code,
    such as its robustness, accuracy and efficiency. The key issue is
    a new, autonomous parallel streamline backtracking algorithm, which
    allows using semi-Lagrangian methods in decomposed meshes without
    compromising the scalability of the code. The implementation has
    been carefully verified not only with simple, abstract test cases
    illustrating the application domain of the code but also with advanced,
    high-resolution models presently applied for research and engineering
    projects. The scheme performance and accuracy aspects are researched
    and discussed.},
    doi = {10.1002/fld.1859},
    keywords = {parallel; free surface; non-hydrostatic; semi-Lagrangian; unstructured
    grid; UnTRIM},
    url = {http://onlinelibrary.wiley.com/doi/10.1002/fld.1859/abstract}
    }

2008

  • Jankowski, J. A.. (2008). Mathematical model UnTRIM – MPI version manual (Technical Report). Bundes\-anstalt für Wasser\-bau, Karlsruhe.
    [BibTeX] [Download PDF]
    @TECHREPORT{Jankowski2008mpi,
    author = {Jankowski, J.A.},
    title = {{Mathematical model UnTRIM -- MPI version manual}},
    institution = {Bundes\-anstalt für Wasser\-bau, Karlsruhe},
    year = {2008},
    type = {Technical Report},
    note = {Version August 2008 (1.0), 55~pp.},
    file = {manual_mpi_untrim.pdf:http\://www.baw.de/downloads/wasserbau/mathematische_verfahren/pdf/:PDF},
    url = {http://papers.jankowski.org/mathematical-model-untrim-mpi-version-manual}
    }

  • Patzwahl, R., Jankowski, J. A., & Lege, T.. (2008). Very high resolution numerical modelling for inland waterway design. Paper presented at the Proceedings of the International Conference on Fluvial Hydraulics (River Flow 2008).
    [BibTeX] [Abstract] [Download PDF]

    The paper discusses the advantages and disadvantages of numerical modelling of rivers with a grid of very high resolution using the new MPI version of UnTRIM as the computational engine. The main aim of the investigation is to assess the economy of this approach taking especially into account the effort required for the mesh generation and its modification, which is usually laborious in the case of coarser meshes requiring exact reproduction of structure lines defining the flow. In the first step the results of a low-resolution Telemac-2D grid are compared to the results obtained for the same river stretch topography with a high-resolution UnTRIM model. In the second step the results of two- and three-dimensional modelling applying a high-resolution mesh based on a high quality digital terrain model are studied. It is concluded that under the assumption of appropriate computational resources readily available, the high-resolution modelling reduces significantly the effort required for the initial model set-up and for adjustments due to changes in the model topography. The calibration, parametrisation and validation of the models is simplified without affecting the accuracy, freeing the engineer to concentrate on the project aims and not bypass the weak points of the methodology.

    @INPROCEEDINGS{Patzwahl2008,
    author = {Patzwahl, R. and Jankowski, J.A. and Lege, T.},
    title = {Very high resolution numerical modelling for inland waterway design},
    booktitle = {Proceedings of the International Conference on Fluvial Hydraulics
    (River Flow 2008)},
    year = {2008},
    note = {Izmir, Turkey, 2008},
    abstract = {The paper discusses the advantages and disadvantages of numerical
    modelling of rivers with a grid of very high resolution using the
    new MPI version of UnTRIM as the computational engine. The main aim
    of the investigation is to assess the economy of this approach taking
    especially into account the effort required for the mesh generation
    and its modification, which is usually laborious in the case of coarser
    meshes requiring exact reproduction of structure lines defining the
    flow. In the first step the results of a low-resolution Telemac-2D
    grid are compared to the results obtained for the same river stretch
    topography with a high-resolution UnTRIM model. In the second step
    the results of two- and three-dimensional modelling applying a high-resolution
    mesh based on a high quality digital terrain model are studied. It
    is concluded that under the assumption of appropriate computational
    resources readily available, the high-resolution modelling reduces
    significantly the effort required for the initial model set-up and
    for adjustments due to changes in the model topography. The calibration,
    parametrisation and validation of the models is simplified without
    affecting the accuracy, freeing the engineer to concentrate on the
    project aims and not bypass the weak points of the methodology.},
    url = {http://papers.jankowski.org/very-high-resolution-numerical-modelling-for-inland-waterway-design}
    }

2007

  • Jankowski, J. A.. (2007). Further developments of UnTRIM: parallel implementation and its verification. Paper presented at the Proceedings of the IAHR Fifth International Symposium on Environmental Hydraulics, (ISEH V), Tempe, Arizona, USA.
    [BibTeX] [Abstract] [Download PDF]

    This contribution deals with further developments of UnTRIM, an unstructured-grid, three-dimensional, semi-implicit finite difference finite volume model for the shallow water equations (Casulli, 2002). Attractive numerical properties of the method like its robustness due to the unlimited stability and successes in practical applications spawned efforts aimed at making the available code fit for the high performance computing in order to address larger, complex problems in hydraulic engineering. The paper concentrates on the parallel implementation of the program, based on the domain decomposition method and message passing, which has been achieved without negatively affecting any of the properties of the serial code. A special attention is paid to a new, autonomous parallel streamline backtracking algorithm, which allows using semi-Lagrangian methods in decomposed meshes without compromising the scalability of the code. The new developments have been carefully verified not only with the numerous simple, abstract test cases illustrating the application domain of the code, but also with advanced, high resolution models presently applied for research and engineering projects.

    @INPROCEEDINGS{Jankowski2007,
    author = {Jankowski, J.A.},
    title = {{Further developments of UnTRIM: parallel implementation and its
    verification}},
    booktitle = {Proceedings of the IAHR Fifth International Symposium on Environmental
    Hydraulics, (ISEH V)},
    year = {2007},
    address = {Tempe, Arizona, USA},
    organization = {IAHR},
    publisher = {IAHR},
    abstract = {This contribution deals with further developments of UnTRIM, an unstructured-grid,
    three-dimensional, semi-implicit finite difference finite volume
    model for the shallow water equations (Casulli, 2002). Attractive
    numerical properties of the method like its robustness due to the
    unlimited stability and successes in practical applications spawned
    efforts aimed at making the available code fit for the high performance
    computing in order to address larger, complex problems in hydraulic
    engineering. The paper concentrates on the parallel implementation
    of the program, based on the domain decomposition method and message
    passing, which has been achieved without negatively affecting any
    of the properties of the serial code. A special attention is paid
    to a new, autonomous parallel streamline backtracking algorithm,
    which allows using semi-Lagrangian methods in decomposed meshes without
    compromising the scalability of the code. The new developments have
    been carefully verified not only with the numerous simple, abstract
    test cases illustrating the application domain of the code, but also
    with advanced, high resolution models presently applied for research
    and engineering projects.},
    owner = {jaj},
    timestamp = {2013.10.09},
    url = {http://papers.jankowski.org/further-developments-of-untrim-parallel-implementation-and-its-verification}
    }

2001

  • Jankowski, J. A., & Zielke, W.. (2001). The mesoscale sediment transport due to technical activities in the deep sea. Deep Sea Research Part II: Topical Studies in Oceanography, 48(17–18), 3487–3521. doi:10.1016/S0967-0645(01)00054-6
    [BibTeX] [Abstract] [Download PDF]

    This paper presents a mesoscale model for sediment transport in the deep sea resulting from technical activities such as manganese nodule mining. The model includes the temporal variability of ambient currents, the modification of the water density due to suspended sediments (density driven flow), bottom boundary-layer effects, and the influence of flocculation on the sediment settling velocity. It yields the three-dimensional sediment concentration and the bottom blanketing for time periods of up to a few weeks in areas of up to a few hundred square kilometers. The model also allows simulation of the mobilization, sorption and the transport of heavy metals. Two applications are presented. One treats the sediment transport during the NOAA Benthic Impact Experiment. The other is concerned with dispersion of heavy metals, including the interaction with suspended sediment in the Disturbance and Recolonization Experiment Experimental Area. The model is highly sophisticated with regard to the processes and numerical methods. Nevertheless, a final conclusion concerning the quantification of its prognostic capability for industrial scale operations cannot presently be drawn because of the lack of complete and coherent data sets.

    @ARTICLE{Jankowski2001a,
    author = {Jankowski, J.A. and Zielke, W.},
    title = {The mesoscale sediment transport due to technical activities in the
    deep sea},
    journal = {Deep Sea Research Part II: Topical Studies in Oceanography},
    year = {2001},
    volume = {48},
    pages = {3487--3521},
    number = {17--18},
    note = {Environmental Impact Studies for the Mining of Polymetallic Nodul
    es from the Deep Sea},
    abstract = {This paper presents a mesoscale model for sediment transport in the
    deep sea resulting from technical activities such as manganese nodule
    mining. The model includes the temporal variability of ambient currents,
    the modification of the water density due to suspended sediments
    (density driven flow), bottom boundary-layer effects, and the influence
    of flocculation on the sediment settling velocity. It yields the
    three-dimensional sediment concentration and the bottom blanketing
    for time periods of up to a few weeks in areas of up to a few hundred
    square kilometers. The model also allows simulation of the mobilization,
    sorption and the transport of heavy metals. Two applications are
    presented. One treats the sediment transport during the NOAA Benthic
    Impact Experiment. The other is concerned with dispersion of heavy
    metals, including the interaction with suspended sediment in the
    Disturbance and Recolonization Experiment Experimental Area. The
    model is highly sophisticated with regard to the processes and numerical
    methods. Nevertheless, a final conclusion concerning the quantification
    of its prognostic capability for industrial scale operations cannot
    presently be drawn because of the lack of complete and coherent data
    sets.},
    doi = {10.1016/S0967-0645(01)00054-6},
    owner = {jaj},
    timestamp = {2013.10.09},
    url = {http://www.sciencedirect.com/science/article/pii/S0967064501000546}
    }

  • Oebius, H. U., Becker, H. J., Rolinski, S., & Jankowski, J.. (2001). Parametrization and evaluation of marine environmental impacts produced by deep-sea manganese nodule mining. Deep Sea Research Part II: Topical Studies in Oceanography, 48(17–18), 3453–3467. doi:http://dx.doi.org/10.1016/S0967-0645(01)00052-2
    [BibTeX] [Abstract] [Download PDF]

    The evaluation of marine environmental impacts resulting from the exploitation of marine resources requires the numerical description, parametrization, and modelling of such processes in order to be able to transfer, compare, and forecast the effects of anthropogenic activities in the deep sea. One of the controversial effects is the formation and behaviour of sediment clouds as a consequence of anthropogenic activities on the seafloor. Since there is a need for reliable data, two subprojects of the “Interdisciplinary Deep-sea Environmental Protection Group (TUSCH)”-project “Impacts from Technical Activities on the Deep-Sea Ecosystem of the South East Pacific Offshore Peru (ATESEPP)” were devoted to the assembly of such data. Based on the German technical approach for deep-sea mining, the possible environmental impacts by a miner were estimated, the impacts on the seafloor were simulated and investigated by tests with large volume undisturbed sediment samples on board the research vessel and in the laboratory, and the results were evaluated and extrapolated. This report gives a comprehensive presentation of the physical problems, the technical approach, and the results of these investigations.

    @ARTICLE{Oebius99a,
    author = {Horst U. Oebius and Hermann J. Becker and Susanne Rolinski and Jacek
    A. Jankowski},
    title = {Parametrization and evaluation of marine environmental impacts produced
    by deep-sea manganese nodule mining},
    journal = {Deep Sea Research Part II: Topical Studies in Oceanography },
    year = {2001},
    volume = {48},
    pages = {3453--3467},
    number = {17–18},
    note = {Environmental Impact Studies for the Mining of Polymetallic Nodul
    es from the Deep Sea},
    abstract = {The evaluation of marine environmental impacts resulting from the
    exploitation of marine resources requires the numerical description,
    parametrization, and modelling of such processes in order to be able
    to transfer, compare, and forecast the effects of anthropogenic activities
    in the deep sea. One of the controversial effects is the formation
    and behaviour of sediment clouds as a consequence of anthropogenic
    activities on the seafloor. Since there is a need for reliable data,
    two subprojects of the “Interdisciplinary Deep-sea Environmental
    Protection Group (TUSCH)”-project “Impacts from Technical Activities
    on the Deep-Sea Ecosystem of the South East Pacific Offshore Peru
    (ATESEPP)” were devoted to the assembly of such data. Based on the
    German technical approach for deep-sea mining, the possible environmental
    impacts by a miner were estimated, the impacts on the seafloor were
    simulated and investigated by tests with large volume undisturbed
    sediment samples on board the research vessel and in the laboratory,
    and the results were evaluated and extrapolated. This report gives
    a comprehensive presentation of the physical problems, the technical
    approach, and the results of these investigations.},
    doi = {http://dx.doi.org/10.1016/S0967-0645(01)00052-2},
    issn = {0967-0645},
    url = {http://www.sciencedirect.com/science/article/pii/S0967064501000522}
    }

2000

  • Hervouet, J. M., & Jankowski, J. A.. (2000). Comparing numerical simulations of free surface flows using non-hydrostatic Navier-Stokes and Boussinesq equations. Paper presented at the Proceedings of the 4th Conference on Hydroinformatics, Iowa City, Iowa (USA).
    [BibTeX] [Download PDF]
    @INPROCEEDINGS{Hervouet2000,
    author = {Hervouet, J. M. and Jankowski, J.A.},
    title = {Comparing numerical simulations of free surface flows using non-hydrostatic
    Navier-Stokes and Boussinesq equations},
    booktitle = {Proceedings of the 4th Conference on Hydroinformatics},
    year = {2000},
    address = {Iowa City, Iowa (USA)},
    owner = {jaj},
    timestamp = {2016.04.17},
    url = {http://papers.jankowski.org/comparing-numerical-simulations-of-free-surface-flows-using-non-hydrostatic-navier-stokes-and-boussinesq-equations}
    }

1999

  • Jankowski, J. A.. ((1999). A non-hydrostatic model for free surface flows.). PhD Thesis.
    [BibTeX] [Download PDF]
    @PHDTHESIS{Jankowski98D,
    author = {Jankowski, J.A.},
    title = {{A non-hydrostatic model for free surface flows}},
    school = {Universität Hannover},
    year = {1999},
    note = {Bericht Nr. 56/1999, Institut für Strömungsmechanik und ERiB},
    file = {:http\://papers.jankowski.org/wp-content/uploads/d.pdf:PDF},
    url = {http://papers.jankowski.org/a-non-hydrostatic-model-for-free-surface-flows}
    }

  • Weilbeer, H., & Jankowski, J. A.. (1999). A Three-Dimensional Non-Hydrostatic Model for Free Surface Flows: Development, Verification and Limitations. Paper presented at the Proceedings of the 6th International Conference on Estuarine and Coastal Modeling, New Orleans, Louisiana, United States.
    [BibTeX] [Abstract] [Download PDF]

    The theoretical background of a new finite-element non-hydrostatic model for simulation of free surface flows based on the fractional step method and pressure decomposition is presented. One of the verification cases concerning the solitary wave propagation is provided. Further developments concerning more sophisticated turbulence modelling for practical applications as flows around structures or scour formation are discussed and illustrated with preliminary, but very promising results.

    @INPROCEEDINGS{Weilbeer1999,
    author = {H. Weilbeer and J. A. Jankowski},
    title = {A Three-Dimensional Non-Hydrostatic Model for Free Surface Flows:
    Development, Verification and Limitations},
    booktitle = {Proceedings of the 6th International Conference on Estuarine and
    Coastal Modeling},
    year = {1999},
    editor = {Malcolm L. Spaulding and H. Lee Butler},
    pages = {162--177},
    address = {New Orleans, Louisiana, United States},
    month = {November 3--5},
    organization = {ASCE, American Society of Civil Engineers},
    publisher = {ASCE},
    abstract = {The theoretical background of a new finite-element non-hydrostatic
    model for simulation of free surface flows based on the fractional
    step method and pressure decomposition is presented. One of the verification
    cases concerning the solitary wave propagation is provided. Further
    developments concerning more sophisticated turbulence modelling for
    practical applications as flows around structures or scour formation
    are discussed and illustrated with preliminary, but very promising
    results.},
    file = {:http\://papers.jankowski.org/wp-content/uploads/weilbeer_jankowski_zielke_1999.pdf:PDF},
    keywords = {Water flow; Free surfaces; Three-dimensional models; Finite element
    method; Turbulence},
    owner = {jaj},
    timestamp = {2013.10.09},
    url = {http://papers.jankowski.org/a-threedimensional-non-hydrostatic-model-for-free-surface-flows-development-verification-and-limitations}
    }

1997

  • Jankowski, J. A., & Zielke, W.. (1997). Data support for modelling of deep-sea mining impacts. Paper presented at the Proceedings of the Seventh (1997) International Offshore and Polar Engineering Confrence, Honolulu, USA.
    [BibTeX] [Abstract] [Download PDF]

    The paper critically reviews the presently available experimental data from various tests and experiments connected with the deepsea mining issue with regard to their feasibility in supporting and validating the developed numerical models. Numerical modelling is applied mainly to predetermining the plume development and sea floor blanketing caused by various sediment discharges. The paper describes processes included in these models and discusses the experimental acquisition of needed model parameters. The existing models and their validation are shortly reviewed and parameters essential to operate and validate them are pointed out. Recommendations for further field studies are given in order to improve the quality of model forecasts.

    @INPROCEEDINGS{Jankowski97,
    author = {Jankowski, J.A. and Zielke, W.},
    title = {Data support for modelling of deep-sea mining impacts},
    booktitle = {Proceedings of the Seventh (1997) International Offshore and Polar
    Engineering Confrence, Honolulu, USA},
    year = {1997},
    volume = {I},
    pages = {451--460},
    publisher = {International Society of Offshore and Polar Engineers},
    abstract = {The paper critically reviews the presently available experimental
    data from various tests and experiments connected with the deepsea
    mining issue with regard to their feasibility in supporting and validating
    the developed numerical models. Numerical modelling is applied mainly
    to predetermining the plume development and sea floor blanketing
    caused by various sediment discharges. The paper describes processes
    included in these models and discusses the experimental acquisition
    of needed model parameters. The existing models and their validation
    are shortly reviewed and parameters essential to operate and validate
    them are pointed out. Recommendations for further field studies are
    given in order to improve the quality of model forecasts.},
    url = {http://papers.jankowski.org/data-support-for-modelling-of-deep-sea-mining-impacts}
    }

1996

  • Jankowski, J. A., Malcherek, A., & Zielke, W.. (1996). Numerical modeling of suspended sediment due to deep-sea mining. Journal of Geophysical Research: Oceans, 101(C2), 3545–3560. doi:10.1029/95JC03564
    [BibTeX] [Abstract] [Download PDF]

    A numerical model was developed in order to estimate the residence time of a sediment plume generated by potential deep-sea mining activities, with special attention to discharges in the bottom boundary layer. The site of the Disturbance and Recolonization Experiment (DISCOL) in the Peru Basin in the southeast Pacific Ocean was chosen as a case study. The model includes the actual bathymetry, as well as the characteristic flow patterns of this region. Various aspects affecting the transport and sedimentation of the plume, such as stratification, flocculation in a sediment-laden water column, and the hydrodynamics are discussed in conjunction with field data and studied with the overall aim of providing a reliable risk assessment of deep-sea mining environmental impacts.

    @ARTICLE{Jankowski95a,
    author = {Jankowski, J.A. and Malcherek, A. and Zielke, W.},
    title = {Numerical modeling of suspended sediment due to deep-sea mining},
    journal = {Journal of Geophysical Research: Oceans},
    year = {1996},
    volume = {101},
    pages = {3545--3560},
    number = {C2},
    abstract = {A numerical model was developed in order to estimate the residence
    time of a sediment plume generated by potential deep-sea mining activities,
    with special attention to discharges in the bottom boundary layer.
    The site of the Disturbance and Recolonization Experiment (DISCOL)
    in the Peru Basin in the southeast Pacific Ocean was chosen as a
    case study. The model includes the actual bathymetry, as well as
    the characteristic flow patterns of this region. Various aspects
    affecting the transport and sedimentation of the plume, such as stratification,
    flocculation in a sediment-laden water column, and the hydrodynamics
    are discussed in conjunction with field data and studied with the
    overall aim of providing a reliable risk assessment of deep-sea mining
    environmental impacts.},
    doi = {10.1029/95JC03564},
    issn = {2156-2202},
    url = {http://papers.jankowski.org/numerical-modeling-of-suspended-sediment-due-to-deep-sea-mining}
    }

1995

  • Jankowski, J. A., & Zielke, W.. (1995). Mesoskalige Stofftransporte im Pazifik als Folge des Tiefseebergbaus (Final Report). Institut für Strömungsmechanik und ERiB, Universität Hannover.
    [BibTeX] [Download PDF]
    @TECHREPORT{Jankowski95,
    author = {Jankowski, J.A. and Zielke, W.},
    title = {{Mesoskalige Stofftransporte im Pazifik als Folge des Tiefseebergbaus}},
    institution = {Institut für Strömungsmechanik und ERiB, Universität Hannover},
    year = {1995},
    type = {Final Report},
    note = {86 pp.},
    url = {http://papers.jankowski.org/mesoskalige-stofftransporte-im-pazifik-als-folge-des-tiefseebergbaus}
    }

  • Zielke, W., Jankowski, J. A., Sündermann, J., & Segschneider, J.. (1995). Numerical Modelling of Sediment Transport Caused by Deep Sea Mining. Paper presented at the Proceedings of the First (1995) ISOPE – Ocean Mining Symposium, Tsukuba, Japan.
    [BibTeX] [Abstract] [Download PDF]

    The paper describes the application of mesoscale and large scale models in order to simulate the impact of deep sea mining sediment discharges on the marine environment. The modelling efforts are crosslinked with the experiments of the Tusch research group which provide supporting data. The results yield time-dependent and three-dimensional concentration fields, the amount of redeposition, and the plume residence time. The emissions at the bottom lead to an impact mainly at a local scale, whereas contamination in the larger areas due to discharges at the free surface or in some intermediate depth cannot be excluded.

    @INPROCEEDINGS{Zielke1995,
    author = {Zielke, W. and Jankowski, J.A. and Sündermann, J. and Segschneider,
    J.},
    title = {Numerical Modelling of Sediment Transport Caused by Deep Sea Mining},
    booktitle = {Proceedings of the First (1995) ISOPE - Ocean Mining Symposium},
    year = {1995},
    pages = {157--161},
    address = {Tsukuba, Japan},
    month = {November 21--22},
    publisher = {ISOPE},
    abstract = {The paper describes the application of mesoscale and large scale models
    in order to simulate the impact of deep sea mining sediment discharges
    on the marine environment. The modelling efforts are crosslinked
    with the experiments of the Tusch research group which provide supporting
    data. The results yield time-dependent and three-dimensional concentration
    fields, the amount of redeposition, and the plume residence time.
    The emissions at the bottom lead to an impact mainly at a local scale,
    whereas contamination in the larger areas due to discharges at the
    free surface or in some intermediate depth cannot be excluded.},
    owner = {jaj},
    timestamp = {2013.10.09},
    url = {http://papers.jankowski.org/numerical-modelling-of-sediment-transport-caused-by-deep-sea-mining}
    }

1994

  • Jankowski, J. A., Malcherek, A., & Zielke, W.. (1994). Numerical modeling of sediment transport processes caused by deep sea mining discharges. Paper presented at the Proceedings of the OCEANS 94 Conference, Brest.
    [BibTeX] [Abstract] [Download PDF]

    A numerical model was developed in order to estimate the residence time of a sediment plume generated by deep-sea mining activities. The model is capable of simulating density currents in a sediment-laden ocean bottom boundary layer. The numerical model was verified using an analytical solution, which does not take into account the above menioned effects. The results show that due to density differences the residence time of a plume is reduced substantially.

    @INPROCEEDINGS{Jankowski94b,
    author = {Jankowski, J.A. and Malcherek, A. and Zielke, W.},
    title = {Numerical modeling of sediment transport processes caused by deep
    sea mining discharges},
    booktitle = {Proceedings of the OCEANS 94 Conference, Brest},
    year = {1994},
    volume = {III},
    pages = {269--276},
    publisher = {IEEE/SEE},
    abstract = {A numerical model was developed in order to estimate the residence
    time of a sediment plume generated by deep-sea mining activities.
    The model is capable of simulating density currents in a sediment-laden
    ocean bottom boundary layer. The numerical model was verified using
    an analytical solution, which does not take into account the above
    menioned effects. The results show that due to density differences
    the residence time of a plume is reduced substantially.},
    url = {http://papers.jankowski.org/numerical-modeling-of-sediment-transport-processes-caused-by-deep-sea-mining-discharges}
    }

  • Jankowski, J. A., & Zielke, W.. (1994). Mesoskalige Stofftransporte im Pazifik als Folge des Tiefseebergbaus (Report). Institut für Strömungsmechanik und ERiB, Universität Hannover.
    [BibTeX] [Download PDF]
    @TECHREPORT{Jankowski94,
    author = {Jankowski, J.A. and Zielke, W.},
    title = {{Mesoskalige Stofftransporte im Pazifik als Folge des Tiefseebergbaus}},
    institution = {Institut für Strömungsmechanik und ERiB, Universität Hannover},
    year = {1994},
    type = {Report},
    note = {Bericht Nr. JJ/01/1994, 66 pp.},
    url = {http://papers.jankowski.org/mesoskalige-stofftransporte-im-pazifik-als-folge-des-tiefseebergbaus}
    }

1993

  • Jankowski, J. A., & Zielke, W.. (1993). Mesoskalige Stofftransporte im Pazifik als Folge des Tiefseebergbaus (Report). Institut für Strömungsmechanik und ERiB, Universität Hannover.
    [BibTeX] [Download PDF]
    @TECHREPORT{Jankowski93,
    author = {Jankowski, J.A. and Zielke, W.},
    title = {{Mesoskalige Stofftransporte im Pazifik als Folge des Tiefseebergbaus}},
    institution = {Institut für Strömungsmechanik und ERiB, Universität Hannover},
    year = {1993},
    type = {Report},
    note = {Bericht Nr. JJ/01/1993, 136 pp.},
    url = {http://papers.jankowski.org/mesoskalige-stofftransporte-im-pazifik-als-folge-des-tiefseebergbaus}
    }

1992

  • Malcherek, A., Jankowski, J. A., & Hoyme, H.. (1992). SEACLOUD: Ein analytisches Modell zur Berechnung des mesoskaligen Stofftransports als Folge des Tiefseebergbaus (Report). Institut für Strömungsmechanik und ERiB, Universität Hannover.
    [BibTeX]
    @TECHREPORT{Malcherek92S,
    author = {Malcherek, A. and Jankowski, J.A. and Hoyme, H.},
    title = {{SEACLOUD: Ein analytisches Modell zur Berechnung des mesoskaligen
    Stofftransports als Folge des Tiefseebergbaus}},
    institution = {Institut für Strömungsmechanik und ERiB, Universität Hannover},
    year = {1992},
    type = {Report},
    note = {(Bericht Nr. AM/003/1992), 144 pp.}
    }