Tag Archives: hydrodynamics

Assessment of a parallel implementation of a two-dimensional scheme for free surface flows using a GPU

J.A. Jankowski

Abstract: The rapid changes in the present computer architectures throw questions concerning the future of the hardware-oriented programming based on the usage of heterogeneous parallel computing resources, consisting of nodes of interconnected, but separate CPUs and GPUs. However, it is believed that the sustainability of the programming efforts nowadays is to be searched in the fact that the principle source of the performance of the present GPUs as well as the emerging APUs is the hardware acceleration of vector operations. Therefore, this contribution delivers an assessment of a hardware-accelerated parallel implementation of a principal algorithm for a vertically integrated finite difference scheme for free surface flows including non-linear treatment of wetting and drying. Continue reading

Coupling Telemac and Sisyphe internally

Jacek A. Jankowski. Coupling Telemac and Sisyphe internally, 9th Telemac User Club, Karlsruhe, 17-18 October 2002.

One of the disadvantages of the Telemac system is the traditional public library software structure based on of freely linkable Fortran functions with open parameter lists, being a legacy from the original Fortran-77 development in 1980-years. Fortran-90 modules are presently applied only for providing global variables of the system components, which is an incomplete solution. This works well with vertical programs-libraries hierarchy, but when a horizontal coupling between libraries or programs is necessary, awkward and unnecessary problems appear, alone due to the overlapping names of variables and the input/output conflicts.

The presentation proposes the encapsulation of the Telemac system principal components in the form of proper Fortran-90 modules providing correct module interfaces. Continue reading

Parametrization and evaluation of marine environmental impacts produced by deep-sea manganese nodule mining

Oebius, H.U., Becker, H.J., Rolinski, S., Jankowski, J.A.

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. Continue reading

The mesoscale sediment transport due to technical activities in the deep sea

J.A. Jankowski and W. Zielke

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. Continue reading

Comparing numerical simulations of free surface flows using non-hydrostatic Navier-Stokes and Boussinesq equations

Jean-Michel Hervouet and Jacek A. Jankowski

Abstract. The numerical solutions of three-dimensional, non-hydrostatic Navier-Stokes equations are compared to the ones obtained with Boussinesq equations in the case of a solitary wave in a rectangular channel. Continue reading