|3D application of the continuous modelling concept to mud slides in open seas|
|Le Hir, P.; Cayocca, F. (2002). 3D application of the continuous modelling concept to mud slides in open seas, in: Winterwerp, J.C. et al. (Ed.) (2002). Fine sediment dynamics in the marine environment. Proceedings in Marine Science, 5: pp. 545-562|
|In: Winterwerp, J.C.; Kranenburg, C. (Ed.) (2002). Fine sediment dynamics in the marine environment. Proceedings in Marine Science, 5. Elsevier: Amsterdam. ISBN 0-444-51136-9. XV, 713 pp., more|
|In: Proceedings in Marine Science. Elsevier: Amsterdam. ISSN 1568-2692, more|
turbidity current; sediment transport; mathematical modelling
Most turbidity current models are vertically integrated, and use a parametric entrainment rate to simulate the growth and dilution of the dense layer. The continuous modelling concept integrates all physical processes related to high-concentrated suspensions (stratification-induced turbulence damping, hindered settling and molecular viscosity increase or even viscoplastic behaviour). It is applied in a three-dimensional frame to simulate turbidity currents on a slope. A sensitivity analysis has been carried out in a 2DV configuration. It shows the front celerity is dependent on the initial mass, not so much on the slope, whereas the velocity within the body of the turbidity current is controlled by the slope and vertical mixing processes. The resulting entrainment rate is in agreement with flume experiments. A vertical recirculation is observed at the head of the turbidity current. The contribution of bed erosion is pointed out: such an erosion is generated by the density current and then enhances the density gradient and thus the turbidity current. The application of the 3D model to the 1979 Nice slide and turbidity current is under process. Preliminary results are discussed.